POSTEROVÁ SEKCE B

Iron oxide magnetic nanoparticles belong to one of the most extensively studied classes of magnetic nanomaterials. While their magnetic properties and biocompatibility are well recognized, their surface chemistry offers additional functionality, including the intrinsic ability to adsorb and even reduce other species. These properties arise from the nanoparticles’ high specific surface area, which can reach several hundred m² g⁻¹, as well as from their reductive capacity, which naturally decreases with a declining Fe²⁺/Fe³⁺ ratio—that is, upon transitioning from stoichiometric magnetite to maghemite nanoparticles.
In this study, we leverage the redox-active Fe²⁺/Fe³⁺ couple for the direct reduction of Au⁺ precursors and their subsequent anchoring onto a reactive magnetic iron oxide platform in a single-step process. A systematic investigation revealed that the oxidation state of iron critically governs the catalytic performance of the resulting materials. In addition to the oxidation state, we examined the influence of magnetic carrier particle size and noble metal loading on catalytic activity.
Notably, catalysts prepared using the finely tuned native reductive and adsorptive properties of the magnetic supports achieved catalytic activities exceeding those of more sophisticated systems requiring additional stabilizing and anchoring agents or chemical reductants. These findings demonstrate that magnetite and maghemite nanoparticles function not merely as passive carriers but as active participants in catalyst formation and performance. This approach simplifies the synthesis, minimizes chemical waste, and yields highly efficient, magnetically recoverable catalysts suitable for sustainable applications.

Fuel cells arise as a perspective technology for energy storage and related conversion of chemical energy into electrical energy. Among them, direct methanol fuel cell (DMFC) is promising candidate due to its high energy density, easy handling of methanol and green production of methanol. Platinum is widely used catalyst for methanol oxidation reaction (MOR) but suffers from poisoning by adsorbed intermediates and high price. Thus, the actual research trends are focused on the minimalization of Pt amounts in the catalyst structure with conservation of overall efficiency. In this work, we propose plasmon assisted catalysis as an efficient photoelectrochemical technique. This method is based on the generation of hot charge carriers which can boost the overall MOR efficiency. We prepared Pt catalyst on gold nanoparticles decorated Ti3C2 MXene to better exploit visible light spectrum with combining two plasmon-active components: gold and MXene. The applicability of the prepared material for MOR was confirmed by cyclic voltammetry and chronoamperometric measurements. Furthermore, the contribution of both plasmon active centres was examined. It has been shown that MXene serves as an efficient substrate for Pt anchoring, but gold provides stronger enhancement of achieved current density. Proposed approach allows us to significantly decrease the amounts of Pt used and to efficiently utilize visible light for photo-electrochemistry.

Surface modification of carbon nanotubes (CNTs) with protonic acids is a simple method for tuning their structural, electronic, and electrocatalytic properties [1]. Acid treatment introduces oxygen-containing functional groups onto the CNT surface and modifies its electronic structure, which affects the electrochemical performance of the material [2]. The aim of this work was to investigate the influence of sulfuric acid (H₂SO₄), nitric acid (HNO₃), and acetic acid (CH₃COOH) on the electronic structure, sheet resistance, and electrocatalytic properties of CNTs.
CNT films were immersed in the selected acid solutions and characterized by Raman spectroscopy, sheet resistance measurements, and linear sweep voltammetry. Electrochemical measurements toward the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) were carried out in 0.1M KOH using a rotating glassy carbon disk electrode (3 mm diameter) at 1600 rpm and a scan rate of 10 mV s⁻¹.
The largest increase in the Raman G-band frequency was observed for H₂SO₄-treated CNTs, where ωG increased from 1572.96 cm⁻¹ to 1604.56 cm⁻¹. The lowest sheet resistance was obtained for CNT/HNO₃ (2.12 × 10³ Ω/sq), whereas CNT/H₂SO₄ exhibited 3.47 × 10³ Ω/sq. The CNT/H₂SO₄ electrode showed the highest OER activity with the lowest overpotential (η₁₀ = 558 mV), whereas CNT/HNO₃, CNT/CH₃COOH, and pristine CNTs exhibited 676, 655, and 830 mV, respectively. Acid treatment also modified the HER onset potential. The results demonstrate that the electrocatalytic performance of CNTs is governed primarily by acid-induced changes in their electronic structure rather than by sheet resistance alone. The proposed protonic acid doping strategy offers a simple route toward carbon-based electrode materials for alkaline water electrolysis, where efficient HER and OER electrocatalysts are required [3].
ACKNOWLEDGEMENTS: The research was partiall supported by the Ministry of Science and Higher Education under the program ‘Regional Initiative of Excellence’ in years 2024-2027, Project No. RID/SP/0048/2024/01.
REFERENCES:[1] Hirsch A., Functionalization of Single-Walled Carbon Nanotubes, Angew. Chem. Int. Ed., 41 (2002), 1853-1859; [2] Sezer N., Koç M., Oxidative Acid Treatment of Carbon Nanotubes, Surfaces and Interfaces, 14 (2019), 1-8; [3] Lu X., Yim W.-L., Suryanto B.H.R., Zhao C., Electrocatalytic Oxygen Evolution at Surface-Oxidized Multiwall Carbon Nanotubes, J. Am. Chem. Soc., 137 (2015), 2901-2907.

Mechanically mediated atom transfer radical polymerization (mechanoATRP) utilizes piezoelectric materials to promote catalyst regeneration under mechanical stimulation. While ZnO has emerged as an efficient piezoelectric agent for mechanoATRP, the influence of its structural state on polymerization performance remains unexplored. Here, ZnO particles were subjected to ball milling to investigate how this mechanical treatment affects their ability to mediate the mechanoATRP of methyl acrylate. Ball-milled ZnO exhibited markedly enhanced polymerization activity compared with pristine ZnO under otherwise identical reaction conditions. The enhancement was particularly pronounced during the initial stage of polymerization and was accompanied by improved control over the molar-mass distribution while maintaining good agreement between the experimental and theoretical molar masses. These observations demonstrate that the performance of ZnO in mechanoATRP is not determined solely by its chemical composition but can be substantially altered by mechanical processing. The findings suggest that the structural state of piezoelectric agents represents an important and largely overlooked parameter in the development of efficient mechanoATRP systems.
ACKNOWLEDGEMENTS: The authors gratefully acknowledge financial support from the Czech Science Foundation (GA25-16538S). M. Cvek, M. Masař, and M. Machovský acknowledge the project DKRVO (RP/CPS/2024-28/007), and M. Mrlík acknowledges DKRVO (RP/CPS/2024-28/003), funded by the Ministry of Education, Youth and Sports of the Czech Republic.

Fe₅(PO₄)₄(OH)₃·2H₂O is a green crystalline compound that, according to the literature, has mostly been investigated for photocatalysis [1] and as a precursor for lithium iron phosphate batteries [2]. Despite the numerous Fe₅(PO₄)₄(OH)₃·2H₂O morphologies reported [3], morphology control and its influence on catalytic properties remain insufficiently explored. This study focuses on the hydrothermal synthesis of Fe₅(PO₄)₄(OH)₃·2H₂O in the presence of the disodium salt of β-glycerophosphate (GPH). Under hydrothermal conditions, GPH serves as a phosphate source that undergoes gradual homogeneous hydrolysis, allowing greater control over crystal growth, which could be beneficial for preparing various morphologies. In this work, several morphologies were obtained by varying the Fe:P ratio, reaction time, temperature, and the concentrations of FeCl₃ and GPH. Although the photocatalytic activity of Fe₅(PO₄)₄(OH)₃·2H₂O is moderate, calcination is suggested as one way to address this limitation. FePO₄ (α-quartz-type structure), formed by calcination of Fe₅(PO₄)₄(OH)₃·2H₂O, is particularly interesting because it is piezoelectric and could thus be used in piezocatalysis. Because morphology is preserved after calcination, precursor design enables indirect tailoring of piezocatalytic properties. This strategy opens a new research direction for exploiting Fe₅(PO₄)₄(OH)₃·2H₂O as a precursor to prepare piezoelectric material, which, to the best of our knowledge, has not yet been reported in the literature.
REFERENCES: [1] Martins, P. M. et al., Chemosphere, 2021, 262, 128300. https://doi.org/10.1016/j.chemosphere.2020.128300; [2] Lv, C. et al., CrystEngComm, 2017, 19, 1253-1257. https://doi.org/10.1039/C6CE02512A; [3] Duan, X. et al., Chem. Eur. J., 2013, 19, 7231-7242. https://doi.org/10.1002/chem.201300385.

The creation of electrocatalysts with high activity, selectivity, and durability is a major issue in the sustainable shift to a net-zero economy. Here, we have coordinated 5-cyanoisophthalate with Rh(II) paddlewheel units to create Rh2[5-cyano-isophthalic acid]24 (RhMOP-CN). Using catalyst-modified gas diffusion electrodes (GDE), RhMOP-CN was assessed for the electrochemical CO2 reduction reaction. It demonstrated CO/H2 ratio of roughly 1:1 with Faradaic efficiencies (FE) of FECO = 51.6% and FEH2 = 44.1% at a current density of 15 mA cm-2 and FECO = 51.2% and FEH2 = 51.1% at 25 mA cm-2. Additionally, RhMOP-CN's better syngas selectivity was demonstrated by the synthesis of a variety of Rh MOPs with various surface functional groups (proton, sulfonate, and amine). RhMOP-CN's exceptional endurance and stability over virgin metal-organic frameworks (MOF)/MOP catalysts in long-term applications are further demonstrated by the fact that its structural integrity held up even after thorough alkaline treatment and post-electrocatalytic assessments. Additionally, Rh centers and surface groups stabilize eCO2RR intermediates, improving CO selectivity, according to DFT modeling. This work emphasizes how functional groups and metal centers work together to provide effective dual-site catalysts for the electrochemical conversion of CO2 to syngas.

Atmospheric-pressure plasma treatment has been widely investigated as an environmentally friendly approach for improving fibre-matrix adhesion in natural fibre composites. In this work, flax fabrics were treated using Diffuse Coplanar Surface Barrier Discharge (DCSBD) and Volume Dielectric Barrier Discharge (VDBD) prior to manufacturing multilayer composites with polyurethane (PU) foils. The influence of plasma treatment on interfacial adhesion, tensile and flexural properties was evaluated.
T-peel testing demonstrated a pronounced improvement in laminate interfacial adhesion after DCSBD treatment, whereas VDBD produced only a moderate enhancement. The superior performance of DCSBD is attributed to its more homogeneous surface activation, leading to stronger bonding between the flax fabric and the PU film. However, despite the significantly higher peel strength, neither tensile nor flexural tests showed a corresponding increase in the mechanical performance of the composites. In most cases, prolonged plasma exposure resulted in a slight reduction of strength, indicating that the overall mechanical behaviour was governed by factors other than interfacial adhesion, such as fibre integrity, laminate architecture or impregnation quality.
Although the improved interfacial adhesion did not result in higher static tensile or flexural properties, the marked increase in peel strength suggests that plasma treatment effectively modifies the fibre-matrix interface. This enhanced interface is expected to play a more significant role under e.g. long-term environmental exposure or cyclic loading, where interfacial degradation becomes a dominant failure mechanism.

Glass fibre reinforced polymer (GFRP) composites are increasingly used in civil engineering applications due to their favourable mechanical properties, low weight and corrosion resistance. The performance of these materials is strongly influenced by the fibre-matrix interface, which is affected by the chemical and physical properties of the fibre sizing. Modification of the sizing layer can provide a way to influence the surface properties of glass fibres and their adhesion behaviour. Plasma treatment can introduce polar functional groups onto the fibre surface, which may modify surface energy and influence adhesion with polymer matrices. In this work, glass fibres were treated using a diffuse coplanar surface barrier discharge (DCSBD) plasma jet operated with nitrogen and synthetic air as working gases. The influence of plasma treatment on the surface chemistry of the fibre sizing was investigated by X-ray photoelectron spectroscopy (XPS). Changes in adhesion behaviour after plasma treatment were evaluated using a Scotch tape test. The comparison of nitrogen and synthetic air plasma treatments provides information about the effect of the working gas on the surface modification process. The results provide insight into the effect of DCSBD plasma jet treatment and working gas composition on the surface modification of glass fibre sizing.

The laboratory trials were carried out to evaluate the resistance of building stone surfaces to algal biofouling. A porous quartz sandstone material with high water absorption was selected as the substrate material, which was treated with a hydrophobic poly(alkyl siloxane)-based coating containing photoactive exfoliated g-C3N4 nanoparticles. The sandstone plates (95 × 20 × 5 mm) were submerged in glass cultivation columns (i.d. 37 mm) containing a culture of the microalga Chlorella vulgaris. Three types of samples were investigated: untreated sandstone, sandstone treated with poly(alkyl siloxane) coating, and sandstone treated with the poly(alkyl siloxane) coating incorporating g-C3N4 nanoparticles. The cultivation columns were illuminated with a VIS source (continuous photosynthetically active radiation at 650 µmol m-2 s-1). After 10 days of exposure, the microalgal growth was evaluated. In the second series, comparative trials were carried out in a flow-through chamber using the same materials and the same algal species. The microalgal culture was allowed to flow over the surfaces of coated and uncoated sandstone plates (100 × 40 × 10 mm) at regular intervals while being exposed to the same type of illumination. The results demonstrated both the advantages and the limitations of the proposed testing methodologies and provided a basis for the further development of procedures for evaluating photoactive coatings for building stone.

This study investigated the influence of hexagonal boron nitride (h-BN) nanoparticles incorporated into glass ionomer cement (GIC) on its chemical composition and mechanical performance. The GIC was modified with 0.5 wt.% and 1.0 wt.% h-BN, and the successful incorporation of the nanoparticles was confirmed using chemical analysis. The mechanical performance of the modified materials was assessed by measuring compressive strength, flexural strength, and surface microhardness testing. The incorporation of h-BN nanoparticles resulted in a slight, but statisticant, increase in compressive strength. In contrast, flexural strength was enhanced, particularly in specimens containing 0.5 wt.% h-BN. However, specimens containing 1.0 wt.% h-BN exhibited greater scatter in the measured flexural strength values, suggesting a less homogeneous dispersion of nanoparticles within the GIC matrix. Surface microhardness increased significantly in the 1.0 wt.% h-BN group (p < 0.05), indicating improved resistance of the material surface to localised plastic deformation. Overall, the results demonstrate that incorporating h-BN nanoparticles can enhance the surface mechanical performance of GIC without adversely affecting its bulk mechanical properties. The effectiveness of the reinforcement, however, depends strongly on nanoparticle concentration and dispersion within the matrix. These findings highlight the potential of h-BN nanoparticles as a reinforcing nanofiller for GICs and provide a basic for further optimisation of nanoparticle distribution and evaluation of the long-term mechanical stability and clinical performance of the modified materials.

Maintaining the cleanliness of building facades, particularly glass surfaces requires significant water consumption and high maintenance costs especially in high-rise urban environments. This work aims to develop an environmentally friendly self-cleaning glass through nano-scale surface engineering to achieve hydrophobic behavior and reduce dust accumulation. The glass surface was modified using nano-scale laser surface structuring followed by chemical surface treatment to enhance water repellency without the need for detergents or frequent manual cleaning. The hydrophobic performance of the modified glass was evaluated through water contact angle and sliding angle measurements. In addition, the optical transmittance of the nano-structured glass was experimentally measured to investigate the influence of surface modification on light transmission properties. The study also discusses the potential impact of controlled optical transmittance on reducing solar heat gain through building facades, which may contribute to lowering cooling energy demand in buildings. Future work will focus on evaluating the thermal performance and economic feasibility of the proposed approach including potential reductions in water consumption and facade cleaning costs. The proposed concept demonstrates the potential of nano-structured hydrophobic glass as a sustainable solution for energy-efficient and low-maintenance building facades.

The development of advanced lithium-assisted nitrogen reduction reaction (li-NRR) requires improved control over electrochemical lithium deposition. In particular, reducing the energy required for lithium-ion reduction and controlling interfacial processes are of considerable interest for ammonia production and middle conditions. Plasmonic nanostructures offer a promising approach to influence electrochemical reactions through light-induced localized electromagnetic fields and injection of hot chargé carriers. In this work, we investigate the effect of plasmonic excitation on the Li+ electrochemical reduction on plasmon active mesoporous Au (mAu) surface.
The mASu surfcae were created using the micelle-assisted approach. The presence of mesoporous and plasmonics properties were confirmed using SEM and UV-Vis measurements
Subsequently, an electrochemical cell was assembled using a platinum counter-electrode, mAu working electrode and a silver wire as the reference electrode. Tetrahydrofuran (THF) containing lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was used as the electrolyte. Prior to the electrochemical measurements, the lithium salt was dried to minimize residual moisture, while the electrochemical cell was purged with argon to establish an inert atmosphere. During electrochemical experiments, aimed on the Li reduction on mAu surface, the mesoporous gold electrode was illuminated with wide spectrum light source to excite localised surface plasmon(s). The photoelectrochemical measurements revealed a pronounced change in the lithium reduction behavior upon plasmonic excitation, indicating that illumination facilitates the electrochemical deposition of lithium compared with the non-illuminated system.
The state of deposited lithium was investigated by the range of characterisation methods, with the main attention on the oxidation state, formation of undesired Li oxide, carbonate and fluoride. Especial attention was focused on the surface morphology and Li distribution across pAu surface as well as on the Li reactivity. Obtained results allow to claim that plasmon excitation can be involved electrochemical processes relevant to Li-NRR and future energy-conversion technologies.
ACKNOWLEDGEMENTS: This work was supported by the project 26-22285S.

Magnesium is considered as one of the most promising materials for solid-state hydrogen storage mainly due to its high gravimetric hydrogen capacity and low weight. However, the practical utilization of magnesium-based systems is significantly hindered by the high thermodynamic stability of magnesium hydride (MgH₂) and its inherently slow hydrogen sorption kinetics. Therefore, the development of effective catalysts capable of enhancing the hydrogenation and dehydrogenation behavior of magnesium remains an important research objective. In the present study, the catalytic effect of two different MAX phases (commercial and experimental) on the formation kinetics of MgH₂ was systematically investigated. The composite materials were prepared by mechanically mixing commercially available magnesium powder with MAX phases possessing a comparable particle size. The blending procedure was performed manually using a laboratory mortar inside a glovebox under a purified inert atmosphere. This preparation strategy was selected to preserve the initial particle size of the magnesium powder and to achieve a sufficiently homogeneous distribution of the MAX phases on the particle surfaces. Furthermore, it minimized the influence of particle size reduction and the introduction of severe structural defects, allowing the catalytic contribution of the MAX phases to be evaluated independently of these additional factors. Hydrogenation experiments were carried out using a Sieverts-type apparatus (Setaram PCTPro). The hydrogen absorption kinetics were measured within the temperature range of 250-350 °C. The effect of the MAX phases on both the hydrogen absorption and desorption kinetics was assessed and compared with the behaviour of unmodified magnesium powder.

TiO₂ nanotube (TNT) layers represent promising nanostructured semiconductor platforms for sensing [1,2], photoelectrochemical [3] and electronic applications. Their functional properties strongly depend on crystallinity and phase composition, which can be tailored by post-synthesis annealing. Previous works have shown that MoS2 decorated TNT layers are very promising anodes in Li-ion batteries [4] and for photocatalytic gas -phase decomposition of model organic pollutants [5].
In this work, TiO₂ nanotubes, decorated byMoS₂ nanoflakes using Atomic Layer Deposition (ALD) are investigated with respect to their electrical response and thermally induced structural evolution. Special attention is paid to the presence of different TiO₂ crystalline phases, such as anatase and rutile, whose formation is governed by the annealing temperature. The combination of TiO₂ nanotubular morphology with MoS₂ nanoflakes on their surfaceand additional ALD TiO₂ interlayer,is expected to influence charge transport both in-plane as well as through-plane of the TiO₂ nanotubes. The study aims to correlate annealing temperature, phase composition and MoS₂ surface modification with changes in the electrical characteristics of the hybrid nanostructure.
ACKNOWLEDGEMENT: We acknowledge CzechNanoLab Research Infrastructure (ID 90251), supported by MEYS CR.
REFERENCES: [1] S. Ng et al., Adv. Eng. Mater. 2017, 1700589; [2] S. Ng et al., ACS Appl. Mater. Interfaces 2020, 12, 33386−33396; [3] R. Zazpe et al., Nanoscale 2018, 10, 16601; [4] H. Sopha, FlatChem 2019, 17 100130; [5] M. Motola et al., Nanoscale 2019, 11, 23126; [6] H. Simunkova et al., Ms in preparation.

Electrochemical energy storage requires high-energy, high-power, mechanically flexible devices that remain competitive when realistic metrics are applied. Transition-metal-based electrodes, including metal sulfides, offer rich redox chemistry, but typically underperform in devices because of insulating interfaces, particle coarsening, and sluggish charge transport. Here, we employ graphene acid (GA) for the directed sulfidation of ZIF‑8 crystals toward a seamless ZnS/GA architecture. Zn-carboxylate coordination unlocks ZnS redox activity, while interfacial bonding suppresses aggregation and insulating sulfur-rich species. This prevents GA restacking and affords a mesoporous, higher-surface-area architecture with improved proton access and fast charge transport, confirmed by scanning electrochemical microscopy (SECM). These properties enable effective operation without heavy metallic foam current collectors, yielding superior full-electrode-mass metrics (including current collector mass) relative to prior systems. A ZnS/GA∥GA asymmetric solid-state supercapacitor with a PVA-H2SO4 gel electrolyte and an ultrathin graphite-foil current collector operates at 2.0 V. It achieves 27.6 Wh/kg at 2.1 kW/kg with 92% retention after 5000 cycles and stable performance under extreme bending. This approach offers a versatile route to overcome metal sulfide limitations and unlock their redox properties for flexible energy storage.
ACKNOWLEDGEMENTS: V.S. thanks the EU Marie Skłodowska-Curie program (101107732). Funding is acknowledged from the EU REFRESH project (CZ.10.03.01/00/22_003/0000048, OP Just Transition), ERDF/ESF TECHSCALE (CZ.02.01.01/00/22_008/0004587), Czech Science Foundation (22-27973K), and NanoEnviCz infrastructure (MEYS project LM2023066).

Alkaline fuel cells (AFCs) are promising energy-conversion systems as they allow the use of non-precious metal catalysts. However, their wider implementation requires further improvement of several key components, including catalysts and anion exchange membranes (AEMs). Developing AEMs that combine adequate performance with sustainability therefore remains an important research challenge. Bacterial nanocellulose (BnC) is a promising material for AEM development because it is renewable and offers high mechanical strength, a nanofibrous structure and good dimensional stability. However, its low ionic conductivity limits its direct use in AFCs. In this study, BnC-based membranes were modified in situ by adding a quaternisation agent directly to the culture medium during biosynthesis. This approach introduced ion-conducting groups as the BnC network formed. The membranes were characterised using attenuated total reflectance Fourier-transform infrared spectroscopy, X-ray diffraction and Scanning electron microscopy. Their dimensional stability, alkali uptake and ionic conductivity were also evaluated. Spectroscopic analysis confirmed the in situ modification, while scanning electron microscopy showed that the characteristic nanofibrous structure of BnC was retained. The modified membranes exhibited higher ionic conductivity than unmodified and maintained their structural integrity during conductivity measurements. These results indicate that in situ modification during biosynthesis is a promising strategy for preparing ion conductive BnC-based membranes for alkaline fuel cell applications.
ACKNOWLEDGEMENTS: The authors acknowledge the financial support of the Slovenian Research and Inovation Agency (grant numbers Z2-60175, J2-50086, N2-0388, P2-0118.

Electrochemical oxygen reduction to hydrogen peroxide through the two-electron pathway offers a sustainable alternative to the energy-intensive anthraquinone process, yet controlling the intrinsic selectivity of earth-abundant hydroxide catalysts remains challenging. Here, we introduce a lanthanide single-atom engineering strategy to regulate the peroxide pathway in β-Ni(OH)₂ for selective electrochemical H₂O₂ production. Atomically dispersed Ce, Gd, and Yb sites were incorporated into the Ni(OH)₂ framework to perturb the local electronic structure, oxygen-binding environment, and interfacial reaction microenvironment without forming separate lanthanide phases. Rotating ring-disk electrode measurements in O₂-saturated alkaline electrolyte reveal a pronounced lanthanide-dependent modulation of the oxygen reduction pathway. Among the investigated catalysts, Gd-Ni(OH)₂ exhibits the strongest preference for the two-electron route, with an electron-transfer number approaching 2.16, corresponding to an estimated H₂O₂ selectivity of approximately 92%, compared with an electron-transfer number of 2.80 for pristine Ni(OH)₂. The contrasting behaviour of Ce-, Gd-, and Yb-modified samples demonstrates that peroxide selectivity is governed not merely by lanthanide incorporation, but by the specific electronic and coordination perturbations introduced by each isolated metal centre. The lanthanide sites are proposed to regulate *OOH binding and suppress O-O bond cleavage, thereby redirecting oxygen reduction away from the competing four-electron pathway. This work establishes lanthanide single-atom incorporation as a versatile approach for engineering the intrinsic peroxide pathway of transition-metal hydroxides and provides a design framework for developing inexpensive and selective electrocatalysts for decentralized H₂O₂ production.

Carbon materials are widely used as anode materials in lithium-ion batteries due to their good electrical conductivity, chemical stability and ability to reversibly store lithium. Graphite remains the most commonly used anode material, however, the development of novel carbon nanostructures offers opportunities to modify anode properties and their behavior during long-term electrochemical cycling.
The aim of this study is to determine the influence of nanodiamond addition to graphite on the electrochemical properties and cycling stability of anode materials and to assess the potential of composites based on nanodiamond and graphite for application in lithium-ion battery anodes.
This study investigates anode materials based on nanodiamond and nanodiamond/graphite composites, with graphite used as a reference material. Combining nanodiamonds, characterized by a carbon structure with a high sp³ contribution, with rich in sp² graphite enables the preparation of materials with different proportions of these carbon structures and allows their influence on electrode properties to be investigated.
The materials are used to prepare composite electrodes on copper current collectors, which are subsequently assembled into lithium half-cells with metallic lithium as the counter electrode. The study includes structural and morphological characterization of the materials, together with evaluation of their electrochemical performance during repeated galvanostatic charge and discharge cycling. Particular attention is given to changes occurring within the active electrode material during cell operation. Comparison of the electrodes before and after cycling is used to evaluate their structural stability and identify morphological changes associated with repeated lithium storage and release.
This work was supported by the bilateral Polish-Czech project “Sp² and sp³ Hybridized Carbon Nanostructures for Energy Storage Applications” (PAN-24-20).

The development of efficient catalysts for electrochemical hydrogenation (ECH) requires precise control over active-site distribution and substrate-catalyst interactions. Herein, we present a post-synthetic functionalization strategy for engineering metal-organic frameworks (MOFs) with nitrogen-rich coordination environments. The introduced functional groups facilitate strong metal-support interactions and enable effective regulation of the catalyst’s electronic and surface properties.
The structural integrity and chemical environment of the functionalized material were systematically examined using X-ray diffraction, Fourier-transform infrared spectroscopy, solid-state 13C NMR, electron microscopy, X-ray absorption spectroscopy, and X-ray photoelectron spectroscopy. These analyses confirm successful framework modification, uniform distribution of the catalytically active species, and strong coordination between the metal centers and nitrogen-containing ligands.
Electrochemical measurements demonstrate enhanced hydrogenation activity and product selectivity compared with the unmodified framework. This improvement arises from the synergistic interaction between the active metal centers and their tailored coordination environment, which promotes reactant adsorption and activation while regulating hydrogen adsorption. The modified catalyst also suppresses the competing hydrogen-evolution reaction, thereby improving hydrogen-utilization efficiency.
This work demonstrates that post-synthetic MOF functionalization offers a versatile strategy for controlling active-site coordination and catalytic behavior. The findings provide useful guidance for designing selective and efficient electrocatalysts for hydrogenation reactions.

In this paper, the novel P-N junction of bismuth oxychloride (BiOCl) and bismuth sulfide (Bi2S3) was synthesized and evaluated in photodetector applications. It was found via DFT modelling that the bandgap of both materials is 2.49 and 1.33 eV, respectively. Experimental studies show slight differences, especially for bismuth oxychloride. Photoelectrical characterization of the device with classic gold electrodes showed that the responsivity towards a wavelength of 629 nm is 8.95 mA/W, while for a wavelength of 940 nm it is 2.77 mA/W. Application of electrodes made out of boron-doped diamond (BDD) allowed for the formation of a P-N-P junction, facilitating charge transfer, due to the formation of additional depletion regions at the interface between Bi2S3 and BDD. This significantly improved the responsivity of the photodetector. For wavelengths of 629 nm and 940 nm, it was found to be 39.34 mA/W and 24.82 mA/W, respectively. Additionally, the specific detectivity of the device with BDD electrodes was improved by one order of magnitude in comparison to that with gold electrodes. This proves that boron-doped diamond is a promising electrode material for application in devices utilizing n-type semiconductors or P-N junctions.

The catalytic hydrogenation of CO₂ to methane is a promising route for renewable energy storage and carbon utilization. The activity and stability of Ni-based catalysts are strongly influenced by the size and dispersion of active Ni species. In conventional microporous zeolites, Ni particles are mainly located on the external crystal surface, making them susceptible to sintering and deactivation.
In this work, hierarchical micro-mesoporous ZSM-5 zeolites were employed as supports for nanoconfined Ni catalysts. The mesoporous network enabled the incorporation of Ni nanoclusters within the zeolite structure, resulting in improved dispersion and stabilization of metallic Ni sites. Structural characterization confirmed that nanoconfinement effectively suppressed particle growth compared with catalysts supported on purely microporous ZSM-5.
The nanoconfined catalysts exhibited significantly higher CO₂ methanation activity, particularly in the low-temperature region. Enhanced catalytic performance is attributed to improved Ni dispersion, reduced sintering, and increased stability of active sites provided by confinement within the mesoporous system. These results demonstrate that nanoconfinement in hierarchical zeolites is an effective strategy for designing highly active and stable catalysts for sustainable CO₂ valorisation.
ACKNOWLEDGEMENTS: This work was supported by the Technology Agency of the Czech Republic (TS01030146), the Czech Science Foundation (25-16545S), and the Research Infrastructure NanoEnviCz funded by the Ministry of Education, Youth and Sports of the Czech Republic (No. LM2023066).

Development of an efficient solar-driven catalyst for hydrogen (H2) production is crucial for addressing global energy demands. Transition metal dichalcogenides (TMDs) and two-dimensional (2D) materials, especially MXenes, are getting a lot of interest because they have outstanding electronic and catalytic properties. A simple one-step hydrothermal method was used to fabricate nanocomposites such as MoSe2/Nb2C (X) (where X = 5, 10, 15, 20%), and they were characterized using different sophisticated analytical methods. Photocatalytic H2 production experiments were conducted in a methanol-water solution under visible light, demonstrating that the MoSe2/Nb2C 10 % heterostructure exhibits superior activity compared with bare Nb2C, MoSe2 and other composites. The better photocatalytic performance of MoSe2/Nb2C occurs because electrons can move between the MoSe2 and Nb2C layers, which helps create more electron-hole pairs. The MoSe2/Nb2C 10 % composite achieved the highest H2 evolution rate, which is attributed to enhanced interfacial electron transfer and reduced recombination. Electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) studies confirmed improved charge-separation kinetics. This work highlights the potential of 2D MoSe2/Nb2C as a high-performance, cost-effective photocatalyst for renewable H2 production, providing insights into the design of advanced MXene-based hybrid materials for solar energy conversion.

Electrospinning is a cost-effective technique for producing nanofibers with high surface area and interconnected porosity. Incorporating nanoparticles provides additional functionality but increases process complexity and makes optimisation of spinning conditions more challenging. The aim of this study was to develop an industrially scalable electrospinning process for the inclusion of MXenes into a poly(ethylene oxide) (PEO) dispersion using a needle-less electrospinning, and thus, fabricate a stable high-capacitance MXene-incorporated fibrous network for wearable electronic applications, i.e., sensors, energy harvesting and storage systems, real-time monitoring of healthcare, personal thermal management, etc. Herein, the influence of electrospinning dispersion on the morphological, structural, chemical, and functional features of newly prepared PEO/MXene nanocomposites was evaluated using Scanning Electron Microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR) and the four-probe electrical resistivity technique. The obtained SEM and FTIR results showed the successful preparation of the nanofibrous net, in which the form and concentration of MXenes influenced the conductivity and viscosity of the dispersions and, consequently, the morphology of the electrospun net. PEO/MXene nanocomposites exhibited sufficient electrical conductivity through the formation of electrically connected pathways while preserving the intrinsic advantages of electrospun PEO mats, including flexibility, low weight, high porosity, and suitability for wearable electronics.
ACKNOWLEDGEMENTS: The results leading to this work were funded by the Slovenian Research and Innovation Agency (ARIS) in the frame of research projects no. J2-50087, Z2-60175 and BI-VB/25-27-022, and a program group for Textile Chemistry and Advanced Textile Materials, P2-0118.

Scaling chemical vapor deposition (CVD) of diamond thin films from traditional substrates (ø2÷4 inches) to sizes >6 inches remains a significant technological challenge. Maintaining sufficiently uniform microwave plasma conditions, substrate temperature, nucleation density, and growth rate over areas spanning several tens of centimeters requires careful optimization. Simultaneously, large-area intrinsic and boron-doped diamond films are increasingly demanded for advanced electronic, sensing, and electrochemical applications.
Diamond research group in Prague has undergone a continuous scale-up over more than two decades. Initial diamond deposition was established in 2002 on 2 inch substrates (focused plasma in ellipsoid resonator), followed by expansion to a 4 inch deposition area in 2008 (linear antenna plasma). Building on these experiences, and in close collaboration with company scia Systems GmbH, a proof-of-concept demonstration of diamond deposition on 12 inch (30 cm) silicon substrates was successfully achieved in 2026.
Our first attempts for large-area deposition revealed pronounced spatial variations in diamond growth and identified several technological limitations, including non-uniform seeding, substrate heating variations, plasma asymmetry, and linear antenna degradation. The knowledge gained from these systematic experimental studies guided subsequent optimization of substrate preparation, deposition conditions, and sequential substrate rotation during the diamond growth.
Following process optimization, intrinsic and boron-doped polycrystalline diamond films with thickness of >1 μm were grown on 12 inch Si substrate. Thickness mapping across the entire 30 cm substrate revealed a smooth and approximately axisymmetric profile. Radial thickness variation was below 10% within the central 5 inch-diameter region. Scanning electron microscopy revealed continuous faceted polycrystalline grains and Raman spectroscopy confirmed the characteristic diamond peak ~1332 cm⁻¹ across the wafer.
Such proof-of-concept experiments demonstrate significant progress toward wafer-scale diamond deposition using a linear-antenna distributed microwave plasma source and establish a technological basis for further optimization of both intrinsic and boron-doped diamond films. Current efforts are focused on the development of large-area boron-doped diamond electrodes for sensing, electrochemical applications and high-power electronic devices.

Barium titanate (BaTiO3) nanoparticles are a promising material to be utilized in mechanically induced atom transfer radical polymerization (mechano-ATRP) due to their ferroelectric and piezoelectric properties. These particles are used in mechano-ATRP to facilitate the initiation and propagation of the polymerization. This is achieved by applying mechanical stimuli, such as ultrasound, to a mixture of monomer with suitable particles.
The hydrothermal method is widely used for the synthesis of fine and uniform BaTiO3 powders in a single step. Furthermore, this method is more energy-efficient and works with safer solvents compared to solid-state synthesis and sol-gel methods, respectively. Nevertheless, balancing the synthesis conditions and the properties of the final powder remains a challenge.
This work explores the hydrothermal synthesis of BaTiO3 nanoparticles with multiple varying parameters, allowing for different particle formations. The morphology, crystal structure, and phase composition of the synthesized particles were analysed employing scanning electron microscopy and X-ray diffraction methods.
The most significant factor influencing the final properties of the BaTiO3 powders was the
OH− ion concentration. A lower OH− concentration led to the formation of finer, less pure powders, while a higher OH− concentration produced larger particles with no or a minimal amount of by-products. The ratio between precursors had an impact on the tetragonality of the synthesized particles.
Interestingly, the highest mechanoATRP activity was observed for the finer, high-surface-area nanopowders, while highly tetragonal particles with a pronounced local ferroelectric response were inactive. These results indicate that mechanoredox performance is not governed by tetragonality or piezoelectric response alone, but is strongly influenced by particle size, accessible surface area, and local structural characteristics.

Due to their hierarchical porosity and chemical properties, foamed geopolymer composites represent promising inorganic sorbents for environmental applications. This work focuses on a systematic evaluation of the effect of varying foaming intensities on the structure and sorption behaviour toward model organic contaminants. The geopolymers were prepared with varying aluminium powder contents and two different fillers, which allowed for control of the ratio of macro- to mesoporous structures while preserving micropores in the matrix. Characterization includes the determination of open porosity and pore structure using optical microscopy. Sorption properties are investigated in batch tests with an emphasis on sorption screening. The study focuses on identifying the relationship between the degree of foaming, the availability of active surface sites and effect of pH changes in solution, with the aim of contributing to the optimization of geopolymer sorbents for the removal of organic pollutants from the aquatic environment.

Nickel-iron (NiFe) electrocatalysts are promising low-cost alternatives to noble-metal-based catalysts for hydrogen production by alkaline water electrolysis. Their catalytic performance is strongly influenced by the composition and morphology of the deposited coating. In this work, the effect of two surfactants, sodium dodecyl sulfate (SDS) and Dolapix CE64 (DPIX), on NiFe coatings electrodeposited on nickel foam was investigated.
NiFe coatings were prepared on nickel foam at current densities of 8, 12 and 16 A·dm⁻². Their morphology and elemental composition were characterized by scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDX). The electrochemical performance of the prepared electrodes was evaluated by load measurements in a zero-gap alkaline electrolyzer equipped with an anion-selective membrane.
The results showed that both the surfactant type and deposition current density significantly affected the Ni/Fe ratio and surface morphology of the coatings. Increasing the current density promoted Fe incorporation, with the most pronounced effect observed for DPIX-containing coatings, where the Ni content decreased from approximately 56 wt.% to 17 wt.%, while the Fe content increased to approximately 53 wt.%. All NiFe-coated electrodes exhibited better performance than uncoated nickel foam. The most pronounced improvement was observed for DPIX-containing electrodes, for which the electrolyzer performance improved with increasing deposition current density. In contrast, SDS-containing coatings showed no significant dependence on deposition current density.
The results demonstrate that surfactant selection, particularly the use of DPIX, is an effective approach to controlling the composition and morphology of NiFe coatings and improving their performance in zero-gap alkaline water electrolysis.

Surface modification of nanoscale zero-valent iron (nZVI) with low-valent sulfur compounds is a promising approach for groundwater remediation. Although several field studies of sulfidated nZVI (S-nZVI) have been reported, experience with its full-scale implementation remains limited. Here, we evaluated the field-scale performance and transformation of S-nZVI in one of the largest full-scale applications reported to date, involving the injection of 150 kg of commercial S-nZVI (NANOFER 25DS, NANO IRON, Czech Republic) into an aquifer heavily contaminated with chlorinated hydrocarbons (CHCs).
The material was pressure-injected into permanent wells as an aqueous suspension (~3 g/L). Trichloroethylene was the dominant contaminant, reaching concentrations of up to 10 mg/L. S-nZVI application increased pH, decreased redox potential, and promoted the formation of gaseous CHC degradation products, including ethane, ethene, and acetylene. Groundwater monitoring showed a decrease in total CHC concentrations for up to six months in highly contaminated deeper horizons. Dehalogenation biomarkers (16S rRNA, vcrA, DHC-RT, Dsb, EtnC, and EtnE) were also monitored. A decrease in their abundance coincided with increased total iron concentrations, particularly in the subsurface gravel aquifer at 8 m b.g.l. and in clayey sands at 13-17 m b.g.l. XRD analysis of recovered solids revealed S-nZVI transformation products after 11 months, with trebeurdenite as the dominant mineral.
These findings demonstrate the applicability of S-nZVI for full-scale in situ treatment while highlighting the interactions between geochemical changes, nanomaterial transformation, and microbial dehalogenation processes under real aquifer conditions.

Per- and polyfluoroalkyl substances (PFAS) are persistent, mobile environmental contaminants that pose significant risks to human health and ecosystems, driving the need for effective and affordable removal technologies. This study presents the development of novel biochar-cyclodextrin (CD) polymer composites as cost-effective adsorbents for PFAS removal from aqueous environments.
The main objective was to reduce the amount of CD polymer required in the adsorbent system, thereby lowering material costs while maintaining or improving adsorption performance. Several biochar-based composites, varying in biochar type and proportion, were synthesized and evaluated against pristine CD polymer. Based on these preliminary adsorption results, one composite was selected for more comprehensive characterization.
Detailed kinetic and isotherm experiments were conducted to elucidate the adsorption behavior and underlying mechanisms of PFAS uptake. Additionally, the effects of water composition and dissolved organic matter were investigated to assess the material's performance under environmentally relevant conditions.
Notably, the selected biochar-CD composite exhibited adsorption properties that, in some cases, exceeded those of the pure cyclodextrin polymer. These findings demonstrate the strong potential of biochar-cyclodextrin composites as low-cost, high-performance adsorbents for PFAS remediation in water treatment applications.

MAX phases are ternary layered carbide or nitride compounds that combine the properties of metals and ceramics offering a broad range of technological applications. Ti-Al-C based MAX phases belong to the most often studied. This work focuses on the preparation of Ti-Al-C based MAX phases using TiC, food packaging material as a source of aluminum and commercial titanium. The first part focuses on the synthesis of titanium carbide (TiC) in molten salt at 1250 °C using Ti powder and an ecofriendly alternative carbon source prepared by carbonizing spent Yerba Mate waste. In the second step, as-prepared TiC and aluminum from food packaging were used to synthesize the MAX phase. The main goal was the utilization of secondary sources of aluminum and carbon for the synthesis of high-tech material, significantly increasing the sustainability of the entire process. The influence of the annealing temperature, ball milling duration, single-stage versus two-stage grinding, and sample compaction on the resulting phase purity was monitored. Individual samples were subsequently characterized using X-ray powder diffraction analysis (XRD) and scanning electron microscopy (SEM). Experimental results showed that the sample with the lowest impurity content was prepared by single-phase grinding for 120 min, followed by annealing at 1300 °C for 90 minutes.

The ability of building material surfaces to clean themselves significantly lowers long-term maintenance costs of structures. Self-cleaning behaviour can arise from hydrophobicity, photocatalysis, or their combination. This study concentrates on the photocatalytic route. We prepared white cement paste specimens whose surfaces were coated with carbon-doped g-C₃N₄. Carbon doping was chosen because it narrows the band gap of g-C₃N₄ and improves the separation of photogenerated charge carriers, thereby increasing photocatalytic activity under visible light. The self-cleaning efficiency of the modified surfaces was assessed by two complementary standard methods: the Rhodamine B degradation test according to UNI 11259 and the measurement of water contact angle according to ČSN ISO 27448. Despite the different physical principles of the two techniques, both confirmed a marked self-cleaning effect of the carbon-doped g-C₃N₄ layers. Moreover, the contact-angle results supported the applicability of the Rhodamine B method even for the light-yellowish coatings typical of these materials.
ACKNOWLEDGEMENT: This research was supported by the Czech Science Foundation under the project 24-10949S, while the infrastructure has been utilized in the frame of project No. CZ.02.01.01/00/22_008/0004631 Materials and technologies for sustainable development within the Jan Amos Komensky Operational Program financed by the European Union and from the state budget of the Czech Republic.

Metal-organic frameworks (MOFs) have attracted considerable attention as adsorbents because of their high porosity and tunable chemistry. In this study, we examined how different material design strategies, including metal-node substitution, composite formation, synthesis route, and post-adsorption processing, influence framework structural stability under realistic groundwater conditions.
A series of ZIF-8- and UiO-66-nanoparticle-based materials was evaluated before and after exposure to naturally contaminated groundwater. The results showed that Ni-substituted ZIF-8 sample retained its crystalline structure better than pristine ZIF-8, despite the low level of Ni incorporation. Similarly, GAC-supported ZIF-8 composites synthesized in methanol preserved their crystallinity after adsorption, whereas PVA-based composites underwent pronounced structural degradation. For UiO-66, the post-adsorption drying procedure also proved important, with gradual drying at room temperature preserving the framework more effectively than oven drying.
Despite these differences in structural stability, the selected MOF materials maintained high adsorption efficiencies toward both radionuclides (Lu and Tb) and oxoanions (arsenate and phosphate), exceeding 90% in all cases. Presented results show that framework stability is determined not only by the intrinsic chemistry of the MOF but also by the way the material is synthesized, processed, and integrated into composite systems. The study highlights the importance of considering structural stability alongside adsorption performance when designing MOF-based adsorbents for operation in realistic aqueous environments.
ACKNOWLEDGEMENT: This research was supported by the Science Fund of the Republic of Serbia, Grant No. 7282, Project title "Design of radioactive magnetic nanoconstructs for tumour therapy by synergy of nanobrachytherapy and magnetic hyperthermia" - RADIOMAG.

The occurrence of endocrine-disrupting compounds in aquatic environments has become a growing environmental concern due to their persistence and biological activity at trace concentrations. Among these contaminants, ethinylestradiol (EE2), a synthetic estrogen widely used in oral contraceptives, poses a significant risk to aquatic organisms and water quality [1]. In this work, porous carbon adsorbents for EE2 removal from aquatic environment were prepared from renewable microcrystalline cellulose using an ice-templating approach followed by carbonization [2].
To enhance pore development, a ferrous salt was incorporated into the cellulose suspension prior to freeze-casting. During subsequent thermal treatment, iron-containing nanoparticles were formed within the carbon matrix. These nanoparticles acted as sacrificial templates and were subsequently removed by leaching with diluted hydrochloric acid followed by washing with demineralized water, resulting in increased porosity and surface accessibility of the carbon material. Moreover, acid leaching wash away any species that could be released into aqueous environment during EE2 adsorption.
The prepared porous carbons were characterized in terms of their morphology, textural properties, and chemical composition. The influence of iron-assisted templating and acid leaching on pore formation was evaluated. The adsorption performance of the materials toward ethinylestradiol in aqueous solutions was investigated to assess their potential for water treatment applications.
The results demonstrate that the combination of ice-templating and iron-assisted pore generation provides an effective route for producing highly porous carbon materials from sustainable biomass precursors. The developed adsorbents show promise for the removal of endocrine-disrupting pollutants from water and contribute to the development of environmentally friendly remediation technologies.
[1] N. Leroux, S. Baekelandt, J.-B. Robert, L. Burattin, C. Keime, C. Gérard, P. Kestemont: Assessment of the effects of estetrol and 17α-ethinylestradiol on zebrafish (Danio rerio) metamorphosis: a morphological and transcriptomic approach. Environmental Pollution 376 (2025) 126423
[2] M. P. Chavhan, A. Kryeziu, S. Ganguly, J. Parmentier: Monolithic metal-based/porous carbon nanocomposites made from dissolved cellulose for use in electrochemical capacitor. Green Carbon 2 (2024) 109-117.

Robust and earth-abundant electrocatalysts based on earth-abundant elements are essential for advancing alkaline water electrolysis. In this work, ozone-assisted Atomic Layer Deposition (ALD) was employed to synthesize NiOₓ, CoOₓ, and mixed NiCoOₓ thin films for bifunctional electrocatalytic water splitting applications. Using nickelocene and cobaltocene precursors with ozone as oxidant, conformal coatings were deposited on planar substrates as well as three-dimensional nickel foam (NF) and stainless-steel (SS) mesh electrodes.
The influence of catalyst composition and substrate architecture on electrochemical performance was investigated in 1.0 M KOH. Mixed NiCoOₓ coatings deposited on SS mesh exhibited enhanced oxygen evolution reaction (OER) activity, achieving an overpotential of 310 mV at 10 mA cm⁻² and a Tafel slope of 46 mV dec⁻¹. In contrast, deposition on NF promoted hydrogen evolution reaction (HER) performance, showing a low onset overpotential of 230 mV together with improved charge-transfer kinetics.
These results demonstrate the potential of ozone-based ALD for the controlled fabrication of conformal mixed-metal oxide electrocatalysts on complex 3D substrates and highlight the role of substrate engineering in tuning bifunctional catalytic activity for alkaline water electrolysis.
ACKNOWLEDGEMENTS: This work was supported by MUR under FISA-2024-00112 “H2GreenCoat - Hybrid Coating Technologies to Produce Green Hydrogen by Water Electrolysis”, granted by Decree prot. n. 18365 of 20 November 2025 (CUP: D73C25001300001; D33C25001000001)
REFERENCES: [1] K. A. Jannath and H. A. Saputra, “Transition metal-based electrocatalysts for alkaline oxygen evolution reaction: Developments, challenges, and perspectives,” Next Materials, vol. 9, no. 5, p. 101164, Oct. 2025; [2] R. T. M. van Limpt, M. Lavorenti, M. A. Verheijen, M. N. Tsampas, and M. Creatore, “Control by atomic layer deposition over the chemical composition of nickel cobalt oxide for the oxygen evolution reaction,” Journal of Vacuum Science & Technology A, vol. 41, no. 3, May 2023.

Water source pollution poses an ecological and health problem, necessitating the development of new and effective filtration materials. This study focuses on the fabrication, plasma modification, and characterization of composite membranes based on polymeric nanofibers and plasma-reduced graphene oxide (rGO) for the removal of various water contaminants. Polyamide (PA6) nanofibers were deposited onto a DCSBD plasma-pretreated polypropylene non-woven fabric using electrospinning. The rGO was fabricated by atmospheric-pressure DCSBD plasma-triggered reduction of graphene oxide (GO) papers in a nitrogen atmosphere, followed by nitrogen plasma functionalization using a DCSBD linear APPJ to enhance its adsorption capabilities. The prepared materials were assembled into three types of membranes: PA6 nanofibers without rGO, rGO-containing membranes, and membranes containing nitrogen-functionalized rGO (N-rGO) which were subsequently tested for filtration of selected organic and heavy metals pollutants.
Filtration efficiency was evaluated using UV-Vis spectrophotometry, HPLC-MS, and ICP-MS. The results demonstrated higher pollutant removal efficiency for rGO-based membranes compared with nanofiber-only membranes. N-functionalization (amines and amides together with formation of oxygen functionalities) further enhanced pollutant removal under selected conditions; however, its effect depended on the specific pollutant and solution pH. Separate adsorption experiments with rGO were also performed at different pH values. The results confirmed the ability of rGO to adsorb the tested pollutants depending on pollutant type and solution pH. The observed trends were consistent with the filtration results, indicating a significant contribution of rGO adsorption to the overall pollutant removal process.

Soils are known by their self-cleaning ability based on the complexation of organic matter with different pollutants and “locking” of them in the matter. Key constituents of soil organic matter are humic substances which are (due to their unique structure) able to immobilize different pollutants in stable complexes resulted in a reduced leachability in soil solution and their input into surface and ground water and plant uptake. These properties of humic substances can be utilized not only in soil systems but also e.g. for water cleaning or waste treatment. In the last decades, pharmaceuticals have been extensively used in large quantities which resulted in their input in environmental systems from their production, industries, hospitals and households, wastewater used in irrigation, and sewage sludges from municipal wastewater treatment plants. In this contribution, sulfathiazole and tetracycline as representants of widely used antibiotics which can be found in ecosystems. The paper deals with the complexation ability of humic substance for these antibiotics and their leachability (chemical stability) connected with their bio-availability and biotoxicity. Simultaneously, obtained results will served as a background for the humic application as the aid for a keeping of health environmental systems. The stability of formed complexes were assessed also by means thermogravimetry where parameters of thermal decomposition will be correlated with antibiotic leachability and potential relation-ships between chemical and thermal stabilities were investigated and discussed.

Antibiotic residues persistently contaminate aquatic environments, posing significant ecological and public health risks. This study presents the development of innovative hybrid materials combining natural polysaccharides with inorganic clay fillers, demonstrating high surface activity and functional versatility for the simultaneous specific adsorption of pharmaceutical residues from polluted waters.
Using natural polysaccharides such as chitosan, alginate, and agarose was obtained a stable three-dimensional hydrogel with high water-retention capacity (>90%) and tunable porosity. Incorporation of mineral clay such as Montmorillonites and Laponite, enhanced the mechanical stability, specific surface area, and density of active adsorption sites. The nanostructured hydrogels exhibited strong affinity toward antibiotics such as tetracycline, ciprofloxacin and sulfadimethoxin, through multiple interaction mechanisms, including electrostatic attraction, hydrogen bonding, and π-π interactions between the antibiotic molecules and the functional groups present in the polymer-clay network.
Physicochemical characterization demonstrated adsorption capacities ranging from 100 to 450 mg/g for tetracycline, 80-250 mg/g for ciprofloxacin and 50-180 mg/g for sulfadimethoxine, depending on the crosslinking degree and functionalization strategy, while removal efficiencies reached up to 85% under optimized pH and adsorbent dosage conditions. Adsorption kinetics followed a pseudo-second-order model, indicating chemisorption as the dominant mechanism. The synergistic combination of biopolymers and inorganic nanomaterials provides promising hybrid matrices for environmental decontamination.
ACKNOWLEDGMENTS: This work was carried out through the PN 23.06 Core Program - ChemNewDeal, project no. PN 23.06.01.01-AQUAMAT, and within CCCDI - UEFISCDI, project no. PN-IV-P7-7.1-PED-2024-1277-SafeBioChain.

Biochar is a porous, carbon-rich material that can be used as a soil amendment improving soil properties. However, the high temperatures used during pyrolysis produce a sterile material with a limited impact on soil biological processes. Therefore, this study evaluated the feasibility of enriching biochar with plant growth-promoting rhizobacteria (PGPR) to develop a biologically active product with potential applications in sustainable agriculture.
Four commercial biochar samples (Carbohran, Novocarbo, Bio-Pflanzenkohle, and Zera) and the bacterial strain Azotobacter vinelandii CCM 289 were used in this study. The materials were characterized in terms of their organic and inorganic content (TGA), inorganic elemental composition of aqueous extracts (ICP-OES), and physicochemical properties (pH and electrical conductivity). Two biochar colonization approaches (post-cultivation and co-cultivation) were compared, while bacterial viability was assessed by flow cytometry. The hydrogel samples were rheologically characterized and subsequently freeze-dried to obtain a stable and easily handled material.
The experimental part of the study was based on a 92-day pot experiment with maize (Zea mays), in which freeze-dried PGPR carriers were applied to soil. After the cultivation experiment, plant growth parameters (plant height, biomass, and ear number) as well as soil physicochemical and microbiological properties were evaluated. Microbial properties were assessed using cultivation-based assays and BIOLOG EcoPlate™ analysis, while PGP activity was evaluated.
The results showed that the combination of biochar and PGPR supported microbial activity, contributed to soil pH stabilization, and demonstrated the potential of biochar as a carrier containing beneficial microorganisms. These findings may support the development of environmentally friendly biofertilizers.

Soil respiration is a key indicator of soil quality and the soil microbial activity, and it plays a significant role in the global carbon cycle. The rates of carbon dioxide release and oxygen consumption depend on organic matter availability, soil structure, and environmental conditions, particularly temperature and moisture.
This study focuses on optimizing respirometric measurements using the OxiTop®-IDS system, evaluating the effect of selected experimental conditions (temperature, soil moisture) and the application of bioinoculants containing plant-growth-promoting rhizobacteria (PGPR) on soil respiration rate. The rhizobacterial strain Azotobacter vinelandii CCM 289 was used to prepare all application forms of the bioinoculants (bacterial culture in PBS, alginate gel with presence and absence of bacterial culture and biochar, and freeze-dried equivalent of previous bioinoculants).
The results confirmed that soil respiration is strongly influenced by changes in temperature and soil moisture. All applied soil conditioners led to a significant increase in the respiration rate of the used model soil. The OxiTop®-IDS system demonstrated high reliability and sensitivity in monitoring microbial activity in soil. These findings indicate that soil respiration using this method provide a suitable and effective tool for assessing the soil functional state as well as for evaluating the effectiveness of soil amendments.
This work was supported by the Czech Science Foundation of the Czech Republic (grant number: GA23-06757S) and NATO Science for Peace and Security Programme (project Nr. G6296).

The presence of pesticide residues in water is an important environmental concern, motivating the development of efficient materials for their removal. In this work, electrospun functional nanofibers were developed for the removal of pesticide contaminants from aqueous media by combining magnetite (Fe₃O₄) nanoparticles with β-cyclodextrin (β-CD) in a poly(vinyl alcohol) (PVA)-based fibrous matrix. The material design combines magnetic functionality with the ability of β-CD to interact with organic molecules, aiming to develop a multifunctional material for environmental remediation.
A core-shell architecture was investigated, consisting of a Fe₃O₄-containing PVA core and a PVA/β-CD-based shell. Citric acid was incorporated into the polymeric formulation to improve the aqueous stability of the PVA-based material after thermal treatment. The influence of solution composition and electrospinning conditions on fiber formation was investigated, and the resulting materials were characterized by electron microscopy and magnetic measurements.
The materials were evaluated for the removal of selected pesticides from aqueous media, including linuron and pirimethanil. Preliminary experiments showed removal efficiencies of approximately 75% for linuron and 65% for pirimethanil. These results highlight the potential of electrospun nanofibrous materials combining Fe₃O₄ nanoparticles and β-CD as multifunctional materials for the removal of organic contaminants from water and for environmental remediation applications.