Search Results (6,893)

Photoelectrochemical (PEC) energy conversion is a promising approach for solar-to-chemical fuel production, but its practical performance is limited by insufficient visible-light utilization and charge-carrier recombination. Here, poly(3,4-ethylenedioxythiophene) (PEDOT)-centered TiO₂ hybrid electrodes were prepared by electropolymerizing PEDOT on FTO substrates, followed by electrochemical doping/dedoping treatment and coating with commercial TiO₂ as a model oxide semiconductor. SEM, EDS, and LIBS analyses confirmed the successful deposition of TiO₂ onto PEDOT-based films. Four-probe measurements showed that electrochemical doping reduced the apparent resistance of PEDOT-based electrodes, while UV–vis spectroscopy revealed enhanced long-wavelength absorption for doped PEDOT-containing films. PEC measurements using TiO₂, PEDOT, and TiO₂–PEDOT electrodes showed that PEDOT-containing electrodes exhibited much stronger photoresponses than commercial TiO₂ alone under both HER- and OER-relevant conditions. The TiO₂–PEDOT electrode showed stable photocurrent responses under chopped illumination and retained photoresponse under illumination transmitted through a 410 nm UV-cut filter, supporting the primary role of PEDOT in visible-light utilization. Long-term chronoamperometry further showed that TiO₂–PEDOT retained approximately 99.0% of its cathodic current under HER-relevant conditions and 91.9% of its anodic current under OER-relevant conditions after 5200 s of continuous illumination. The improved response of TiO₂–PEDOT compared with PEDOT alone suggests that TiO₂/PEDOT physical contact may assist interfacial charge separation and transport. These findings demonstrate that PEDOT-centered metal oxide/conducting polymer hybrids provide a useful model platform for visible-light-responsive PEC energy-conversion applications. Full article

The transition towards climate-neutral metallurgical production requires a broader transformation than the simple substitution of fossil-fuel combustion with electrical heating. While process electrification is a fundamental step towards reducing greenhouse gas emissions, achieving truly sustainable high-temperature processing also depends on the ability to maintain tightly controlled reaction environments, minimise thermal losses, and maximise the efficient use of process gases. These factors become increasingly important as the industry moves towards hydrogen-assisted processing routes and greater integration of renewable energy sources. By controlling heat transfer and gas composition, a stable processing environment can be maintained in which temperature, and gases’ partial pressure, can be accurately regulated throughout the treatment cycle. This study introduces the engineering concept of an airtight electrified indirect-fired rotary furnace, developed as a new process for efficient calcination, and also, hydrogen-based reduction processes. To assess the applicability of the proposed reactor concept, a bench-scale experimental campaign was carried out using two representative metallurgical processes: magnesite calcination and hydrogen-assisted reduction of lateritic ores. Throughout the testing campaign, the reactor maintained stable thermal conditions and a well-controlled process atmosphere, while the integrated monitoring system enabled continuous observation of temperature evolution and gas composition. The calcination trials achieved conversion efficiencies above 98%, whereas the hydrogen-reduction experiments successfully promoted the transformation of iron and nickel oxide phases into their metallic state. The results demonstrate that the integration of indirect electrical heating with airtight reactor operation provides a robust platform for hydrogen-assisted thermal processing. The proposed architecture improves atmosphere control and process efficiency while offering a scalable solution for the future implementation of electrified, low-carbon metallurgical technologies. Full article

The condensation reaction of pyromellitic dianhydride and (aminomethyl)phosphonic acid in imidazole yielded N,N′-bis(phosphonomethyl)pyromellitimide ([(H₂O₃P)CH₂-(C₁₀H₂N₂O₄)-CH₂(PO₃H₂)]∙2H₂O). Recrystallization of this compound from deionized water, by placing the solution in a desiccator to allow slow diffusion of HCl, afforded suitable single crystals for X-ray crystallographic studies. The compound crystallizes in the monoclinic space group P2₁/n. The flexible methylene phosphonic acid groups appended to both nitrogen termini adopt a trans configuration. The phosphonate and carbonyl groups (acceptors: P=O and C=O), together with water molecules [donor: O(6)—H∙∙∙O], participate in an extensive network of hydrogen-bonding interactions. Two of the phosphonate groups are protonated as P—OH (donors) and interact with oxygen atoms of neighboring phosphonate groups and water molecules. Hirshfeld surface analysis and associated two-dimensional fingerprint plots indicate that O∙∙∙H/H∙∙∙O (56.1%) contacts are the primary contributors to the crystal packing, followed by H∙∙∙H (16.3%) and C∙∙∙O/O∙∙∙C (13.4%) interactions. No significant π–π interactions were observed. The direct optical bandgap value, estimated from the Tauc plot, is 3.24 eV, indicating semiconducting behavior. The compound also exhibits thermal stability up to ~270 °C. These properties suggest that this compound may be a promising candidate for future investigation in organic electronic and optoelectronic materials. Full article

Ex situ hydrogen biomethanation represents a promising approach to converting surplus renewable electricity into CH₄-rich gas through the biological reduction in CO₂ with H₂, mediated by hydrogenotrophic methanogens. In this study, an ex situ H₂ biomethanation process was investigated in a lab-scale mesophilic anaerobic reactor operated in fed-batch mode. The system followed a cyclic operational strategy comprising sequential gas feeding, reaction, and discharge phases. Hydrogen was supplied through a pressure-controlled feeding strategy, whereas CO₂ injection maintained dissolved CO₂ concentrations at 25, 17, and 2 mg L⁻¹ during the initial, intermediate, and final stages, respectively. During early operation, volatile fatty acids (VFAs) temporarily accumulated to 3 g L⁻¹, accompanied by a decrease in pH. Progressively lowering the dissolved CO₂ target restored process stability, reduced the VFA concentration to 618 mg L⁻¹, and increased the pH to 7.6. Under stable final-stage conditions, the reactor achieved an average CH₄ concentration of 93.3%, a hydrogen utilization efficiency of 99%, and a methane evolution rate (MER) of 3.95 NL CH₄ L_VR⁻¹ d⁻¹. These results show that combining pressure-controlled hydrogen injection with dissolved CO₂ regulation enhances methane production and maintains stable ex situ biomethanation. Full article

Methane aromatization mainly proceeds at 650–750 °C. Simultaneous separation of hydrogen and oxygen can boost conversion efficiency and mitigate catalyst coking, yet most non-electrochemical membrane reactors fail to achieve synchronous hydrogen–oxygen separation within this temperature range. Accordingly, an electrochemical membrane reactor is adopted in this work, and steam is introduced to improve gas separation efficiency. BZCY hollow fiber membranes with mixed proton and oxygen ion conductivity are selected as the research material, and the influences of three distinct steam feeding modes (anode side only, cathode side only, simultaneous feeding on both sides) on H₂ and O₂ permeation and separation are systematically investigated. Experimental results reveal that steam humidification significantly enhances the permeation fluxes of hydrogen and oxygen. Notably, such promotional effect strongly depends on the steam feeding location. At 700 °C and 1.5 V, the hydrogen permeation flux increases to 1.469 mL⋅min⁻¹⋅cm⁻², in sharp contrast to 0.189 mL⋅min⁻¹⋅cm⁻² under dry atmosphere. Meanwhile, the oxygen permeation flux reaches 0.824 mL⋅min⁻¹⋅cm⁻² at 700 °C with steam, which is approximately four times that under dry conditions. This study verifies the intrinsic H₂ and O₂ permeation capability of electrochemical membrane reactors and the remarkable promotion effect originating from steam, facilitating further practical applications of such membrane reactors in methane aromatization. Full article

Reactive oxygen and nitrogen species (RONS) generated by medical gas plasmas are considered major mediators of plasma-induced biological effects. This includes the atmospheric pressure argon plasma jet kINPen routinely used in clinical applications. The jet’s biomedical action has been shown to be tailored by modifying its feed gas. However, a systematic comparison of how feed gas composition and humidity shape plasma chemistry remains lacking, which would shift application-specific plasma chemistries from guessing to designing. In this study, we systematically investigated, compared, and statistically related 65 individual feed gas conditions of the kINPen argon plasma jet by increasing O₂, N₂, and combined O₂ + N₂ admixtures under dry and humidified conditions. Plasma gas phases were assessed using optical emission spectroscopy and reactive species produced in liquid via hydrogen peroxide, nitrite, and nitrate quantification. O₂-containing admixtures generally reduced overall plasma emission and liquid-phase RONS accumulation, whereas N₂-containing admixtures preferentially enhanced nitrogen-associated emission features. Water vapor addition via the admixture gas stream acted as an important secondary tuning parameter, exerting the strongest effects under combined O₂ + N₂ conditions. Multivariate analyses confirmed clear separation of chemistry profiles according to feed gas composition and humidity, while correlation and regression analyses identified several condition-dependent relationships between gas-phase emissions and liquid-phase reaction products. These data provide a comprehensive characterization of kINPen plasma chemistry under controlled feed gas modification and establish a reference framework for tailoring plasma-derived reactive species profiles in future plasma biology and medicine studies. Full article

Considering the various applications where detection is required—whether for industrial or medical purposes—providing cost-efficient, stable, and highly selective solutions remains challenging. Different industries require hydrogen detectors, because this gas has the potential to serve as a clean and versatile energy carrier; therefore, precise monitoring and feedback in such systems are of enormous importance. Simultaneously, the medical field is developing new therapeutic methods using hydrogen as a medical gas, while also utilizing it as a biomarker in exhaled breath for various gastric diseases. In this paper, a ZnO-based gas sensor, doped with Ag nanoparticles produced via the Solution Chemical Synthesis (SCS) method, was coated with a thin polymer film of poly(1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane) PV4D4 via initiated Chemical Vapor Deposition (iCVD). The results are promising: at a relatively high operating temperature of 350 °C, the sensor showed its highest registered response to H₂ gas (up to 23%). Compared to other gases studied at the same temperature, the sensor also showed potential for detecting 2-propanol, n-butanol, and ethanol, albeit with lower responses. Based on the dynamic response analysis, the fastest reaction time was also recorded at the highest operating temperature, thus showing versatile possibilities for using the specified detector. Full article

Sarcopenia, characterized by loss of muscle mass and strength, causes difficulty in standing and walking and increases fracture risk in older adults, making its prevention a priority for healthy aging. Whey protein isolate (WPI) promotes muscle protein synthesis, while ellagic acid (EA), a polyphenol, alleviates symptoms by reducing oxidative stress. However, WPI is prone to oxidative damage during processing, and EA suffers from low stability and bioaccessibility. For these reasons, a non-covalent complex was prepared from WPI and EA, and its preparation conditions were systematically optimized through single-factor experiments followed by orthogonal design. The objectives were to enhance the stability and bioaccessibility of EA through the protective effect of WPI, thereby enabling synergistic anti-sarcopenia effects. Multi-spectroscopic techniques and molecular simulations were employed for morphological characterization and interaction analysis. The optimal preparation conditions were pH 5.0, a 2 h reaction, and a WPI: EA molar ratio of 1:2.5. Under these conditions, the antioxidant activity of the WPI-EA non-covalent complex increased by 27.20% (p < 0.05). At the same time, protein digestibility decreased by 3.04% (p < 0.05). EA bound non-covalently near the tryptophan and tyrosine residues of WPI, altering its secondary and tertiary structures. WPI-EA non-covalent complex exhibited a 38.94% reduction in its surface hydrophobicity (p < 0.05) and a 2.42% increase in α-helix content (p < 0.05). These conformational changes provided a structural basis for the improved bioaccessibility of WPI. The spectroscopic observations were corroborated by molecular docking and MD simulations, which revealed that both hydrophobic interactions and hydrogen bonds contributed to the stable binding of EA to β-Lg, with hydrophobic contacts predominating in the binding mode and hydrogen bonds playing a critical role in maintaining conformational stability throughout the simulation. In summary, the WPI-EA non-covalent complex exhibited good antioxidant activity, indicating its potential as a functional ingredient for sarcopenia management and for improving skeletal muscle health in aging individuals. Full article

This study investigates the influence of a non-ionic deep eutectic solvent on a cobalt-catalyzed C—H activation reaction. In this context, we demonstrate the feasibility of a cobalt-catalyzed one-step activation of Csp²—H and N—H bonds in benzosulfonamides, directed by aminoquinoline, with symmetrical 1,3-diynes for the synthesis of benzosultams. Rather than serving solely as a solvent replacement, the non-ionic deep eutectic solvent acts as a structured hydrogen-bonding reaction medium compatible with cobalt-catalyzed C—H activation. The study demonstrates that cobalt-catalyzed C—H activation can proceed with substrate-dependent product selectivity under these conditions, although further optimization is required to improve conversion and catalytic efficiency. These findings provide initial insights into solvent effects on cobalt-catalyzed C—H activation under non-conventional reaction media. Full article

Combined cooling, heating, and power (CCHP) tri-generation systems can greatly improve comprehensive energy utilization efficiency thanks to their energy-cascade utilization concept. However, traditional fossil-fuel-based CCHP systems still suffer from intensive carbon emissions, hindering their further development in the current low-carbon scenario. To solve this issue, a new low-carbon CCHP system (LC-CCHP) integrating a calcium-looping, sorption-enhanced steam methane reforming (CL-SE-SMR) unit, a lithium bromide absorption chiller, and a hydrogen gas turbine is proposed in this work, and the corresponding system model is built to evaluate its performance. The proposed system features an innovative architecture that integrates carbon capture directly into the reforming process, which simultaneously enables a high hydrogen yield and low carbon-capture penalty. Moreover, instead of the widely used thermodynamic equilibrium assumption, a detailed kinetic model is employed for the CL-SE-SMR unit, which provides more realistic predictions and greater reference value for practical engineering applications. Then, multi-objective optimization is conducted using a particle swarm optimization algorithm to identify the optimal operating conditions. It is found that the proposed system performs best at a steam-to-carbon molar ratio of 4.37, a calcium-to-carbon mass ratio of 6.23, an air-equivalency molar ratio of 1.39 for a hydrogen gas turbine and a reaction temperature of 600 °C for SE-SMR. Under these operating conditions, the system can achieve a carbon-capture rate of 89.2%, an exergy efficiency of 45.7%, an energy efficiency of 95.4%, and a levelized cost of exergy of 0.109 $/kWh. Full article

Oxidative desulfurization (ODS) is a promising alternative to conventional desulfurization methods because it operates under relatively mild conditions. Mixing-assisted oxidative desulfurization (MAOD), a variant of ODS, uses high-shear mixing to improve mass transfer between immiscible phases, enhancing sulfur conversion efficiency. This study reviews recent developments in MAOD for the removal of dibenzothiophene (DBT) and benzothiophene (BT) through a research matrix synthesizing the current literature. MAOD has demonstrated excellent performance, achieving up to 100% sulfur conversion in both model and real fuels, with DBT consistently showing higher conversion than BT. Response Surface Methodology (RSM) was commonly applied for process optimization, identifying typical operating conditions of 40–70 °C, 30 min reaction time, and 10,000 rpm as sufficient for complete sulfur conversion. The choice of oxidant and catalyst system strongly influences process efficiency, with polyoxometalates and hydrogen peroxide frequently achieving 100% conversion. Sustainable oxidants, including Fe(VI) and Mn(IV) derived from wastewater treatment sludge, have also shown promising results. However, the inability of model fuels to fully represent real fuel complexity and the limited use of RSM designs beyond Box–Behnken and Face-Centered Central Composite Designs highlight areas for future research. Overall, MAOD is a developing but highly promising desulfurization technology. Full article

Singlet oxygen is produced by light-dependent excitation of molecular oxygen using photosensitizers. Using blue light and riboflavin (RF) or riboflavin phosphate (RFP) as photosensitizers, we studied the reaction of singlet oxygen with tertiary amines in aqueous solution because many are used as biochemical buffers and as electron donors in photoreduction reactions. The reactions of singlet oxygen with multiple tertiary amines, including ethylenediamine tetraacetic acid (EDTA), bicine, and triethanolamine (TEOA), produced micromolar hydrogen peroxide (H₂O₂) as the stable end product. For bicine and TEOA, but not EDTA, H₂O₂ yield increased as pH increased due to their higher amine pKa values. A white LED used in conjunction with riboflavin and tertiary amines also produced H₂O₂, a contaminant likely to form during tissue culture manipulations. Direct photoreduction of 2,6-dichlorophenolindophenol and 2,3-dimethoxy-5-methyl-p-benzoquinone was achieved using blue light, RF or RFP, and tertiary amines as electron donors. With RF, EDTA was the optimal electron donor for both substrates, whereas with RFP, bicine and TEOA were superior to EDTA. Photochemical redox cycling of both quinones produced H₂O₂ via singlet oxygen-dependent re-oxidation of reduced quinols. Several amine buffers, including HEPES and PIPES, reacted with singlet oxygen to produce H₂O₂ but did not function as electron donors in quinone photoreduction assays. Full article

The development of efficient visible-light-driven semiconductor photocatalysts is essential for scalable and sustainable green hydrogen production. Among ternary metal oxides, MV₂O₆ (M = Zn, Ni, Cu, Mn, Co, etc.) metavanadates have attracted considerable interest because of their narrow band gaps (~1.8–2.5 eV), strong visible-light absorption, and unique edge-sharing VO₆ octahedral framework that promotes charge separation. This review summarizes recent advances in the design, synthesis, and electronic engineering of MV₂O₆-based photocatalysts for solar water splitting. Since direct particulate overall water splitting has only been demonstrated for MnV₂O₆, whereas ZnV₂O₆, NiV₂O₆, and CuV₂O₆ have mainly been investigated as photoelectrodes, both particulate photocatalytic and photoelectrochemical (PEC) systems are critically examined. The review clearly distinguishes these two configurations, highlighting how PEC studies provide valuable insights into charge transport, interfacial processes, and reaction kinetics while recognizing the additional challenges associated with suspension-based photocatalysis. Fundamental crystal structures, electronic band alignments, and charge-transfer characteristics of MV₂O₆ compounds are discussed, followed by recent advances in synthesis strategies, including hydrothermal, sol–gel, and deep eutectic solvent (DES)-assisted methods, together with morphology and defect engineering. Particular attention is given to oxygen-vacancy formation and its influence on visible-light absorption and charge separation. Modification strategies, including elemental doping, cocatalyst loading, and the construction of Z-scheme and step-scheme (S-scheme) heterojunctions, are critically evaluated for improving photocatalytic efficiency. Finally, the review discusses the key challenges that limit practical applications, including unfavorable band-edge positions, rapid carrier recombination, sluggish surface reaction kinetics, photostability, and the need to establish composition–structure–activity relationships. Future perspectives emphasize rational materials design through advanced characterization, theoretical calculations, and scalable synthesis approaches to accelerate the development of efficient MV₂O₆ photocatalysts for solar-driven hydrogen production. Full article

The development of efficient electrocatalysts for hydrogen generation is crucial for advancing clean and renewable energy technologies, yet the cooperative behavior governing dual-atom catalytic sites remains poorly clarified. In this study, an anti-sandwich dual-atom architecture supported on a BC₃ monolayer is examined through comprehensive first-principles modeling. By jointly assessing hydrogen adsorption thermodynamics, metal anchoring strength, and dynamic stability under elevated-temperature ab initio molecular dynamics conditions, two structurally resilient configurations with nearly ideal hydrogen binding characteristics are identified. Detailed orbital-resolved electronic analyses, incorporating projected electronic states, bonding population evaluation, and charge redistribution visualization, indicate that hydrogen adsorption and reaction activity are predominantly controlled by interatomic electronic coupling and orbital hybridization within the dual-atom centers. These insights reveal the electronic essence of dual-atom synergy and establish a transferable design principle for developing high-efficiency anti-sandwich catalysts for hydrogen evolution. Full article

This study addresses the urgent issue of nitrate-contaminated water by investigating Ni-Pt and Co-Pt catalysts supported on TiO₂, with the aim of improving both photocatalytic efficiency and reaction selectivity. The influence of adding non-noble metal co-catalysts to TiO₂, in addition to Pt, was explored. The synthesized samples were characterized by scanning electron microscopy (SEM), powder X-ray diffraction (XRD), hydrogen temperature-programmed reduction (H₂-TPR), diffuse reflectance UV–Vis spectroscopy, photoluminescence (PL), and X-ray photoelectron spectroscopy (XPS). The assessment of catalytic performance was conducted during the catalytic hydrogenation of nitrate, followed by an evaluation of the photocatalytic performance achieved when the aqueous nitrate solution was irradiated with UV light. The focus is on assessing the synergistic effects of the catalysts supported on TiO₂ in nitrate reduction, as well as their selectivity towards benign reaction products during the photocatalytic process, in contrast to the reactions occurring in the absence of light. Despite the selectivity for nitrite being preserved, the photocatalytic experiments indicated that the selectivity for N₂ reached around 68%, which is about 1.5 times higher than the values observed during the dark catalytic reaction. In contrast, the selectivity for ammonium saw a notable reduction. The findings were discussed in relation to the characteristics of the synthesized materials. Full article