Search Results (194)

This study presented the successful synthesis of a visible light responsive Z-scheme BiTmDySbO₇/BiEuO₃ heterojunction photocatalyst (BBHP) via the hydrothermal method, exhibiting outstanding removal efficiency for degrading the metronidazole (MNZ) in wastewater. The BBHP exhibited exceptional photocatalytic activity during the degradation process of the MNZ which was a widely detected pharmaceutical pollutant in aquatic environments. The key to the high photocatalytic activity of the BBHP was the formation of a Z-scheme photogenerated carrier transport channel which existed between BiTmDySbO₇ and BiEuO₃ within the heterojunction structure. This innovative structural design was experimentally confirmed for enhancing the separation efficiency of the photogenerated charge carriers significantly, thereby, the efficient photocatalytic activity of the BBHP was promoted. After visible light irradiation for 130 min, the BBHP achieved a removal efficiency of 99.56% for degrading MNZ and a mineralization rate of 98.11% for removing the total organic carbon (TOC) concentration. In contrast to a single photocatalyst, the removal rate of the MNZ by using the BBHP was 1.14 times that by using the BiEuO₃, 1.26 times that by using the BiTmDySbO₇, and 2.65 times that by using the nitrogen-doped TiO₂ (N-T) under visible light irradiation. The mineralization rate for removing the TOC concentration during the degradation process of the MNZ by using the BBHP was 1.17 times that by using the BiEuO₃, 1.29 times that by using the BiTmDySbO₇, and 2.86 times that by using the N-T under visible light irradiation. The photocatalytic degradation process of the MNZ by using the BBHP followed first-order kinetics model, concurrently, a dynamics rate constant of 0.0345 min⁻¹ was obtained. Furthermore, the BBHP demonstrated excellent stability and durability in accordance with multiple cyclic degradation experiments. According to the capturing radicals experiments and the electron paramagnetic resonance test experiments, it was determined that the hydroxyl radicals (•OH) and the superoxide anions (•O₂⁻) played key role during the photocatalytic degradation process of the MNZ by using the BBHP under visible light irradiation. Finally, the intermediate products that were produced during the degradation process of the MNZ were analyzed by using liquid chromatography-mass spectrometer, as a result, a potential degradation pathway for the MNZ was proposed. Overall, this study could provide valuable references for future research on composite photocatalysts and effectively maintain the safety and sustainable utilization of water resource. Full article

The persistent release of synthetic dyes such as methylene blue (MB) into aquatic environments poses a significant ecological hazard due to their chemical stability and toxicity. In recent years, the application of engineered composite photocatalysts has emerged as a potent solution for efficient dye degradation under visible and UV light. This review comprehensively summarizes various advanced composites, including carbon-based, metal-doped, and heterojunction materials, tailored for MB degradation. Notably, composites such as TiO₂/C-550, WS₂/GO/Au, and MOF-derived α-Fe₂O₃/ZnO achieved near-complete degradation (>99%) within 30–150 min, while others, like ZnO/JSAC-COO⁻ and Ag/TiO₂/CNT, displayed enhanced charge separation and stability over five consecutive cycles. Band gap engineering (ranging from 1.7 eV to 3.2 eV) and reactive oxygen species (·OH, ·O₂⁻) generation were key to their photocatalytic performance. This review compares the structural attributes, synthetic strategies, and degradation kinetics across systems, highlighting the synergistic role of co-catalysts, surface area, and electron mobility. This work offers systematic insight into the state-of-the-art composite photocatalysts and provides a comparative framework to guide future material design for wastewater treatment applications. Full article

High-temperature proton exchange membrane fuel cells (HT-PEMFCs) offer distinct advantages over their low-temperature counterparts. However, their commercial viability is significantly hampered by durability challenges stemming from electrocatalyst support degradation in the corrosive phosphoric acid environment. This review provides a comprehensive analysis of advanced strategies to overcome this critical durability issue. Two main research directions are explored. The first involves engineering more robust carbon-based materials, including graphitized carbons, carbon nanostructures (nanotubes and graphene), and heteroatom-doped carbons, which enhance stability by modifying the carbon’s intrinsic structure and surface chemistry. The second direction focuses on replacing carbon entirely with intrinsically stable non-carbonaceous materials. These include metal oxides (e.g., TiO₂, SnO₂), transition metal carbides (e.g., WC, TiC), and nitrides (e.g., Nb₄N₅). For these non-carbon materials, a key focus is on overcoming their typically low electronic conductivity through strategies such as doping and the formation of multi-component composites. The analysis benchmarks the performance and durability of these advanced supports, concluding that rationally designed composite materials, which combine the strengths of different material classes, represent the most promising path toward developing next-generation, long-lasting catalysts for HT-PEMFCs. Full article

The transition to a sustainable chemical industry necessitates efficient valorization of biomass, with polyols serving as versatile, renewable feedstocks. This comprehensive review, focusing on advancements within the last five years, critically analyzes the selective hydrogenolysis of key biomass-derived polyols—including glycerol, erythritol, xylitol, and sorbitol—into valuable diols. Emphasis is placed on the intricate catalytic strategies developed to control C–O bond cleavage, preventing undesired C–C scission and cyclization. The review highlights the design of bifunctional catalysts, often integrating noble metals (e.g., Pt, Ru, Ir) with oxophilic promoters (e.g., Re, W, Sn) on tailored supports (e.g., TiO₂, Nb₂O₅, N-doped carbon), which have led to significant improvements in selectivity towards specific diols such as 1,2-propanediol (1,2-PD), 1,3-propanediol (1,3-PD), and ethylene glycol (EG). While substantial progress in mechanistic understanding and catalyst performance has been achieved, challenges persist regarding catalyst stability under harsh hydrothermal conditions, the economic viability of noble metal systems, and the processing of complex polyol mixtures from lignocellulosic hydrolysates. Future directions for this field underscore the imperative for more robust, cost-effective catalysts, advanced computational tools, and intensified process designs to facilitate industrial-scale production of bio-based diols. Full article

A high-performance Z-scheme heterojunction photocatalytic compound, ZnBiGdO₄/SnS₂ (ZS), was prepared for the first time using a microwave-assisted solvothermal method. ZS significantly improved the separation efficiency of photoinduced carriers and effectively broadened the response range to visible light through the unique mechanism of the Z-type heterojunction. Therefore, ZS exhibited an excellent photocatalytic performance during the degradation process of tinidazole (TNZ). Specifically, the removal rate of TNZ by ZS reached 99.63%, and the removal rate of total organic carbon (TOC) reached 98.37% with ZS as catalyst under visible light irradiation (VLIN). Compared to other photocatalysts, the photocatalytic performance of ZS was significantly better than that of ZnBiGdO₄, SnS₂, or N-doped TiO₂ (N-T). The removal rate of TNZ by ZS was 1.12 times, 1.26 times, or 2.41 times higher than that by ZnBiGdO₄, SnS₂, or N-T, respectively. The mineralization efficiency of TNZ for TOC with ZS as a catalyst was 1.15 times, 1.28 times, or 2.57 times higher than that with ZnBiGdO₄, SnS₂, or N-T as a catalyst, respectively. Free radical scavenging experiments and the electron paramagnetic resonance experiments confirmed that ZS could generate multiple reactive species such as hydroxyl radicals (•OH), superoxide anions (•O₂⁻), and photoinduced holes (h⁺) during the photocatalytic degradation process of TNZ. The photocatalytic degradation performance of ZS on TNZ under VLIN was evaluated, concurrently, the reliability, reproducibility, and stability of ZS were verified by five cycle experiments. This study explored the degradation mechanism and degradation pathway of TNZ with ZS as a catalyst under VLIN. This study not only provides new ideas for the design and preparation of Z-type heterojunction photocatalysts but also lays an important foundation for the development of efficient environmental remediation technologies for TNZ pollution. Full article

Severe polysulfide shuttling and sluggish redox kinetics critically hinder lithium–sulfur (Li-S) battery commercialization. In this study, a multifunctional diatomite (DE)/TiO₂/MoS₂/N-doped carbon nanofiber (NCNF) composite separator was fabricated via hydrothermal synthesis, electrospinning, and carbonization. DE provides dual polysulfide suppression, encompassing microporous confinement and electrostatic repulsion. By integrating synergistic catalytic effects from TiO₂ and MoS₂ nanoparticles, which accelerate polysulfide conversion, and conductive NCNF networks, which facilitate rapid charge transfer, this hierarchical design achieves exceptional electrochemical performance: a 1245.6 mAh g⁻¹ initial capacity at 0.5 C and 65.94% retention after 200 cycles. This work presents a rational multi-component engineering strategy to suppress shuttle effects in high-energy-density Li-S batteries. Full article

This study evaluates the efficiency of sub-stoichiometric Ti₄O₇ titanium oxide anodes for the electrochemical degradation of glyphosate, a persistent herbicide classified as a probable carcinogen by the World Health Organization. After optimizing the process operating parameters (pH and current density), the mineralization efficiency and fate of degradation by-products of the treated solution were determined using a total organic carbon (TOC) analyzer and HPLC/MS, respectively. The results showed that at pH = 3, glyphosate degradation and mineralization are enhanced by the increased generation of hydroxyl radicals (^●OH) at the anode surface. A current density of 14 ${\mathrm{mA} \mathrm{cm}}^{-2}$ enables complete glyphosate removal with 77.8% mineralization. Compared with boron-doped diamond (BDD), ${\mathrm{Ti}}_4{\mathrm{O}}_7$ shows close performance for treatment of a concentrated glyphosate solution (0.41 mM), obtained after nanofiltration of a synthetic ionic solution (0.1 mM glyphosate), carried out using an NF-270 membrane at a conversion rate (Y) of 80%. At 10${ \mathrm{mA} \mathrm{cm}}^{-2}$ for 8 h, ${\mathrm{Ti}}_4{\mathrm{O}}_7$ achieved 81.3% mineralization with an energy consumption of 6.09 ${\mathrm{kWh} \mathrm{g}}^{-1}$ TOC, compared with 90.5% for BDD at 5.48 ${\mathrm{kWh} \mathrm{g}}^{-1}$ TOC. Despite a slight yield gap, ${\mathrm{Ti}}_4{\mathrm{O}}_7$ demonstrates notable efficiency under demanding conditions, suggesting its potential as a cost-effective alternative to BDD for glyphosate electro-oxidation. Full article

For the efficient operation of various TiO₂-based devices, it is important to understand the patterns of electric charge transport. In the present paper TiO₂-C-Cu nanocomposites were synthesized by the electrochemical method. The band gap energy Eg of all systems was found to be approximately the same, 3.2 eV. Both copper ions replacing titanium ions and copper ions within the CuO phase were detected. The modification of TiO₂-C nanotubes by copper led to a significant increase in conductivity and photocurrent, which may be associated with the formation of new donor states (Ti³⁺ centers) creating levels in the band gap of TiO₂-C-Cu. The characteristics of charge carrier transport (including photocurrent) in TiO₂-C-Cu materials were revealed for the first time. The conductivity at DC and at low frequencies of AC is due to the movement of electrons along the conduction zone, whereas at high frequencies there is a hopping mechanism of conduction. The acquired original results testify to the potential usage of TiO₂-C-Cu nanocomposites in the field of catalysis and photoelectrochemistry. Full article

The contamination of aquatic ecosystems by the micropollutants in wastewater discharges is currently a critical issue. Therefore, the development of novel treatment processes and materials is essential to ensure the availability of safe water. The present study aims to develop a photocatalytic material composed of silver nanoparticles (Ag-NPs)-doped TiO₂ supported on a Pyrex^® plate (TiO₂@Ag-NPs) exhibiting catalytic activity under visible irradiation (λ > 400 nm). The effects of Ag-NPs doping on the TiO₂ matrix, the resistance of the coating at the catalyst/substrate interface, and the photocatalytic degradation efficiency of the photocatalyst for a micropollutant (diuron) of the pesticide family were studied. The photocatalyst was characterised using X-ray diffraction, scanning electron microscopy, ultraviolet–visible spectrophotometry, and scratch tests. The solution concentrations were monitored using high-performance liquid chromatography and total organic carbon analyses. A 32% diuron removal was achieved using photocatalytic TiO₂@Ag-NPs under visible irradiation, whereas undoped TiO₂ showed no activity. Furthermore, the effects of the nanoparticle growth mode on the photocatalytic activity of TiO₂@Ag-NPs were explored. The presence of a TiO₂ sublayer ensured the adhesion of the coating and promoted the dispersion of nanoparticles within the matrix. It ensured chemical continuity (TiO₂@Ag-NPs/Pyrex^®), reduced the bandgap, and decreased electron–hole pair recombination. Full article

Two-dimensional (2D) hexagonal boron carbon nitride (h-B_xC_yN_z) has garnered a lot of interest in the last two decades because of its remarkable physical and chemical characteristics. Because of the carbon atoms, it has a smaller gap than its cousin, boron nitride, and is hence more appropriate for a wider range of applications. In the frame of density functional theory, we discuss the structural, electronic, and magnetic properties of mono Ti-doped and Co-doped BC₆N (Ti/Co-BC₆N) at different sites of substitutional doping (Ti/Co) in the BC₆N monolayer. The mono substitutional doping at the B (Ti_B/Co_B), N (Ti_N/Co_N), and two different C (C1 (Ti_C1/Co_C1), C2 (Ti_C2/Co_C2)) sites, are investigated. The position of the Ti/Co dopant is an important parameter that changes the electronic state, magnetic moment, and adsorption activity of the pristine BC₆N nanosheet. We find that the adsorption of the gases NO, NO₂, CO₂, NH₃, N₂, and O₂ is significantly improved on the doped sheet at all doped positions compared to the adsorption on the pristine structure. The Ti/Co-BC₆N can adsorb NO and NO₂ better than CO₂ and NH₃. Ti_C1-BC₆N and Ti_B-BC₆N are the best doped sheets for adsorbing NO and NO₂, respectively. The CO₂ and the N₂ molecules are moderately adsorbed at all doped positions as compared to the other adsorbed molecules. Ti-doped sheets can adsorb the CO₂, NH₃, and O₂ better than the corresponding Co-doped sheets. We also study the adsorption of molecular hydrogen on our single-atom Ti/Co-doped systems, as well as on 4-atom Ti and Co clusters embedded in the BC₆N sheets. We show that the cluster-embedded sheets can adsorb up to four H₂ molecules. These novel findings are important for many applications of BC₆N, including spintronics, gas filtration, molecular sensing, and hydrogen storage. Full article

Na₄Fe₃(PO₄)₂P₂O₇ (NFPP) is recognized as a prospective electrode for sodium-ion batteries (SIBs) because of its structure stability, economic viability and environmental friendliness. Nevertheless, its commercialization is constrained by low operating voltage and limited theoretical capacity, which result in a power density significantly inferior to that of LiFePO₄. To address these limitations, in this work, we first designed and synthesized a series of Mn-doped NFPP to enhance its operating voltage, inspired by the successful design of LiFe_1-xMn_xPO₄ cathodes. This approach was implemented to enhance the operating voltage of the material. Subsequently, the optimized Na₄Fe_1.2Mn_1.8(PO₄)₂P₂O₇ (1.8Mn-NFMPP) sample was selected for further Ti-doped modification to enhance its cycle durability and rate performance. The final Mn/Ti co-doped Na₄Fe_1.2Mn_1.7Ti_0.1(PO₄)₂P₂O₇ (0.1Ti-NFMTPP) material exhibited a high operating voltage of ~3.6 V (vs. Na⁺/Na) in a half cell, with an outstanding reversible capacity of 122.9 mAh g⁻¹ at 0.1 C and remained at 90.6% capacity retention after 100 cycles at 0.5 C. When assembled into a coin-type full cell employing a commercial hard carbon anode, the optimized cathode material exhibited an initial capacity of 101.7 mAh g⁻¹, retaining 86.9% capacity retention over 50 cycles at 0.1 C. These results illustrated that optimal Mn/Ti co-doping is an effective methodology to boost the electrochemical behavior of NFPP materials, achieving mitigation of the Jahn–Teller effect on the Mn³⁺ and Mn dissolution problem, thereby significantly improving structural stability and cycling performance. Full article

The increasing presence of pharmaceutical contaminants, such as paracetamol, in water sources necessitates the development of efficient and sustainable treatment technologies. This study investigates the photocatalytic degradation and mineralization of paracetamol under visible light using nickel-doped titanium dioxide (Ni–TiO₂) catalysts synthesized via the sol-gel method. The catalysts were characterized through Raman spectroscopy, UV–Vis diffuse reflectance spectroscopy (UV–Vis DRS), and surface area measurements. Ni doping enhanced the visible light absorption of TiO₂, reducing its band gap from 3.11 eV (undoped) to 2.49 eV at 0.20 wt.% Ni loading, while Raman analysis confirmed Ni incorporation with anatase as the predominant phase. The Ni(0.1%)-TiO₂ catalyst exhibited the highest photocatalytic activity, achieving 88% total organic carbon (TOC) removal of paracetamol (5 ppm) after 180 min under optimal conditions (catalyst dosage, 3 g L⁻¹). Stability tests demonstrated 84% retained efficiency over five cycles, with a kinetic rate constant of 0.010 min⁻¹. Hydroxyl radicals were identified as the main reactive species. The catalyst maintained high performance in tap water, achieving 78.8% TOC removal. These findings highlight the potential of Ni(0.1%)-TiO₂ as a cost-effective, visible light-active photocatalyst for the removal of pharmaceutical pollutants, with promising scalability for industrial water treatment applications. Full article

As an environmentally friendly and clean energy technology, solar-driven interfacial evaporation technology has attracted wide attention. However, organic pollutants can easily pollute distilled water during the evaporation of wastewater. In this work, we report a strategy of N-TiO₂/C solar absorption with a low bandgap (2.33 eV), excellent light absorption ability, and high photothermal conversion efficiency (48.2%). Black N-TiO₂/C was prepared by the sol-gel method in the presence of hexamethylenetetramine as a source of nitrogen and carbon. The simultaneous N doping and C with superior photothermal effect rapidly increased the surface temperature of the material, reduced the recombination rate of electrons and holes, and improved the photocatalytic activity, showing great potential for solar thermal energy conversion. The prepared solar absorbent and polyurethane (PU) were mixed evenly to form a porous N-TiO₂/C/PU (NTCP) foam for purifying water. The evaporator produced clean water at a rate of 1.73 kg m⁻² h⁻¹ under the simulated sunlight of 1 sun irradiation. Meanwhile, the evaporator simultaneously photodegraded methylene blue (MB) and rhodamine B (RhB) underwater at a removal rate > 90%. The bifunctional solar water evaporation device combining photocatalytic and photothermal effects holds great potential for water purification. Full article

As a carbon-neutral and renewable raw material, cellulose can be transformed into biomass fuels to reduce the dependence on fossil fuels and carbon dioxide emissions. In view of harsh reaction conditions, low selectivity of product, and easy deactivation of the catalyst, this study studied the use of photothermal catalytic technology to convert cellulose into bio-oil rich in levulinic acid. It was discovered that a synergistic effect between heating and photocatalysis is present in cellulose degradation. Different metals were loaded on carbon nanotubes doped with titanium dioxide to prepare different photothermal catalysts, and their catalytic effects on cellulose were compared. It was found that TiO₂-CNT loaded with platinum metal exhibited the highest catalytic performance. By adopting Pt/TiO₂-CNT as the catalyst, the conversion rate of bio-oil reached 99.44%, and the selectivity of LA reached 44.41% at 220 °C for 3 h. As the photothermal catalysis increased the H/C ratio and decreased the O/C ratio of the liquid product, the calorific value reached 21.01 MJ/kg. This study can promote the further industrial application of lignocellulose to prepare fuel oil and decrease the environmental pollution caused by the massive consumption of fossil fuels. Full article

We report on the preparation and characterization of a cost-effective, durable, and reusable macrocomposite, prepared in the form of pellets and designed for the photodegradation of water pollutants, using amoxicillin (AMX) as a model compound. Using the wet impregnation method, kaolin clay and TiO₂-P25 composites were doped with copper (Cu²⁺) and cobalt (Co²⁺). The produced materials were characterized by SEM-EDS, XRD, XRF, textural property analysis, and their potential lixiviation of components by ICP-MS. The photodegradation efficiency under solar irradiation was evaluated by varying the acidity of the medium, the concentration of AMX, and the amount of catalyst. The performance of the recycled photocatalysts was also studied. The photodegradation of AMX was monitored by UV–Vis and UV–Vis/HPLC spectrophotometry. The optimal formulations, Cu (0.1%)/TiO₂ and Co (0.1%)/TiO₂, achieved up to 95% degradation of 5 mg·L⁻¹ AMX in 3 h at pH 5.9, with a catalyst loading of 1 g·L⁻¹. The Cu-doped material showed a slightly faster reaction rate and higher total-organic-carbon removal (80.4%) compared to the Co-doped material (59%) under identical conditions. The same photodegradation intermediates were identified by LC-MS/MS for both doped macrocomposites, and a reaction mechanism is proposed. These macrocomposites showed efficient and consistent recyclability over more than five reuse cycles, showing their potential to be used for antibiotic pollution abatement in water-treatment facilities. Full article