Photocatalytic Ability Research Articles

Polarized electric field-mediated graphitic carbon nitride-based S-scheme heterostructure for efficient photocatalytic removal of bisphenol A

Tuning interface charge transfer is considered as a feasible way to promote electron migration and separation in heterojunction system, but the role of in-plane electron behavior in single phase has received little attention. Here, a carboxyl functionalized graphitic carbon nitride (CCN) coupled PbBiO2Br (PBOB) S-scheme heterostructure is elaborately designed for investigation. Compared with pristine CN/PBOB, although the existence of carboxyl group weakens the built-in electric field strength of CCN/PBOB (ΔΦ = 0.44 eV), the formed polarized electric field (µ = 3.18 Debye) is conducive to the pre-separation of photogenerated electrons and holes in CCN, thereby improving interface charge transfer. In addition, the introduced carboxyl group can also serve as an O2 adsorption site to enhance its activation, and generate reactive oxygen species (ROS) through a two-step single-electron O2 reduction route. Thus, the optimized CCN/PBOB exhibits excellent photocatalytic ROS generation ability, which can remove 88.7 % of bisphenol A and significantly reduce the acute toxicity of the formed intermediates. This work provides a new perspective for the development of advanced heterojunction photocatalyst by regulating in-plane/interface charge dynamics, and helps to fully understand the pollutant detoxification/degradation process initiated by molecular oxygen activation.

Hyaluronic acid modified prussian blue analogs/TiO₂ janus nanostructures through efficient charge separation to enhance photocatalytic-driven dual gas for achieve multimodal treatment of rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by the abnormal proliferation of fibroblast-like synoviocytes and changes in the joint synovium, including elevated reactive oxygen species, decreased pH, and reduced oxygen content. In this study, we synthesized a novel nanocomposite material, namely HA-PBA-TiO2 Janus nanocomposite, by in situ etching in prussian blue analogs doped with Co and Ni, followed by the growth of TiO2 nano-flowers and encapsulation in hyaluronic acid. When these janus nanoparticles diffused to the inflammatory sites of RA, they exhibited outstanding photocatalytic water-splitting ability under 660 nm laser irradiation, generating H2 and O2. This capability helps ameliorate the hypoxic microenvironment at RA inflammatory sites by eliminating reactive oxygen species (ROS) and enhancing antioxidation and oxygenation. Furthermore, owing to the doping of Co and Ni, HA-PBA-TiO2 exhibits photothermal conversion capability, which significant damage to FLS upon exposure to 660 nm laser irradiation, thereby controlling their aberrant proliferation. Through a series of in vitro and in vivo experiments, we validated the significant therapeutic efficacy of HA-PBA-TiO2 in treating RA, highlighting its broad prospects for application.

Highly efficient photocatalytic degradation of tetracycline antibiotic enabled by TiO2 nanodispersion

The growing pollution of antibiotics poses a significant threat to the ecological environment and human health. Photocatalysis is a promising solution for eliminating tetracycline (TC), but developing efficient photocatalysts remains a critical and challenging task. Herein, TiO2 nanodispersion is first used for the removal of TC in water. The as-prepared TiO2 nanodispersion has a uniform size of 10 nm and a large specific surface area of 198.9 m2/g, exhibiting notable adsorption capacity, exceptional photocatalytic performance, and considerable stability. Under UV light, TiO2 nanodispersion achieved 100 % degradation of TC within 60 min, using less than 1/5 of the catalyst dosage typically applied in most studies, and exhibited the highest catalytic activity, reaching 500 mgTC∙gcatalyst-1h-1. Additionally, the photocatalytic rate constant of TiO2 nanodispersion was 2.74 times higher than commercial P25. After five photocatalytic cycles, the catalyst maintained a high degradation efficiency of 94 %. Even under visible light, the degradation efficiency of TC by TiO2 nanodispersion was approximately 90 % within 20 min, which was notably higher than that of P25 (63 %). Moreover, the as-prepared TiO2 nanodispersion demonstrated outstanding photocatalytic degradation ability for other typical antibiotics (chlortetracycline, oxytetracycline, and ciprofloxacin), demonstrating its potential as an efficient photocatalyst for the treatment of antibiotic wastewater.

Preparation and performance of self-cleaning synergistic visible light catalytic coatings based on N-CQDs/Bi2WO6 for NO degradation

Due to the intensification of nitric oxide (NO) emissions caused by industrial development, visible light responsive photocatalysts have been selected and applied in building coatings as a new strategy. In this study, N-doped carbon quantum dots (N-CQDs)-Bi2WO6 (NBW) was prepared using an ethylene glycol-assisted solvothermal method. Various techniques, including XRD, FT-IR, SEM, were employed to analyze and characterize NBW. The photocatalytic performance and stability of NBW were evaluated, and the results showed that 52% of NO (Initial concentration: 600 ppb) were oxidized under visible light. NBW was dispersed in an ethyl acetate/polytetrafluoroethylene (PTFE)/polyvinylidene fluoride (PVDF) suspension and modified by 1H,1H,2H,2H-Perfluorodecyltriethoxysilane (PFDTES), to form an easy-to-spray coating referred to as CPFB. Due to the photocatalytic ability of NBW, CPFB oxidized 74% of NO under visible light and reduced the coloring of coating surfaces contaminated with methyl red. The superhydrophobicity of CPFB coating provided the foundation for its self-cleaning ability. In addition, CPFB exhibited hydrophobicity and photocatalytic performance even after tests such as photooxidation, water impact, and wear. Finally, the photocatalytic mechanism of CPFB self-cleaning coating was explored. The significance of CPFB lied in its ability to effectively combine self-cleaning, visible light-responsive photocatalysis, and durability in a single coating. This innovative approach may inspire the development of similar coatings for various applications.

Enhanced Remediation of Textile Dyes via Nonmetal-Modified Layered Graphitic Carbon Nitride: Influence of Various Oxygen Precursors

Layered two-dimensional (2D) graphitic carbon nitride (gCN)) doped with nonmetals has been extensively utilized as a photo-electrocatalyst. Herein, gCN doped with Oxygen was synthesized through a thermal polymerization process. The effect of various oxygen forerunners, namely citric acid (CA), oxalic acid (OX), and lactic acid (LA) on the photocatalytic ability of the gCN was analyzed. The proposed O-doped gCN samples basic characteristics were characterized by different analytical analyses. Indeed, the O-gCN has formed a sheet-like nature with a nanometre range, so often called a nanosheet. Superior photocatalytic performance was measured when the gCN was prepared by the CA as the O-precursor; 95% malachite green (MG) removal was attained within a short treatment time of 40min by adding a 20mg photocatalyst. The influences of different parameters of catalyst concentration, different precursors, and initial pH of MG degradation were also studied. The generation of active radicals played a major part in the degradation of the MG dye solution. These findings offer fundamental insight into utilizing the O-gCN for the remediation of textile effluents in water resources. The preparation of enormous metal-free catalysts via non-metal doping toward the environmental clean-up.

P3HT/g-C3N4 composite fiber membranes for high-performance photocatalytic hydrogen evolution

As a superstar semiconducting polymer, poly(3-hexylthiophene) (P3HT) demonstrates high efficiency in carrier transport ability and wide absorption range. However, pristine P3HT exhibits minimal photocatalytic activity as a result of its short carrier transport distance and fast electron-hole recombination. Here, we strategically fabricated P3HT/g-C3N4 composites on polymethyl methacrylate (PMMA) fiber (PTCN) via electrospinning and the physicochemical properties were fully investigated. Raman spectroscopy, ultraviolet–visible (UV–Vis) absorption spectra and X-ray photoelectron spectroscopy (XPS) results demonstrated a well-defined p-n heterojunctions can be formed between P3HT and g-C3N4 molecules through π-π interaction and extended conjugated length of P3HT could be achieved by tuning the ratios of P3HT relative to g-C3N4. The presence of the heterojunctions facilitates the effective disconnection of the electron-hole pairs, resulting in a significantly enhanced photocatalytic hydrogen evolution rate of 7327 μ mol/(h·g) for the PTCN fiber membranes. This value exceeds that of P3HT fibers by 57.7 times and powder g-C3N4 by 6.8 times, respectively. The high photocatalytic hydrogen production activity of P3HT/g-C3N4 fiber membrane expands the application of P3HT. More importantly, these results indicate that the construction of heterojunction fiber materials is a promising approach for improving the photocatalytic ability of conjugated semiconducting polymers.

Tunable and selective transformation of aromatic thioether enabled by regulating active species under visible light irradiation

Through effective regulation of active species in photocatalytic process, the oxidation or C(sp3)‐S bond cleavage upgrading of widespread aryl alkyl sulfides under mild conditions was successfully achieved by using a pyridinium photocatalyst. Benefiting from the excellent redox ability of the photocatalyst, the electron transfer between the pyridinium molecule and the substrate, molecular oxygen, or counter‐anion effectively promotes the conversion and upgrading of the substrate thioether. Among them, the efficient generation of reactive oxygen species (ROS) enables the highly selective oxidation of sulfides to sulfoxides under visible light and air atmosphere. More importantly, the chlorine radical (Cl•) generated by electron transfer, reported for the first time, contributes to the cleavage of C(sp3)‐S bonds, achieving the transformation of aryl alkyl sulfides to disulfides. By harnessing the superior photocatalytic ability of pyridinium molecules, this work not only achieves the highly selective conversion of thioether by taming the active species in the photocatalytic process, but also sheds light on the untapped potential of chlorine radicals in the field of C(sp3)‐S bond activation and cleavage.

The Effect of Heat Treatment on the Sol–Gel Preparation of TiO2/ZnO Catalysts and Their Testing in the Photodegradation of Tartrazine

This study aims to synthesize TiO2/ZnO powders and to study the effect of heat treatment on their photocatalytic ability against the Tartrazine anionic dye. The as-obtained powders with the following compositions—90TiO2/10ZnO and 10TiO2/90ZnO (mol%)—were obtained by the sol–gel technique. The prepared gels were annealed at 500 °C and 700 °C and subsequently characterized by XRD, UV–Vis, and SEM methods. The single crystalline phase of TiO2, which has been detected at up to 500 °C is anatase, while for ZnO, it is the hexagonal wurtzite structure. Further increases in the temperature (700 °C) led to the appearance of rutile in the samples. The SEM analysis demonstrated that the binary oxide materials had irregular shaped particles with a tendency to agglomerate. The UV–Vis spectra of the gels exhibited a red shift in the cut-off of the 90TiO2/10ZnO sample compared with pure Ti(IV) butoxide. Photocatalytic tests showed that the investigated samples possessed photocatalytic activity toward Tartrazine. Compared with TiO2, the prepared TiO2/ZnO photocatalysts showed superior properties in the photodegradation of a Tartrazine water solution. The target photocatalysts’ enhanced photocatalytic activities can be explained by their reduced band gap energy, improved surface physicochemical characteristics, separation of photo-induced electron–hole pairs, and lowered recombination rate. Higher photocatalytic activity was observed for powders annealed at 500 °C, with the 10TiO2/90ZnO (mol%) sample exhibiting the highest photocatalytic degradation of the used organic dye.

Fluorescent Scandium Microspheres for Highly Efficient White‐Light Photocatalysis

AbstractEfficient photocatalysts play an important role in the various fields such as pollutant treatment and the generation of clean energy. Therefore, developing a photocatalyst with high activity is of great significance. Herein, scandium‐based fluorescent microspheres (Sc‐FMs) are facilely prepared through the one‐pot hydrothermal polymerization of scandium ions and tartaric acid. The prepared Sc‐FMs show strong blue solid‐state fluorescence, with a maximum emission at 412 nm. Meanwhile, Sc‐FMs possess a strong white‐light photocatalysis ability, which can be used for the photodegradation of dye pollutants (rhodamine 6 G) under low power white light without the assistance of any radical generating agents. In addition, the Sc‐FMs display good stability and recyclability. As a result, this new and efficient Sc‐FMs photocatalysts hold a promise for potential applications in environmental treatment.

Antibacterial and Antifungal Characteristics of Hydroxyl Apatite Composite Material Coated on Nitrogen-doped TiO2 (HA/N-TiO2)

Photocatalytic technology using nano-material HA/TiO2 has been widely applied worldwide to treat pollutants, kill airborne gram-negative and gram-positive bacteria, and candida fungi, especially indoor air. In this study, HA/N-TiO2 material was synthesized with oxidation-reduction absorption properties and photocatalytic ability in the visible-light irradiation that helps reduce costs compared to using ultraviolet light (UV). The structure and morphology of the material were evaluated using XRD, SEM methods, showing HA/N-TiO2 has a spherical crystal structure, sharp, and uniform with particle sizes ranging from 10 to 30 nm. To assessment of the antibacterial and antifungal efficiency of the material, we inoculated the culture of microorganisms on 10x10 cm tiles coated with HA/N-TiO2 solution with the coating thickness of 0.3 µm. This coating thickness resulted in optimal antibacterial efficacy. With continuous fluorescent light 20 W exposure for 1-9 hours, up to 96-100% of inoculated bacteria were eliminated. In real-scale experiments on the wall surfaces, the quantity of bacteria and mold decreased by 20% after 30 days when treated with HA/N-TiO2 solution compared to the control sample. HA/N-TiO2 material has the potential to treat bacteria and fungi on a practical scale if there is further cost-benefit analysis extensive research.

Lattice Distortion Creates Enhancements in Photocatalytic and Electrocapacitive Performance of Sol–Gel‐Derived Cu‐Doped NiTiO3

A remarkable 35% enhancement in the photocatalytic and electrocatalytic abilities of an ilmenite nickel titanate (NiTiO3) material is reported. This boost in catalytic performance is achieved by simply creating a static distortion in the rhombohedral unit cell by replacing a small proportion of a small‐size nondegenerate Ni (69 pm) with a large‐size degenerate Cu (73 pm). The materials are synthesized by using a simple sol–gel method. The appropriate doping amount of Cu facilitates the better separation of intrinsic charge carrier pairs by inhibiting their recombination. The photocatalytic and electrochemical activities of durable materials in aqueous MB dye (10 ppm) and KOH (1 molar) electrolyte solutions are found to be directly associated with this improvement in inherent charge carrier transfer characteristics. The enhanced photodissociation of MB dye (42–56%) and specific capacitance (381–450 F g−1) in a KOH (1 molar) electrolyte are in full accord with the investigations carried out using crystallographic and optoelectronic analysis, charging–discharging measurements, and electrochemical impedance (EIS) spectroscopy investigations. Same material with high textural surface areas or controllable particle morphologies might show a far better photo/electrocatalytic performance in a variety of practical applications.

Porous biochar supported PET plastic waste MOF heterostructure as a novel, efficient and recyclable catalyst for acetaminophen degradation

Herein, the innovative hybrid photocatalyst PET-based Zn-MOF on orange peel biochar (BC)(PZM/BC) was designed and synthesized via the hydrothermal method. Electrochemical methods have been used to demonstrate the action of the PET-MOF in the PZM/BC photocatalyst as a medium for electron transfer. The latter involved the synthesis of a zinc-containing metal–organic framework (MOF) in which the linkers were derived from the depolymerization of polyethylene terephthalate (PET) originating from plastic wastes. According to research, the catalytic reactions are sped up when porous BC and linker PET are assimilated into PZM/BC photocatalyst hetero-junction. Furthermore, BC stored electrons under light and released these electrons under dark conditions. When BC was combined with PET-MOF, the electrons on the biochar activated the catalytic redox activity of acetaminophen. Additionally, it lowers the reassimilation rate due to the combined meshed nanostructures and functionality of PET-MOF and PZM/BC. UV–Vis DRS, Mott-Schottky, Photoluminescence(PL), and Electrochemical Impedance spectra(EIS) results showed that the PZM/BC exhibited efficient spatial separation and transportation of photogenerated charge carriers and exhibited superior photocatalytic ability. Electron spin resonance(ESR) analysis confirmed that ⋅OH and h+ were the predominant radical species responsible for the degradation of acetaminophen(ACT). The optimum conditions for ACT removal were observed at pH 6.07, with a PZM/BC dosage of 0.1 g L−1, and an initial ACT concentration of 50 mg L−1, highlighting the pivotal role of the PZM/BC system in ACT degradation. Furthermore, potential photocatalytic degradation pathways of ACT were inferred renders on the identified intermediates which are responsible for the degradation of refractory intermediates. Regeneration trials were carried out to assess the stability of the photocatalyst. Additionally, the degraded intermediates generated during the degradation processes were examined, providing a comprehensive elucidation of the degradation mechanism.Graphical

Multifunctional Hydrogel Containing Oxygen Vacancy‐Rich WOx for Synergistic Photocatalytic O2 Production and Photothermal Therapy Promoting Bacteria‐Infected Diabetic Wound Healing

AbstractAn effective method capable of simultaneously providing antibacterial activity, blood glucose regulation, and angiogenesis promotion for healing bacteria‐infected diabetic wounds is not reported to date, but urgently required. In this study, a hydrogel composite (γ‐PGA/PDA/GOx/WOx (PPGW)), endowed with these desired attributes is fabricated by incorporating polydopamine (PDA), glucose oxidase (GOx), and tungsten oxide (WOx) nanowires into the poly(γ‐glutamic acid) (γ‐PGA) framework. The exceptional photothermal conversion properties of PDA facilitated notable antibacterial effects on bacteria‐infected diabetic wounds; GOx regulated high blood glucose by consuming glucose and generating hydrogen peroxide (H2O2); while WOx nanowires displayed remarkable photocatalytic abilities, converting H2O2 into oxygen (O2) when exposed to 808‐nm near‐infrared radiation. Density functional theory calculations and experiments are conducted to confirm the mechanism of WOx‐mediated photocatalytic degradation of H2O2 to produce O2. These transformations aided in alleviating the hypoxic conditions in wounds associated with diabetes, expediting angiogenesis, and fostering cell crawling and proliferation. Consequently, the multifunctional hydrogel dressing PPGW, featuring photothermal, antibacterial, and enzyme‐catalyzed activity reduces hyperglycemia at the wound site. Moreover, photocatalytic O2 production represents a promising strategy for addressing chronic bacteria‐infected diabetic wounds.

Elaborate construction of a MOF-derived novel morphology Z-scheme ZnO/ZnCdS heterojunction for enhancing photocatalytic H2 evolution and tetracycline degradation

Elaborate construction of novel Z-scheme heterojunction with exceptional morphology derived from metal-organic framework (MOF) have been attracted greatly interest for improving the photocatalytic ability. Herein, a Z-scheme ZnO/ZnCdS heterojunction of rare morphology with ultrathin-nanosheet assembled hierarchical morphology ZnCdS supporting on rich gap ZnO nanospheres were constructed from Zn-based MOF (namely PZH-139) for the first time. This unique feature increased specific surface area, offered abundant mass transport channels and accessible catalytic active sites, accelerated electron migration, which highly elevated photocatalytic property. Furthermore, electron paramagnetic resonance (EPR) measurements and density functional theory (DFT) calculations confirmed the reservation of strong redox capability owing to Z-scheme electron transfer path and the ΔGH* closer to zero of Z-scheme ZnO/ZnCdS system were another two key factors for boosting the photocatalytic activity. As a result, 3-ZnO-700/ZnCdS-160 with optimal morphology showed the best H2 generation performance of 15.43 mmol h−1 g−1 and degradation tetracycline (TC) efficiency of 98.14 %. This work offered a novel and feasible idea for elaborate synthesis of the high-efficiency Z-scheme ZnO/ZnCdS heterojunction with special morphology derived from Zn-MOF.

Advances in noble metal-modified g-C3N4 heterostructures toward enhanced photocatalytic redox ability

Advances in noble metal-modified g-C3N4 heterostructures toward enhanced photocatalytic redox ability

Surface microstructure regulation of a novel N-CQDs /C3N4/Bi2WO6 self-cleaning synergistic photocatalytic degradation of NO coating

As well known, the apparent structure and chemical composition of self-cleaning photocatalytic coatings are crucial for their application. In this study, C3N4 with a large specific surface area was introduced into N-CQDs/Bi2WO6 to construct a highly catalytic active catalyst (CBW-0.5), which continuously degraded 57.7 % of NO. A robust self-cleaning photocatalytic coating (CCBW-B) was prepared by firmly bonding CBW-0.5 to the substrate through a layered spraying process. CBW-0.5 endowed CCBW-B with high catalytic activity, maintaining a degradation rate of 64.9 % for NO, and most of the surface organic dye contamination was degraded after 36 h. Due to the appropriate arrangement of low surface energy substances and micro/nano particles on the surface, CCBW-B with a graded cross network on the surface has contact angles (CA) of 156°/145° for water/olive oil, respectively. The influence of each component of CCBW-B on its photocatalytic and liquid repellent ability was studied, and the patterns for the differences in coating performance due to the changes in surface roughness structure caused by different layer distributions was discussed. In addition, the mechanism for the excellent performance of CCBW-B was explored using SEM, specific surface area, and the theory of the generation and distribution of air pockets. Finally, the durability and self-cleaning ability of CCBW-B were tested, and the synergistic mechanism of self-cleaning and photocatalysis was also provided.

Glucose-assisted preparation of vacancy-rich ZnO sheets for photocatalytic activity enhancement

Vacancy-rich ZnO sheets with (1 0 0) facet were synthesized by the glucose-assisted calcination method. By introducing glucose to control the atmosphere, oriented growth of ZnO with oxygen vacancy was realized. Experimental results showed that the glucose-assisted calcination provided oxygen-poor environment for the formation of oxygen vacancy and promoted the transformation of ZnO from rods to sheets. ZnO sheets exhibited a high photocatalytic activity and regeneration ability. After 60 min of irradiation, methyl orange was completely decolorized and the degradation rate was still at 96 % after four-cycle experiments. The synergistic effect of oxygen vacancy and non-polar (1 0 0) facet improved the photocatalytic property of ZnO.

Surface Optimization of Noble-Metal-Free Conductive [Mn1/4Co1/2Ni1/4]O2 Nanosheets for Boosting Their Efficacy as Hybridization Matrices.

Conductive 2D nanosheets have evoked tremendous scientific efforts because of their high efficiency as hybridization matrices for improving diverse functionalities of nanostructured materials. To address the problems posed by previously reported conductive nanosheets like poorly-interacting graphene and cost-ineffective RuO2 nanosheets, economically feasible noble-metal-free conductive [MnxCo1-2xNix]O2 oxide nanosheets are synthesized with outstanding interfacial interaction capability. The surface-optimized [Mn1/4Co1/2Ni1/4]O2 nanosheets outperformed RuO2/graphene nanosheets as hybridization matrices in exploring high-performance visible-light-active (λ>420nm) photocatalysts. The most efficient g-C3N4-[Mn1/4Co1/2Ni1/4]O2 nanohybrid exhibited unusually high photocatalytic activity (NH4 + formation rate: 1.2mmol g-1 h-1), i.e., one of the highest N2 reduction efficiencies. The outstanding hybridization effect of the defective [Mn1/4Co1/2Ni1/4]O2 nanosheets is attributed to the optimization of surface bonding character and electronic structure, allowing for improved interfacial coordination bonding with g-C3N4 at the defect sites. Results from spectroscopic measurements and theoretical calculations reveal that hybridization helps optimize the bandgap energy, and improves charge separation, N2 adsorptivity, and surface reactivity. The universality of the [Mn1/4Co1/2Ni1/4]O2 nanosheet as versatile hybridization matrices is corroborated by the improvement in the electrocatalytic activity of hybridized Co-Fe-LDH as well as the photocatalytic hydrogen production ability of hybridized CdS.

Enhanced Hg(II) reduction activity over two-dimensional n-n heterojunction MoS2/Bi2WO6 nanocomposites under visible light illumination

The engineering of band structure acts as an effective avenue to promote photocatalytic redox reactions, which can be achieved by fabricating heterojunction photocatalysts. Herein, MoS2 NPs were anchored on the surface of the mesoporous Bi2WO6 network through a facile sol-gel process to form heterostructure MoS2/Bi2WO6 nanocomposites. HR-TEM and XRD results of the obtained MoS2/Bi2WO6 nanocomposite verified the formation of the hexagonal phase of MoS2 and the Bi2WO6 in the orthorhombic phase. The MoS2/Bi2WO6 nanocomposites displayed enhancement harvest in the visible light domain and photocatalytic ability in comparison with the pristine Bi2WO6. The photocatalytic ability of MoS2/Bi2WO6 nanocomposites was assessed by the Hg(II) reduction upon visible light irradiation. The optimal 12% MoS2/Bi2WO6 photocatalyst displayed the superior reduction of Hg(II) about 99% after 50 min, and the rate constant reached 0.1220 min-1 according to pseudo-first-order kinetic, where it was larger three folds than pristine Bi2WO6 (0.0418 min-1). The outstanding photocatalytic ability of n-n heterojunction MoS2/Bi2WO6 photocatalyst was accredited to the huge surface area, wide photoabsorption, and high separation efficiency of photocarriers. The reduction ability of MoS2/Bi2WO6 photocatalyst remained at 94% in the recycle five times, indicating its good reusability and high stability. The obtained heterojunction with the S-scheme mechanism could inhibit the recombination of the photocarriers, thus leading to superb photocatalytic ability. This work emerges an efficient route to design S-scheme heterojunction Bi2WO6-based photocatalytic methods for energy conversion and environmental purification.

Silver nanoparticle-decorated reduced graphene oxide/ nanocrystalline titanium metal-organic frameworks composite membranes with enhanced nanofiltration performance and photocatalytic ability

Nanofiltration (NF) has garnered significant attention for removing persistent dyes from industrial wastewater. However, limited membrane separation efficiency and performance deterioration due to membrane fouling are the primary challenges hindering the broader application of NF technology. Herein, we developed high-performance silver nanoparticle-coated reduced graphene oxide/nanocrystalline MIL125(Ti) composite NF membranes (nAg-rGO/n-MIL), which feature self-cleaning capabilities through photocatalytic activity. This was achieved by intercalating nanocrystalline MIL-125(Ti) (n-MIL) metal-organic frameworks between graphene oxide (GO) nanosheets, followed by reducing the GO nanosheets and decorating them with silver nanoparticles (nAg) via UV exposure. The nAg-rGO/n-MIL demonstrated high water permeability (21.7 LMH/bar) and achieved excellent removal efficiencies for targeting dyes with relatively small molecular weights ranging from 300 to 500Da. Additionally, when operated in an NF system equipped with a UV side-emitting optical fiber, the nAg-rGO/n-MIL exhibited significantly reduced water flux decline and enhanced removal efficiencies, achieving up to 97.5% for methylene blue. Moreover, the nAg-rGO/n-MIL demonstrated high durability under the tested operating conditions, indicating its potential for long-term use in industrial applications. The GO composite membrane, with nanosized MOF-intercalated nanochannels and photocatalytic activity via nAg decoration and GO reduction, offers a promising solution to performance limitations and fouling issues in current nanofiltration membranes.