Construction of MXene/Bi2WO6 Schottky Junction for Highly Efficient Piezocatalytic Hydrogen Evolution and Unraveling Mechanism.

For the first time, a series of MXene (Ti3C2Tx)/Bi2WO6 Schottky junction piezocatalysts were constructed, and the piezocatalytic hydrogen evolution activity was explored. Optimal Ti3C2Tx/Bi2WO6 exhibits the highest piezocatalytic hydrogen evolution rate of 764.4 µmol g-1 h-1, which is nearly 8 times higher than that of pure Ti3C2Tx and twice as high as that of Bi2WO6. This value also surpasses that of most recently reported typical piezocatalysts. Moreover, related experimental results and density functional theory calculations reveal that Ti3C2Tx/Bi2WO6 can provide unique channels for efficient electron transfer, enhance piezoelectric properties, optimize the adsorption Gibbs free energy of water, reduce activation energy for hydrogen atoms, endow robust separation capacity of charge carrier, and restrict the electron-hole recombination rate, thus significantly promoting the efficiency of hydrogen evolution reaction. Ultimately, we have unraveled an innovative piezocatalytic mechanism. This work broadens the scope of MXene materials in a sustainable energy piezocatalysis application.

A Review on Bi2WO6-Based Materials for Photocatalytic CO2 Reduction.

Photocatalytic reduction of CO2 (PCR) technology offers the capacity to transmute solar energy into chemical energy through an eco-friendly and efficacious process, concurrently facilitating energy storage and carbon diminution, this innovation harbors significant potential for mitigating energy shortages and ameliorating environmental degradation. Bismuth tungstate (Bi2WO6) is distinguished by its robust visible light absorption and distinctive perovskite-type crystal architecture, rendering it highly efficiency in PCR. In recent years, numerous systematic strategies have been investigated for the synthesis and modification of Bi2WO6 to enhance its photocatalytic performance, aiming to achieve superior applications. This review provides a comprehensive review of the latest research progress on Bi2WO6 based materials in the field of photocatalysis. Firstly, outlining the fundamental principles, associated reaction mechanisms and reduction pathways of PCR. Then, the synthesis strategy of Bi2WO6-based materials is introduced for the regulation of its photocatalytic properties. Furthermore, accentuating the extant applications in CO2 reduction, including metal-Bi2WO6, semiconductor-Bi2WO6 and carbon-based Bi2WO6 composites etc. while concludes with an examination of the future landscape and challenges faced. This review hopes to serve as an effective reference for the continuous improvement and implementation of Bi2WO6-based photocatalysts in PCR.

Defect Engineering of Bi2WO6 for Enhanced Photocatalytic Degradation of Antibiotic Pollutants.

Infiltration of excessive antibiotics into aquatic ecosystems plays a significant role in antibiotic resistance, a major global health challenge. It is therefore critical to develop effective technologies for their removal. Herein, defect-rich Bi2WO6 nanoparticles are solvothermally prepared via epitaxial growth on pristine Bi2WO6 seed nanocrystals, and the efficiency of the photocatalytic degradation of ciprofloxacin, a common antibiotic, is found to increase markedly from 62.51% to 98.27% under visible photoirradiation for 60 min. This is due to the formation of a large number of structural defects, where the synergistic interactions between grain boundaries and adjacent dislocations and oxygen vacancies lead to an improved separation and migration efficiency of photogenerated carriers and facilitate the adsorption and degradation of ciprofloxacin, as confirmed in experimental and theoretical studies. Results from this work demonstrate the unique potential of defect engineering for enhanced photocatalytic performance, a critical step in removing antibiotic contaminants in aquatic ecosystems.

Surface termination modulation for superior S-Scheme Bi2WO6/BiOI heterojunction photocatalyst: a hybrid density functional study.

The prevailing theoretical frameworks indicate that depending on the growth conditions, the Bi2WO6(001) surface can manifest in three distinct terminations-DL-O-Bi (DL: double layers), O-Bi, and O-W. In this study, we conduct a comprehensive examination of the interplay between these terminations on Bi2WO6(001) and the 1I-terminated BiOI(001) facet, especially focusing on their impact on the photocatalytic activity of Bi2WO6/BiOI heterostructure, applying hybrid functional calculations. The models formulated for this research are designated as Bi2WO6(O-Bi)/BiOI(1I), Bi2WO6(DL-O-Bi)/BiOI(1I), and Bi2WO6(O-W)/BiOI(1I). Our findings reveal that Bi2WO6(O-Bi)/BiOI(1I) shows a type II band alignment, which facilitates the spatial separation of photo-generated electrons and holes. Notably, the Bi2WO6(DL-O-Bi)/BiOI(1I) configuration has the lowest binding energy and results in an S-scheme (or Step-scheme) heterostructure. In contrast to the type II heterostructure, this particular configuration demonstrates enhanced photocatalytic efficiency due to improved photo-generated carrier separation, augmented oxidation capability, and better visible-light absorption. Conversely, Bi2WO6(O-W)/BiOI(1I) presents a type I projected band structure, which is less conducive for the separation of photo-generated electron-hole pairs. In summation, this investigation points out that one could significantly refine the photocatalytic efficacy of not only Bi2WO6/BiOI but also other heterostructure photocatalysts by modulating the coupling of different terminations via precise crystal synthesis or growth conditions.

Magnetic recyclable visible light-driven Bi2WO6/Fe3O4/RGO for photocatalytic degradation of Microcystin-LR: Mechanism, pathway, and influencing factors.

Photocatalysis was an attractive strategy that had potential to tackle the Microcystin-LR (MC-LR) contamination of aquatic ecosystems. Herein, magnetic photocatalyst Fe3O4/Bi2WO6/Reduced graphene oxide composites (Bi2WO6/Fe3O4/RGO) were employed to degrade MC-LR. The removal efficiency and kinetic constant of the optimized Bi2WO6/Fe3O4/RGO (Bi2WO6/Fe3O4-40%/RGO) was 1.8 and 2.3 times stronger than the pure Bi2WO6. The improved activity of Bi2WO6/Fe3O4-40%/RGO was corresponded to the expanded visible light adsorption ability and reduction of photogenerated carrier recombination efficiency through the integration of Bi2WO6 and Fe3O4-40%/RGO. The MC-LR removal efficiency exhibited a positive tendency to the initial density of algae cells, fulvic acid, and the concentration of MC-LR decreased. The existed anions (Cl-, CO3-2, NO3-, H2PO4-) reduced MC-LR removal efficiency of Bi2WO6/Fe3O4-40%/RGO. The Bi2WO6/Fe3O4-40%/RGO could degrade 79.3% of MC-LR at pH = 7 after 180 min reaction process. The trapping experiments and ESR tests confirmed that the h+, ∙OH, and ∙O2- played a significant role in MC-LR degradation. The LC-MS/MS result revealed the intermediates and possible degradation pathways.

Bi2WO6/TiO2-based visible light-driven photoelectrochemical enzyme biosensor for glucose measurement.

Nowadays, the frequent occurrence of food adulteration makes glucose detection particularly important in food safety and quality management. The quality and taste of honey are closely related to the glucose content. However, due to the drawbacks of expensive equipment, complex operating procedures, and time-consuming processes, the application scope of traditional glucose detection methods is limited. Hence, this study developed a photoelectric chemical (PEC) sensor, which is composed of a photoactive material of bismuth tungstate (Bi2WO6) with titanium dioxide (TiO2) and glucose oxidase (GOD), for simple and rapid detection of glucose. Notably, the composites' absorption prominently increased in the visible light region, and the photo-generated electron-hole pairs were efficiently separated by virtue of the unique nanostructure system, thus playing a crucial role in facilitating PEC activity. In the presence of dissolved oxygen, the photocurrent intensity was enhanced by H2O2 generated from glucose under electro-oxidation specifically catalyzed by GOD fixed on the modified electrode. When the working potential was 0.3 V, the changes of photocurrent response indicated that the PEC enzyme biosensor provides a low detection limit (3.8 µM), and a wide linear range (0.008-8 mM). This method has better selectivity in honey samples and broad application prospects in clinical diagnosis for future.

Construction of Bi2WO6/g-C3N4 Z-Scheme Heterojunction and Its Enhanced Photocatalytic Degradation of Tetracycline with Persulfate under Solar Light.

Z-scheme heterojunction Bi2WO6/g-C3N4 was obtained by a novel hydrothermal process; its photocatalysis-persulfate (PDS) activation for tetracycline (TC) removal was explored under solar light (SL). The structure and photoelectrochemistry behavior of fabricated samples were well characterized by FT-IR, XRD, XPS, SEM-EDS, UV-vis DRS, Mott-Schottky, PL, photocurrent response, EIS and BET. The critical experimental factors in TC decomposition were investigated, including the Bi2WO6 doping ratio, catalyst dosage, TC concentration, PDS dose, pH, co-existing ion and humic acid (HA). The optimum test conditions were as follows: 0.4 g/L Bi2WO6/g-C3N4 (BC-3), 20 mg/L TC, 20 mg/L PDS and pH = 6.49, and the maximum removal efficiency of TC was 98.0% in 60 min. The decomposition rate in BC-3/SL/PDS system (0.0446 min-1) was 3.05 times higher than that of the g-C3N4/SL/PDS system (0.0146 min-1), which might be caused by the high-efficiency electron transfer inside the Z-scheme Bi2WO6/g-C3N4 heterojunction. Furthermore, the photogenerated hole (h+), superoxide (O2•-), sulfate radical (SO4•-) and singlet oxygen (1O2) were confirmed as the key oxidation factors in the BC-3/SL/PDS system for TC degradation by a free radical quenching experiment. Particularly, BC-3 possessed a wide application potential in actual antibiotic wastewater treatment for its superior catalytic performance that emerged in the experiment of co-existing components.

Preparation and Photocatalytic Performance of In2O3/Bi2WO6 Type II Heterojunction Composite Materials.

Bismuth-based photocatalytic materials have been widely used in the field of photocatalysis in recent years due to their unique layered structure. However, single bismuth-based photocatalytic materials are greatly limited in their photocatalytic performance due to their poor response to visible light and easy recombination of photogenerated charges. At present, constructing semiconductor heterojunctions is an effective modification method that improves quantum efficiency by promoting the separation of photogenerated electrons and holes. In this study, the successful preparation of an In2O3/Bi2WO6 (In2O3/BWO) II-type semiconductor heterojunction composite material was achieved. XRD characterization was performed to conduct a phase analysis of the samples, SEM and TEM characterization for a morphology analysis of the samples, and DRS and XPS testing for optical property and elemental valence state analyses of the samples. In the II-type semiconductor junction system, photogenerated electrons (e-) on the In2O3 conduction band (CB) migrate to the BWO CB, while holes (h+) on the BWO valence band (VB) transfer to the In2O3 VB, promoting the separation of photoinduced charges, raising the quantum efficiency. When the molar ratio of In2O3/BWO is 2:6, the photocatalytic degradation degree of rhodamine B (RhB) is 59.4% (44.0% for BWO) after 60 min illumination, showing the best photocatalytic activity. After four cycles, the degradation degree of the sample was 54.3%, which is 91.4% of that of the first photocatalytic degradation experiment, indicating that the sample has good reusability. The XRD results of 2:6 In2O3/BWO before and after the cyclic experiments show that the positions and intensities of its diffraction peaks did not change significantly, indicating excellent structural stability. The active species experiment results imply that h+ is the primary species. Additionally, this study proposes a mechanism for the separation, migration, and photocatalysis of photoinduced charges in II-type semiconductor junctions.

Efficient removal of tetracycline hydrochloride through novel Fe/BiOBr/Bi2WO6 photocatalyst prepared by dual-strategy under visible-light irradiation.

It is important to investigate whether combining two modification strategies has a synergistic effect on the activity of photocatalysts. In this manuscript, Fe-doped BiOBr/Bi2WO6 heterojunctions were synthesized by a one-pot solvothermal method, and excellent photocatalytic performance was obtained for the degradation of tetracycline hydrochloride (TCH) in water without the addition of surfactant. Combining experiments and characterization, the synergistic effect between Fe ion doping and the BiOBr/Bi2WO6 heterojunction was elucidated. The Fe/BiOBr/Bi2WO6 composite photocatalyst had a beneficial void structure, enhanced visible light response, and could inhibit the recombination of photogenerated support well, which improved the photocatalytic activity. The presented experiments demonstrate that Fe/BiOBr/Bi2WO6 removes 97% of TCH from aqueous solution, while pure BiOBr and Bi2WO6 only remove 56% and 65% of TCH, respectively. Finally, the separation and transfer mechanisms of photoexcited carriers were determined in conjunction with the experimental results. This study provides a new direction for the design of efficient photocatalysts through the use of a dual co-modification strategy.

Enabling Interfacial Lattice Matching by Selective Epitaxial Growth of CuS Crystals on Bi2WO6 Nanosheets for Efficient CO2 Photoreduction into Solar Fuels.

Photocatalytic CO2 reduction serves as an important technology for value-added solar fuel production; however, it is generally limited by interfacial charge transport. To address this limitation, a two-dimensional/two-dimensional (2D/2D) p-n heterojunction CuS-Bi2WO6 (CS-BWO) with highly connected and matched interfacial lattices was designed via a two-step hydrothermal tandem synthesis strategy. The integration of CuS with BWO created a robust interface electric field and provided fast charge transfer channels due to the work function difference, as well as highly connected and matched interfacial lattices. The p-n heterojunction promoted electron transfer from the Cu to Bi sites, leading to coordination of Bi sites with high electronic density and low oxidation state. The Bi sites in BWO nanosheets facilitated the adsorption and activation of CO2, and generation of high-coverage key intermediate b-CO32-, while broad light-harvesting CuS (CS) provide abundant photoinduced electrons that were injected into the conduction band of BWO for CO2 photoreduction reaction. Remarkably, the p-n heterojunction CS-BWO exhibited CO and CH4 yields of 135.7 and 62.5 µmol g-1, respectively, which were significantly higher than those of CS, BWO, and physical mixture CS-BWO nanosheets. This work provided an innovative design strategy for developing high-activity heterojunction photocatalyst for converting CO2 into value-added solar fuels.

In Situ Interfacial Engineering of CeO2 /Bi2 WO6 Heterojunction with Improved Photodegradation of Tetracycline and Organic Dyes: Mechanism Insight and Toxicity Assessment.

The construction of heterojunction photocatalysts is an auspicious approach for enhancing the photocatalytic performance of wastewater treatment. Here, a novel CeO2 /Bi2 WO6 heterojunction is synthesized using an in situ liquid-phase method. The optimal 15% CeO2 /Bi2 WO6 (CBW-15) is found to have the highest photocatalytic activity, achieving a degradation efficiency of 99.21% for tetracycline (TC), 98.43% for Rhodamine B (RhB), and 94.03% for methylene blue (MB). The TC removal rate remained at 95.38% even after five cycles. Through active species capture experiments, •O2 - , h+ , and •OH are the main active substances for TC, RhB, and MB, respectively. The possible degradation pathways for TC are analyzed using liquid chromatography-mass spectrometry (LC-MS). The photoinduced charge transfer and possible degradation mechanisms are proposed through experimentation and density functional theory (DFT) calculations. Toxicity assessment experiments show a significant reduction in toxicity during the TC degradation process. This study uncovers the mechanism of photocatalytic degradation in CeO2 /Bi2 WO6 and provides new insights into toxicity assessment.

Enabling N2 to Ammonia Conversion in Bi2 WO6 -Based Materials: A New Avenue in Photocatalytic Applications.

The field of photocatalysis has been evolving since 1972 since Honda and Fujishima's initial push for using light as an energy source to accomplish redox reactions. Since then, many photocatalysts have been studied, semiconductors or otherwise. A new photocatalytic application to convert N2 gas to ammonia (N2 fixation or nitrogen reduction reaction; NRR) has emerged. Many researchers have steered their research in this direction due to developments in the ease of ammonia detection through UV-Vis spectroscopy. This concept will specifically discuss Bi2 WO6 -based materials, techniques to enhance their photocatalytic activity (CO2 reduction, H2 production, pollutant removal, etc.), and their current application in photocatalytic NRR. Initially, a brief introduction of Bi2 WO6 along with its VB and CB potentials will be compared to various redox potentials. A final topic of interest would be a brief description of photocatalytic nitrogen fixation with additional consideration to Bi2 WO6 -based materials in N2 fixation. A major problem with photocatalytic NRR is the false ammonia quantification in Bi-based materials, which will be discussed in detail and also ways to minimize them.

Fabrication of 2D/1D Bi2WO6/halloysite nanotubes photocatalyst towards water purification: a support effect onin situconstruction and electron-hole separation.

In this research work, a reusable and efficient 2D/1D heterogeneous structured photocatalyst based on amine-functionalized halloysite nanotubes (MHNTs) and Bi2WO6nanosheet (BWO) was prepared using a facile hydrothermal method for decomposing PPCPs under simulated sunlight. On the degradation of tetracycline hydrochloride (TCH), the effects of composite catalysts prepared under various conditions were discussed. The results showed that over BWO/MHNTs with a mass ratio was 3:1, the synthesizing temperature was 120 °C and the precursor pH value was 1, the TCH (10 mg l-1) degradation efficiency reached 100% after 1 h irradiation of simulated sunlight. Moreover, BWO/MHNTs composites kept good recovery and stable photocatalytic activity after 5 cycles. The excellent dispersion of Bi2WO6on the surface of clay minerals and the oxygen vacancy enhanced electron-hole separation may be responsible for the its high activity and stability. Futhermore, the radical capture test demonstrated that ·O-2was primarily responsible for the photodegradation of TCH. Thus, BWO/MHNTs composites exhibit a good application prospect in the field of sunlight-driven photocatalytic degradation towards PPCPs pollutants in water.

A facile two-step hydrothermal preparation of 2D/2D heterostructure of Bi2WO6/WS2 for the efficient photodegradation of methylene blue under sunlight.

A facile two-step hydrothermal method was successfully used to prepare a photocatalyst Bi2WO6/WS2 heterojunction for methyl blue (MB) photodegradation. Fabricated photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Band gap measurements were carried out by diffuse reflectance spectroscopy (DRS). Results indicated that the prepared heterostructure photocatalyst has increased visible light absorption. Photocatalytic performance was evaluated under sunlight irradiation for methylene blue (MB) degradation as a model dye. Variations in pH (4-10), amount of catalyst (0.025-0.1 g/L), and initial MB concentrations (5-20 ppm) were carried out, whereas all prepared catalysts were used to conduct the tests with a visible spectrophotometer. Degradation activity improved with the pH increase; the optimum pH was approximately 8. Catalyst concentration is directly related to degradation efficiency and reached 93.56% with 0.075 g of the catalyst. Among tested catalysts, 0.01 Bi2WO6/WS2 has exhibited the highest activity and a degradation efficiency of 99.0% in 40 min (min) for MB. MB photodegradation follows pseudo-first-order kinetics, and obtained values of kapp were 0.0482 min-1, 0.0337 min-1, 0.0205 min-1, and 0.0087 min-1 for initial concentrations of 5 ppm, 10 ppm, 15 ppm, and 20 ppm, respectively. The catalyst was reused for six cycles with a negligible decrease in the degradation activity. Heterostructure 0.01 Bi2WO6/WS2 has exhibited a photocurrent density of 16 µA cm-2, significantly higher than 2.0 and 4.5 µA cm-2 for the pristine WS2 and Bi2WO6, respectively. The findings from these investigations may serve as a crucial stepping stone towards the remediation of polluted water facilitated by implementing such highly efficient photocatalysts.

Kinetic Aspects of Benzene Degradation over TiO2-N and Composite Fe/Bi2WO6/TiO2-N Photocatalysts under Irradiation with Visible Light.

In this study, composite materials based on nanocrystalline anatase TiO2 doped with nitrogen and bismuth tungstate are synthesized using a hydrothermal method. All samples are tested in the oxidation of volatile organic compounds under visible light to find the correlations between their physicochemical characteristics and photocatalytic activity. The kinetic aspects are studied both in batch and continuous-flow reactors, using ethanol and benzene as test compounds. The Bi2WO6/TiO2-N heterostructure enhanced with Fe species efficiently utilizes visible light in the blue region and exhibits much higher activity in the degradation of ethanol vapor than pristine TiO2-N. However, an increased activity of Fe/Bi2WO6/TiO2-N can have an adverse effect in the degradation of benzene vapor. A temporary deactivation of the photocatalyst can occur at a high concentration of benzene due to the fast accumulation of non-volatile intermediates on its surface. The formed intermediates suppress the adsorption of the initial benzene and substantially increase the time required for its complete removal from the gas phase. An increase in temperature up to 140 °C makes it possible to increase the rate of the overall oxidation process, and the use of the Fe/Bi2WO6/TiO2-N composite improves the selectivity of oxidation compared to pristine TiO2-N.

Simultaneous photocatalytic tetracycline oxidation and Cr(VI) reduction by a 0D/3D hierarchical Bi2WO6@CoO Z-scheme heterostructure: In situ interfacial engineering and charge regulation mechanism.

Constructing visible-light driven semiconductor heterojunction with high redox bifunctional characteristics is a promising approach to deal with the increasingly serious environmental pollution problems, especially the coexistence of organic/heavy metal pollutants. Herein, a simple in-situ interfacial engineering strategy for the fabrication of 0D/3D hierarchical Bi2WO6@CoO (BWO) heterojunction with an intimate contact interface was successfully developed. The superior photocatalytic property was reflected not only in individual tetracycline hydrochloride (TCH) oxidation or Cr(VI) reduction, but also in their simultaneous redox reaction, which could be predominantly attributed to the outstanding light-harvesting, high carrier separation efficiency and enough redox potentials. In the simultaneous redox system, TCH acted as a hole-scavenger for Cr(VI) reduction, replacing the additional reagent. Interestingly, superoxide radical (·O2-) played the role as oxidants in TCH oxidation but as electron transfer media in Cr(VI) reduction. On account of the interlaced energy band and tight interfacial contact, a direct Z-scheme charge transfer model was established, which was verified by the active species trapping experiments, spectroscopy, and electrochemical tests. This work provided a promising strategy for the design/fabrication of highly efficient direct Z-scheme photocatalysts in environmental remediation.

Recent Progress in Photocatalytic Degradation of Water Pollution by Bismuth Tungstate.

Photocatalysis has emerged as a highly promising, green, and efficient technology for degrading pollutants in wastewater. Among the various photocatalysts, Bismuth tungstate (Bi2WO6) has gained significant attention in the research community due to its potential in environmental remediation and photocatalytic energy conversion. However, the limited light absorption ability and rapid recombination of photogenerated carriers hinder the further improvement of Bi2WO6's photocatalytic performance. This review aims to present recent advancements in the development of Bi2WO6-based photocatalysts. It delves into the photocatalytic mechanism of Bi2WO6 and summarizes the achieved photocatalytic characteristics by controlling its morphology, employing metal and non-metal doping, constructing semiconductor heterojunctions, and implementing defective engineering. Additionally, this review explores the practical applications of these modified Bi2WO6 photocatalysts in wastewater purification. Furthermore, this review addresses existing challenges and suggests prospects for the development of efficient Bi2WO6 photocatalysts. It is hoped that this comprehensive review will serve as a valuable reference and guide for researchers seeking to advance the field of Bi2WO6 photocatalysis.

Biomimetic Guided Bi2WO6/Bi2O3 Vertical Heterojunction with Controllable Microstructure for Efficient Photocatalysis.

To bridge the technical gap of heterojunction induction control in conventional semiconductor photocatalysts, a method of regulating the growth of heterojunctions utilizing biomimetic structures was designed to prepare a series of Bi2WO6/Bi2O3 vertical heterojunction nanocomposites for the disposal of environmentally hazardous tetracycline wastewater difficult to degrade by conventional microbial techniques. Porous Bi2O3 precursors with high-energy crystalline (110) dominant growth were produced using the sunflower straw bio-template technique (SSBT). Bi2WO6 with a (131) plane grew preferentially into 2.8 to 4 nm pieces on the (110) plane of Bi2O3, causing a significant density reduction between Bi2WO6 pieces and a dimensional decrease in the agglomerated Bi2WO6 spheres from 3 µm to 700 nm since Bi2WO6 grew on the structure of the biomimetic Bi2O3. The optimal 1:8 Bi2WO6/Bi2O3 coupling catalyst was obtained via adapting the ratio of the two semiconductors, and the coupling ratio of 1:8 minimized the adverse effects of the overgrowth of Bi2WO6 on degradation performance by securing the quantity of vertical heterojunctions. The material degradation reaction energy barrier and bandgap were significantly reduced by the presence of a large number of vertical heterojunction structures, resulting in a material with lower impedance and higher electron-hole separation efficiency; thus, the degradation efficiency of 1:8 Bi2WO6/Bi2O3 for tetracycline hydrochloride reached 99% within 60 min. In conclusion, this study not only successfully synthesized a novel photocatalyst with potential applications in water pollution remediation but also introduced a pioneering approach for semiconductor-driven synthesis.

S-Scheme 2D/2D Heterojunction of ZnTiO3 Nanosheets/Bi2WO6 Nanosheets with Enhanced Photoelectrocatalytic Activity for Phenol Wastewater under Visible Light.

The pollution of phenol wastewater is becoming worse. In this paper, a 2D/2D nanosheet-like ZnTiO3/Bi2WO6 S-Scheme heterojunction was synthesized for the first time through a two-step calcination method and a hydrothermal method. In order to improve the separation efficiency of photogenerated carriers, the S-Scheme heterojunction charge-transfer path was designed and constructed, the photoelectrocatalytic effect of the applied electric field was utilized, and the photoelectric coupling catalytic degradation performance was greatly enhanced. When the applied voltage was +0.5 V, the ZnTiO3/Bi2WO6 molar ratio of 1.5:1 had highest degradation rate under visible light: the degradation rate was 93%, and the kinetic rate was 3.6 times higher than that of pure Bi2WO6. Moreover, the stability of the composite photoelectrocatalyst was excellent: the photoelectrocatalytic degradation rate of the photoelectrocatalyst remained above 90% after five cycles. In addition, through electrochemical analysis, XRD, XPS, TEM, radical trapping experiments, and valence band spectroscopy, we found that the S-scheme heterojunction was constructed between the two semiconductors, which effectively retained the redox ability of the two semiconductors. This provides new insights for the construction of a two-component direct S-scheme heterojunction as well as a feasible new solution for the treatment of phenol wastewater pollution.

Construction of dual Z-scheme Bi2WO6/g-C3N4/black phosphorus quantum dots composites for effective bisphenol A degradation.

In this work, a novel dual Z-scheme Bi2WO6/g-C3N4/black phosphorus quantum dots (Bi2WO6/g-C3N4/BPQDs) composites were fabricated and utilized towards photocatalytic degradation of bisphenol A (BPA) under visible-light irradiation. Optimizing the content of g-C3N4 and BPQDs in Bi2WO6/g-C3N4/BPQDs composites to a suitable mass ratio can enhance the visible-light harvesting capacity and increase the charge separation efficiency and the transfer rate of excited-state electrons and holes, resulting in much higher photocatalytic activity for BPA degradation (95.6%, at 20 mg/L in 120 min) than that of Bi2WO6 (63.7%), g-C3N4 (25.0%), BPQDs (8.5%), and Bi2WO6/g-C3N4 (79.6%), respectively. Radical trapping experiments indicated that photogenerated holes (h+) and superoxide radicals (•O2-) played crucial roles in photocatalytic BPA degradation. Further, the possible degradation pathway and photocatalytic mechanism was proposed by analyzing the BPA intermediates. This work also demonstrated that the Bi2WO6/g-C3N4/BPQDs as effective photocatalysts was stable and have promising potential to remove environmental contaminants from real water samples.