Novel Br-doped Bi2WO6 photocatalyst for high-efficiency removal of norfloxacin: mechanism and photocatalytic activity.

In this work, the bismuth tungstate (Bi2WO6) photocatalyst was successfully prepared, and the pure Bi2WO6 was modified with Br (Br-Bi2WO6). The effects of different experimental conditions on the degradation of norfloxacin (NOR) solution under visible light were investigated. The Br-Bi2WO6 photocatalyst was characterized by FTIR, XRD, SEM, BET, XPS, DRS, EIS, and EPR. The results show that the Br-modified Bi2WO6 photocatalyst can effectively improve the photocatalytic performance. The best photocatalytic performance of Br-Bi2WO6 was observed when the doping amount of Br was 3%. The degradation percentage of norfloxacin can reach 94.67%. The presence of anions and cations (Cl-, SO42-, Ag+, and Cu2+) in the solution significantly inhibited the photocatalytic activity of 3%Br-Bi2WO6. The photocatalytic degradation of norfloxacin by 3%Br-Bi2WO6 was not greatly affected in the presence of HCO3- and NO3-. The characterization analysis showed that Br was successfully doped on the Bi2WO6 photocatalyst, and the original structure of Bi2WO6 was not destroyed by the addition of Br. Br doping increased the specific surface area of Bi2WO6 and decreased the band gap of Bi2WO6 resulting in a broader visible light absorption range. In addition, Br doping promoted the migration rate of photogenerated electron-hole pairs. The ·O2- and h+ played a major role in the photodegradation of norfloxacin, and the mechanism of photocatalytic degradation of norfloxacin by Br-Bi2WO6 was proposed.

3D/3D Bamboo Charcoal/Bi2WO6 Bifunctional Photocatalyst for Degradation of Organic Pollutants and Efficient H2 Evolution Coupling with Furfuryl Alcohols Oxidation.

Photocatalysis is one of the most promising pathways to relieve the environmental contamination caused by the rapid development of modern technology. In this work, we demonstrate a green manufacturing process for the 3D/3D rod-shaped bamboo charcoal/Bi2WO6 photocatalyst (210BC-BWO) by controlled carbonization temperature. A series of morphology characterization and properties investigations (XRD, SEM, UV-vis DRS, transient photocurrent response, N2 absorption-desorption isotherms) indicate a 210BC-BWO photocatalyst with higher charge separation efficiency, larger surface area, and better adsorption capacity. The excellent photocatalytic performance was evaluated by degrading rhodamine B (RhB) (98.5%), tetracycline hydrochloride (TC-HCl) (77.1%), and H2 evolution (2833 µmol·g-1·h-1) coupled with furfuryl alcohol oxidation (3097 µmol·g-1·h-1) under visible light irradiation. In addition, the possible mechanisms for degradation of organic pollutants, H2 evolution, and furfuryl alcohol oxidation were schematically investigated, which make it possible to exert photocatalysis by increasing the active radical. This study shows that the combination of bamboo charcoal and bismuth tungstate can be a powerful photocatalyst that rationally combines H2 evolution coupled with furfuryl alcohol oxidation and degradation of pollutants.

In situ single iron atom doping on Bi2WO6 monolayers triggers efficient photo-fenton reaction.

Developing an efficient photocatalytic system for hydrogen peroxide (H2O2) activation in Fenton-like processes holds significant promise for advancing water purification technologies. However, challenges such as high carrier recombination rates, limited active sites, and suboptimal H2O2 activation efficiency impede optimal performance. Here we show that single-iron-atom dispersed Bi2WO6 monolayers (SIAD-BWOM), designed through a facile hydrothermal approach, can offer abundant active sites for H2O2 activation. The SIAD-BWOM catalyst demonstrates superior photo-Fenton degradation capabilities, particularly for the persistent pesticide dinotefuran (DNF), showcasing its potential in addressing recalcitrant organic pollutants. We reveal that the incorporation of iron atoms in place of tungsten within the electron-rich [WO4]2- layers significantly facilitates electron transfer processes and boosts the Fe(II)/Fe(III) cycle efficiency. Complementary experimental investigations and theoretical analyses further elucidate how the atomically dispersed iron induces lattice strain in the Bi2WO6 monolayer, thereby modulating the d-band center of iron to improve H2O2 adsorption and activation. Our research provides a practical framework for developing advanced photo-Fenton catalysts, which can be used to treat emerging and refractory organic pollutants more effectively.

Design of Bismuth Tungstate Bi2WO6 Photocatalyst for Enhanced and Environmentally Friendly Organic Pollutant Degradation.

In this study, a chemical precipitation approach was adopted to produce a photocatalyst based on bismuth tungstate Bi2WO6 for enhanced and environmentally friendly organic pollutant degradation. Various tools such as X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), optical spectroscopy and X-ray photoelectron spectroscopy, were employed to assess the structural and morphological properties. Hence, the XRD profiles showed a well crystallized Bi2WO6 orthorhombic phase. The photocatalytic performance of the resulting photocatalyst was assessed by the decomposition of Rhodamine B (RhB) and methyl orange (MO) with a decomposition efficiency of 97 and 92%, along with the highest chemical oxygen demand of 82 and 79% during 120 min of illumination, respectively. The principal novelty of the present work is to focus on the changes in the crystalline structure, the morphology, and the optical and the photoelectrochemical characteristics of the Bi2WO6, by tuning the annealing temperature of the designed photocatalyst. Such physicochemical property changes in the as-prepared photocatalyst will affect in turn its photocatalytic activity toward the organic pollutant decomposition. The photocatalytic mechanism was elaborated based on electrochemical impedance spectroscopy, photocurrent analysis, photoluminescence spectroscopy, and radical trapping measurements. The overall data indicate that the superoxide O2•- and holes h+ are the principal species responsible for the pollutant photodegradation.

Immobilization of Bi2WO6 on Polymer Membranes for Photocatalytic Removal of Micropollutants from Water - A Stable and Visible Light Active Alternative.

In this work, bismuth tungstate Bi2WO6 is immobilized on polymer membranes to photocatalytically remove micropollutants from water as an alternative to titanium dioxide TiO2. A synthesis method for Bi2WO6 preparation and its immobilization on a polymer membrane is developed. Bi2WO6 is characterized using X-ray diffraction and UV-vis reflectance spectroscopy, while the membrane undergoes analysis through scanning electron microscopy, X-ray photoelectron spectroscopy, and degradation experiments. The density of states calculations for TiO2 and Bi2WO6, along with PVDF reactions with potential reactive species, are investigated by density functional theory. The generation of hydroxyl radicals OH• is investigated via the reaction of coumarin to umbelliferone via fluorescence probe detection and electron paramagnetic resonance. Increasing reactant concentration enhances Bi2WO6 crystallinity. Under UV light at pH 7 and 11, the Bi2WO6 membrane completely degrades propranolol in 3 and 1 h, respectively, remaining stable and reusable for over 10 cycles (30 h). Active under visible light with a bandgap of 2.91 eV, the Bi2WO6 membrane demonstrates superior stability compared to a TiO2 membrane during a 7-day exposure to UV light as Bi2WO6 does not generate OH• radicals. The Bi2WO6 membrane is an alternative for water pollutant degradation due to its visible light activity and long-term stability.

Research progress, trends, and updates on pollutants removal by Bi2WO6-based photocatalysts under visible light irradiation.

In recent years, extensive research has been conducted on bismuth tungstate (Bi2WO6) in the field of photocatalysis owing to its unique crystal structure and favorable bandgap. This study offers a comprehensive review of the research on Bi2WO6-based photocatalysts from 2007 to 2022 using bibliometric analysis. The analysis utilized the Web of Science Core Collection Database and encompassed a dataset of 2064 publications. The bibliometric analysis and science mapping were carried out using the bibliometix R-package and CiteSpace software. This analysis examined and discussed the network of relationships among countries, journals, organizations, authors, and keywords pertaining to the topic and subtopics under investigation. The findings demonstrate that China has played a significant role in this research area and has formed close collaborations with other countries. The identification of highly-cited emerging terms suggests that enhancing the photocatalytic performance of Bi2WO6-based nanomaterials is a primary research focus. Moreover, there has been increasing interest in exploring the synergistic effects of photocatalysis and adsorption as a means to improve catalytic efficiency. This study provides valuable insights for researchers seeking a deeper understanding of Bi2WO6-based photocatalysts.

Efficient Photocatalytic degradation of direct blue 15 dye using samarium doped bismuth tungstate nanosheets: A sustainable approach towards wastewater treatment.

The rare earth metal, samarium (Sm3+) doped bismuth tungstate (Bi2WO6) nanoparticles were prepared by a one-pot hydrothermal method. The powder X-ray diffraction (XRD) analysis confirmed the formation of Bi2WO6 with an orthorhombic crystal structure. The crystallite size of Bi2WO6 decreased from 20.73 to 9.25 nm as the Sm substitution in the W lattice increased. The vibrational modes of W-O, Bi-O, and Sm-O were identified in the range of 500-900 cm-1. The optical bandgap of Sm3+ doped Bi2WO6 nanoparticles increased from 2.86 to 2.95 eV with higher Sm doping levels. The surface morphology revealed the formation of flower-like sheets in the Sm3+ doped bismuth tungstate. The energy dispersive X-ray (EDX) spectrum of Sm3+ doped Bi2WO6 nanoparticles confirmed the presence of Sm, Bi, W, and O without any other impurities. The small peak detected at 1082.14 eV in the survey scan of Sm3+ doped Bi2WO6 nanoparticles belonged to Sm3d. In the photocatalytic degradation of direct blue 15 (DB15) under visible light irradiation, the efficiency of the nanoparticles increased with higher Sm3+ concentration. The obtained results demonstrated that the Sm-Bi2WO6 nanosheets could provide an effective and sustainable solution for treating the wastewater containing direct blue 15 dye.

Bismuth Tungstate Nanoplates-Vis Responsive Photocatalyst for Water Oxidation.

The development of visible-light-responsive (VLR) semiconductor materials for effective water oxidation is significant for a sustainable and better future. Among various candidates, bismuth tungstate (Bi2WO6; BWO) has attracted extensive attention because of many advantages, including efficient light-absorption ability, appropriate redox properties (for O2 generation), adjustable morphology, low cost, and profitable chemical and optical characteristics. Accordingly, a facile solvothermal method has been proposed in this study to synthesize two-dimensional (2D) BWO nanoplates after considering the optimal preparation conditions (solvothermal reaction time: 10-40 h). To find the key factors of photocatalytic performance, various methods and techniques were used for samples' characterization, including XRD, FE-SEM, STEM, TEM, HRTEM, BET-specific surface area measurements, UV/vis DRS, and PL spectroscopy, and photocatalytic activity was examined for water oxidation under UV and/or visible-light (vis) irradiation. Famous commercial photocatalyst-P25 was used as a reference sample. It was found that BWO crystals grew anisotropically along the {001} basal plane to form nanoplates, and all properties were controlled simultaneously by tuning the synthesis time. Interestingly, the most active sample (under both UV and vis), prepared during the 30 h solvothermal reaction at 433 K (BWO-30), was characterized by the smallest specific surface area and the largest crystals. Accordingly, it is proposed that improved crystallinity (which hindered charge carriers' recombination, as confirmed by PL), efficient photoabsorption (using the smallest bandgap), and 2D mesoporous structure are responsible for the best photocatalytic performance of the BWO-30 sample. This report shows for the first time that 2D mesoporous BWO nanoplates might be successfully prepared through a facile template-free solvothermal approach. All the above-mentioned advantages suggest that nanostructured BWO is a prospective candidate for photocatalytic applications under natural solar irradiation.

Gamma radiation shielding properties for polymer composites reinforced with bismuth tungstate in different proportions.

In this study, inorganic compound (Bi2(WO4)3) was added into the composite to improve the radiation shielding properties of polymer composite. A polymer matrix was prepared by combining unsaturated polyester resin with methyl ethyl ketone peroxide and cobalt octoate (6%), and Bi2(WO4)3 was added to this polymer matrix at different ratios as filling material. In order to investigate the gamma radiation attenuation properties of the obtained polymer composites, mass attenuation coefficients, radiation shielding efficiencies, radiation transmission factors, linear attenuation coefficients, half values layer, tenth values layer, mean free path values, effective atomic numbers and effective electron densities parameters were obtained. Experimental studies were carried out with the help of HPGe detector at 22 different energies emitted from 22Na, 54Mn, 57Co, 60Co, 133Ba, 137Cs, 152Eu and 241Am radioactive sources in the photon energy range of 59.5-1408.0 keV. Each obtained experimental result was compared with the theoretical results. It was observed that the sample encoded with BiWO20 is the best radiation shielding material among all studied composites (except 59.5 keV).

Key role of Fe(VI)-activated Bi2WO6 in the photocatalytic oxidation of sulfonamides: Mediated electron transfer mechanism.

The widespread use of sulfonamides (SAs) in animals and human infections has raised significant concerns regarding their presence in ambient waterways and potential for inducing antimicrobial resistance. Herein, we report on the capacity of ferrate (VI) (FeVIO42-, Fe(VI)) to facilitate the photocatalytic degradation of sulfamethazine (SMT) via bismuth tungstate (Bi2WO6, BWO) under blue LED light (Vis/BWO/Fe(VI)) exposure, at rates that were 45-fold faster than BWO photocatalysis. Both the stepwise and time-series addition of Fe(VI) contributed to the degradation. Multiple lines of evidence confirmed that the common reactive species (RSs) in BWO-based photocatalytic systems and Fe(VI)-involved systems (e.g., •OH/h+, O2•-, 1O2 and Fe(V)/Fe(IV)) played subtle roles in our study system. Herein, for the first time, it was discovered that the precursor complex (BWO-Fe(V)/Fe(IV)* )) was the main contributor to induce electron transfer of SAs through the "conductive bridge" effect of BWO. The studied system was able to effectively degrade SMT in synthetic hydrolyzed urine (SHU) with low interference from background substances in water. This work not only offers a novel facilitation strategy for BWO, but also holds a great application prospect for contamination remediation in urine.

Simplified synthesis of direct Z-scheme Bi2WO6/PhC2Cu heterojunction that shows enhanced photocatalytic degradation of 2,4,6-TCP: Kinetic study and mechanistic insights.

For this work, we employed n-type Bi2WO6 and p-type PhC2Cu to formulate a direct Z-scheme Bi2WO6/PhC2Cu (PCBW) photocatalyst via simplified ultrasonic stirring technique. An optimal 0.6PCBW composite exhibited the capacity to rapidly photodegrade 2,4,6-TCP (98.6% in 120 min) under low-power blue LED light, which was 8.53 times and 12.53 times faster than for pristine PhC2Cu and Bi2WO6, respectively. Moreover, electron spin resonance (ESR), time-resolved PL spectra, and quantitative ROS tests indicated that the PCBW enhanced the separation capacity of photocarriers. It also more readily associated with dissolved oxygen in water to generate reactive oxygen species (ROS). Among them, the ability of PCBW to produce ·O2- in one hour was 12.07 times faster than for pure PhC2Cu. In addition, the H2O2 formation rate and apparent quantum efficiency of PCBW are 10.73 times that of PhC2Cu, which indicates that PCBW not only has excellent photocatalytic performance, but also has outstanding ROS production ability. Furthermore, Ag photodeposition, in situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations were utilized to determine the photogenerated electron migration paths in the PCBW, which systematically confirmed that Z-scheme heterojunction were successfully formed. Finally, based on the intermediate products, three potential 2,4,6-TCP degradation pathways were proposed.

Coupling Benzylamine Oxidation with CO2 Photoconversion to Ethanol over a Black Phosphorus and Bismuth Tungstate S-Scheme Heterojunction.

Photoconversion of CO2 and H2 O into ethanol is an ideal strategy to achieve carbon neutrality. However, the production of ethanol with high activity and selectivity is challenging owing to the less efficient reduction half-reaction involving multi-step proton-coupled electron transfer (PCET), a slow C-C coupling process, and sluggish water oxidation half-reaction. Herein, a two-dimensional/two-dimensional (2D/2D) S-scheme heterojunction consisting of black phosphorus and Bi2 WO6 (BP/BWO) was constructed for photocatalytic CO2 reduction coupling with benzylamine (BA) oxidation. The as-prepared BP/BWO catalyst exhibits a superior photocatalytic performance toward CO2 reduction, with a yield of 61.3 µmol g-1 h-1 for ethanol (selectivity of 91 %).In situ spectroscopic studies and theoretical calculations reveal that S-scheme heterojunction can effectively promote photogenerated carrier separation via the Bi-O-P bridge to accelerate the PCET process. Meanwhile, electron-rich BP acts as the active site and plays a vital role in the process of C-C coupling. In addition, the substitution of BA oxidation for H2 O oxidation can further enhance the photocatalytic performance of CO2 reduction to C2 H5 OH. This work opens a new horizon for exploring novel heterogeneous photocatalysts in CO2 photoconversion to C2 H5 OH based on cooperative photoredox systems.

Anchoring black phosphorous quantum dots on Bi2WO6 porous hollow spheres: A novel 0D/3D S-scheme photocatalyst for efficient degradation of amoxicillin under visible light.

Reasonable regulation of the micro-morphology of material can significantly enhance the related performance. Herein, bismuth tungstate (Bi2WO6, simplified as BWO) porous hollow spheres with flower-like surface were prepared successfully, and this unique morphology endowed BWO with improved photocatalytic performance by reflecting and absorbing the light multiple times inside the cavity. To inhibit the rapid recombination of photogenerated e--h+ pairs within BWO itself, black phosphorous quantum dots (BPQDs) were anchored onto the nanosheets of BWO sphere closely by a facile self-assembly process, which will not shade the pores of BWO owing to the small size of BPQDs, but the BP nanosheets have the chance to do that. The band gap of BPQDs expanded much after exfoliation due to the quantum confinement effects, which matched the energy band of BWO well to form S-scheme heterojunction, achieving more efficient separation of photogenerated charges. As a result, the BPQDs/BWO exhibited attractive photocatalytic performance in the degradation of amoxicillin (AMX) and other antibiotics. Besides, the operation conditions were optimized, specifically, 94.5 % of AMX (20 mg/L, 200 mL) can be removed in 60 min when 50 mg of 2BPQDs/BWO was used as catalyst with solution pH = 11. Moreover, a possible degradation pathway of AMX was proposed based on the detected intermediates.

Preparation of Bismuth Tungstate/Preoxidized Acrylonitrile/Acrylic Acid Copolymer Composite Nanofiber Membrane and Its Photocatalytic Properties.

BACKGROUND: In this patent article, a novel bismuth tungstate/preoxidized acrylonitrile/ acrylic acid (AN/AA) copolymer composite nanofiber membrane was prepared, which was used as the visible light catalyst. METHODS: AN/AA copolymer was synthesized, which was electrospun with bismuth nitrate and sodium tungstate to prepare the composite nanofiber. Then the composite nanofiber was preoxidized to prepare the bismuth tungstate/preoxidized AN/AA composite nanofiber membrane containing adsorption moiety and photocatalytic active moiety. RESULTS: The photocatalytic activity of bismuth tungstate/preoxidized AN/AA composite nanofiber membrane with different preoxidized temperature, heating rate, and holding time by catalytic degradation of methylene blue was investigated. The optimal preoxidized conditions were as follows: the preoxidized temperature was heated to 200 °C with the heating rate of 1°C/min and the holding time at this temperature was 12 h. The chemical structure and morphology of the composite nanofiber membrane were characterized by FTIR, XRD, and SEM. CONCLUSION: The bismuth tungstate/preoxidized AN/AA composite nanofiber membrane obtained good photocatalytic properties and reusability under visible light. The degradation rate of methylene blue by this visible light catalyst could reach 90.24% for 4.5 h, and the degradation rate remained 81.53% for 4.5 h after 5 reuses.

Electrochemical quantification of atrazine-fulvic acid and removal through bismuth tungstate photocatalytic hybrid membranes.

Herbicides such as atrazine and humus substances such as fulvic acid are widely used in agricultural sector. They can be traced in surface and groundwater around the agriculture field at concentrations beyond the approved limit due to their mobility and persistence. Bismuth-based photocatalysts activated by visible light are potential materials for removing various organic pollutants from water bodies. These photocatalysts can also be suitable candidates for developing a hybrid membrane with anti-fouling properties. In this study, Bi2WO6 nanoparticles were synthesized via the hydrothermal method and integrated into the cellulose acetate (CA), polyetherimide (PEI), polysulfone (PSF) and polyvinylidene fluoride (PVDF) polymers via physical blending approach. The hybrid membranes were then characterized by FTIR, XPS and FESEM to confirm the chemical bonding, chemical composition and surface morphology of Bi2WO6. Thus, the pure water flux of CA (35.6 L m-2 h-1), PEI (46.56 L m-2 h-1), PSF (6.84 L m-2 h-1), and PVDF (68.47 L m-2 h-1) hybrid membranes has significantly enhanced than the pristine CA, PEI, PSF and PVDF membranes. The significant rejection of atrazine-fulvic acid was observed with hybrid membranes in the order of CA (84.1%) > PVDF (72.7%) > PEI (47.8%) > PSF (37.2%), and these membranes have shown an excellent flux recovery ratio than pristine membranes. Further, electrochemical quantification studies were performed to analyze the removal efficiency of atrazine-fulvic acid from water. In this present work, GO-modified SPE was employed for electrochemical sensing studies. The resultant CA hybrid membrane achieved removal efficiency of 84.08% for atrazine. It was observed that the Bi2WO6 established strong bonding with CA, and PVDF membranes, thus showing a significant removal efficiency and FRR than other hybrid and pristine membranes.

Enhanced Visible Light-Driven Photoelectrocatalytic Degradation of Paracetamol at a Ternary z-Scheme Heterojunction of Bi2WO6 with Carbon Nanoparticles and TiO2 Nanotube Arrays Electrode.

In this study, a ternary z-scheme heterojunction of Bi2WO6 with carbon nanoparticles and TiO2 nanotube arrays was used to remove paracetamol from water by photoelectrocatalysis. The materials and z-scheme electrode were characterised using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), EDS mapping, ultraviolet diffuse reflection spectroscopy (UV-DRS), photocurrent measurement, electrochemical impedance spectroscopy (EIS), uv-vis spectroscopy and total organic carbon measurement (TOC). The effect of parameters such as current density and pH were studied. At optimal conditions, the electrode was applied for photoelectrocatalytic degradation of paracetamol, which gave a degradation efficiency of 84% within 180 min. The total organic carbon removal percentage obtained when using this electrode was 72%. Scavenger studies revealed that the holes played a crucial role during the photoelectrocatalytic degradation of paracetamol. The electrode showed high stability and reusability therefore suggesting that the z-scheme Bi2WO6-CNP-TiO2 nanotube arrays electrode is an efficient photoanode for the degradation of pharmaceuticals in wastewater.

High-Efficiency Poly(Vinylidene Fluoride-Co-Hexafluoropropylene) Loaded 3D Marigold Flower-Like Bismuth Tungstate Triboelectric Films for Mechanical Energy Harvesting and Sensing Applications.

Triboelectric nanogenerators (TENGs) are one of the most trending energy harvesting devices because of their efficient and simple mechanism in harvesting mechanical energy from the environment into electricity. Herein, ferroelectric and dielectric bismuth tungstate (Bi2 WO6 (BWO)) with a marigold flower-like structure is prepared via a hydrothermal method, which is embedded in poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), forming a PVDF-HFP/BWO composite polymer film (CPF) to fabricate TENGs. Generally, the ferroelectric materials exhibit a large piezoelectric coefficient, high electrostatic dipole moment, and high dielectric constant. The prepared PVDF-HFP/BWO CPF reveals a high polar crystalline ß-phase which leads to enhanced piezoelectric and ferroelectric properties of the CPF, thus resulting in the increased electrical performance of the fabricated TENG. The electrical output performance of the proposed TENG is systematically investigated by varying the amount of BWO material embedded in the PVDF-HFP polymer. The fabricated PVDF-HFP/2.5 wt% BWO CPF-based TENG device exhibits the highest electrical output performance. Additionally, the robust test of the TENG device is conducted to investigate the electrical performance for long-term durability and mechanical stability. Finally, the proposed TENG is operated as a self-powered sensor, harvesting mechanical energy from daily life human activities, and powering various low-power portable electronics.

Enhanced visible-light-driven photocatalytic degradation of tetracycline by 16% Er3+-Bi2WO6 photocatalyst.

The widespread use of antibiotics in drug therapy and agriculture has seriously polluted the aquatic environment. Bismuth tungstate (Bi2WO6) is a new and efficient visible-light catalyst that is simple to prepare, non-toxic, stable, and corrosion resistant. Nonetheless, its efficiency has remained limited, and erbium (Er) mixing has been tested to address this. Here, a new Er3+-mixed Bi2WO6 photocatalyst was successfully prepared through the one-step hydrothermal method; pigments were characterized via XRD, SEM, BET, XPS, Uv-vis, PL and EIS. The results showed that the 16% Er3+-Bi2WO6 photocatalyst is a 250 nm flower-like nanosheet with a specific surface area of 67.1 m2/g and bandgap (Eg) of 2.35 eV, which provides the basis for superior performance. When the concentration of the catalyst was 0.4 g/L, 94.58% of the tetracycline (TC) solution (initial concentration of 10 mg/L) degraded within 60 min under visible light irradiation (λ ≥ 420 nm). ESR and LC-MS were used to identify the free radicals and intermediates for the degradation of TC pollutants; a photocatalytic degradation system and pathway were proposed. This solar-driven system will ultimately reduce resource consumption, providing a sustainable and energy-saving environmental decontamination strategy.

Engineering of bionic Fe/Mo bimetallene for boosting the photocatalytic nitrogen reduction performance.

The "FeMo cofactors" in biological nitrogenase play a decisive role in nitrogen reduction. Herein, a novel bionic Fe/Mo bimetallene was applied in photocatalytic nitrogen reduction. The surface coating Fe/Mo bimetallene of Bi2Mo0.3W0.7O6 (BMWO) nanocrystals could effectively promote the separation and transportation of photogenerated carriers by multi-electron redox reactions and deliver 2.8 times longer photo-carrier lifetime. Consequently, the nitrogen fixation activity of Fe/Mo bimetallene-coated BMWO nanocrystal photocatalyst was obviously enhanced (218.93 µmol g-1h-1), which was about 4.8 times that of unmodified BMWO nanocrystals. This work provides a novel approach to design bionic Fe/Mo bimetallene-modified inorganic semiconductor photocatalysts for nitrogen reduction.

Characterization and Evaluation of Layered Bi2WO6 Nanosheets as a New Antibacterial Agent.

Background: Pathogenic microorganisms are causing increasing cases of mortality and morbidity, along with alarming rates of ineffectiveness as a result of acquired antimicrobial resistance. Bi2WO6 showed good potential to be used as an antibacterial substance when exposed to visible light. This study demonstrates for the first time the dimension-dependent antibacterial activity of layered Bi2WO6 nanosheets. Materials and methods: The synthesized layered Bi2WO6 nanosheets were prepared by the hydrothermal method and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman and Fourier transform infrared spectroscopy (FTIR). Antibacterial and antibiotic-modulation activities were performed in triplicate by the microdilution method associated with visible light irradiation (LEDs). Results: Bi2WO6 nanosheets were effective against all types of bacteria tested, with MIC values of 256 µg/mL against Escherichia coli standard and resistant strains, and 256 µg/mL and 32 µg/mL against Staphylococcus aureus standard and resistant strains, respectively. Two-dimensional (2D) Bi2WO6 nanosheets showed antibacterial efficiency against both strains studied without the presence of light. Conclusions: Layered Bi2WO6 nanosheets revealed dimension-dependent antibacterial activity of the Bi2WO6 system.