Ag/AgBr/WO3·H2O: Visible-Light Photocatalyst for Bacteria Destruction

Participation of electrochemically inserted protons in the hydrogen evolution reaction on tungsten oxides

Understanding the mechanisms by which electrodes undergo the hydrogen evolution reaction (HER) is necessary to design better materials for aqueous energy storage and conversion. Here, we investigate the HER mechanism on tungsten oxide electrodes, which are stable in acidic electrolytes and can undergo proton-insertion coupled electron transfer concomitant with the HER. Electrochemical characterization showed that anhydrous and hydrated tungsten oxides undergo changes in HER activity coincident with changes in proton composition, with activity in the order HxWO3·H2O > HxWO3 > HxWO3·2H2O. We used operando X-ray diffraction and density functional theory to understand the structural and electronic changes in the materials at high states of proton insertion, when the oxides are most active towards the HER. H0.69WO3·H2O and H0.65WO3 have similar proton composition, structural symmetry, and electronic properties at the onset of the HER, yet exhibit different activity. We hypothesize that the electrochemically inserted protons can diffuse in hydrogen bronzes and participate in the HER. This would render the oxide volume, and not just the surface, as a proton and electron reservoir at high overpotentials. HER activity is highest in HxWO3·H2O, which optimizes both the degree of proton insertion and solid-state proton transport kinetics. Our results highlight the interplay between the HER and proton insertion-coupled electron transfer on transition metal oxides, many of which are non-blocking electrodes towards protons.

Tetrabutylammonium Tribromide-Induced Synthesis of Silver Nanowires with Ultrahigh Aspect Ratio for a Flexible Transparent Film

Silver nanowires (AgNWs) have gained significant attention from researchers as a promising material for producing flexible transparent conductive films, which can be utilized in touch and display screens. Thereinto, the ultrahigh aspect ratio AgNW network can theoretically decrease the contact resistance effectively while still retaining considerable mechanical and optical properties. However, fabrication of high-quality AgNWs with a fine diameter and high aspect ratio is still challenging. Herein, a simple and robust approach to synthesize ultrahigh aspect ratio AgNWs is presented. This study successfully fabricated AgNWs with the highest aspect ratio up to ∼4000 and an average length of ∼72 μm by utilizing tetrabutylammonium tribromide as an auxiliary additive. The manifestation of tetrabutylammonium tribromide was proven to be beneficial for the generation of silver seeds and the expansion of AgNWs. The obtained AgNWs were utilized to create a transparent conductive film that showed low sheet resistance of 22.4 Ω/sq and high transmittance and low haze of 87.71 and 4.15%, respectively. The transmittance and haze of the vacant poly(ethylene terephthalate) support were 90.13 and 2.05%, thereby offering great potential for application in flexible transparent electrodes.

Recent Trends in Plasmon-Assisted Photocatalytic CO2 Reduction

Direct photocatalytic reduction of CO₂ has become an highly active field of research. It is thus of utmost importance to maintain an overview of the various materials used to sustain this process, find common trends, and, in this way, eventually improve the current conversions and selectivities. In particular, CO₂ photoreduction using plasmonic photocatalysts under solar light has gained tremendous attention, and a wide variety of materials has been developed to reduce CO₂ towards more practical gases or liquid fuels (CH₄ , CO, CH₃ OH/CH₃ CH₂ OH) in this manner. This Review therefore aims at providing insights in current developments of photocatalysts consisting of only plasmonic nanoparticles and semiconductor materials. By classifying recent studies based on product selectivity, this Review aims to unravel common trends that can provide effective information on ways to improve the photoreduction yield or possible means to shift the selectivity towards desired products, thus generating new ideas for the way forward.

Synergy of Ag and AgBr in a Pressurized Flow Reactor for Selective Photocatalytic Oxidative Coupling of Methane

Oxidation of methane into valuable chemicals, such as C₂₊ molecules, has been long sought after but the dilemma between high yield and high selectivity of desired products remains. Herein, methane is upgraded through the photocatalytic oxidative coupling of methane (OCM) over a ternary Ag-AgBr/TiO₂ catalyst in a pressurized flow reactor. The ethane yield of 35.4 μmol/h with a high C₂₊ selectivity of 79% has been obtained under 6 bar pressure. These are much better than most of the previous benchmark performance in photocatalytic OCM processes. These results are attributed to the synergy between Ag and AgBr, where Ag serves as an electron acceptor and promotes the charge transfer and AgBr forms a heterostructure with TiO₂ not only to facilitate charge separation but also to avoid the overoxidation process. This work thus demonstrates an efficient strategy for photocatalytic methane conversion by both the rational design of the catalyst for the high selectivity and reactor engineering for the high conversion.

Synthesis, characterization of Ag-WO3/bentonite nanocomposites and their application in photocatalytic degradation of humic acid in water

In this study, Ag-WO₃/bentonite nanocomposites were synthesized through a sol-gel process, a microwave irradiation technique, and a sol-immobilization process to examine their impact on the photocatalytic activity in the degradation of humic acids. The optical and structural properties of the synthesized materials were characterized using X-ray diffraction (XRD), Fourier-transform-infrared spectra (FTIR), field emission scanning electron microscope (FE-SEM) with energy dispersive X-ray (EDX), UV-Vis diffused reflectance spectra (UV-Vis DRS), Brunauer-Emmett-Teller (BET) method, and transmission electron microscope (TEM). The presence of Ag and WO₃ peaks in the XRD and EDX spectra confirmed the synthesis of Ag-WO₃ nanoparticles in the composite. The monoclinic structure of the produced WO₃ samples are shown by powder X-ray diffraction patterns. The WO₃-based nanocomposites' photocatalytic activity was improved by the composition of Ag and bentonite, which reduced the optical bandgap energy of WO₃. The binary (Ag-WO₃) nanocomposite showed improved photocatalytic activity towards the degradation of humic acid (HA) from 58% (pristine WO3) to 82% (Ag-WO₃) when compared with the pristine WO3 sample under the visible light irradiation. Notably, the ternary (Ag-WO₃/bent) nanocomposite demonstrated an outstanding photocatalytic efficiency of HA degradation (91.0%) under normal conditions (pH = 7.0 and 25 °C). Humic acid degradation in Ag-WO₃/bent was expressed by the pseudo-first-order kinetic. To summarize, integrating Ag, WO₃, bentonite, and visible light radiation to activate HA efficiently can be offered as a successful and promising technique for wastewater treatment.

Computation and Investigation of Two-Dimensional WO3·H2O Nanoflowers for Electrochemical Studies of Energy Conversion and Storage Applications

The aim of this study is to prepare a two-dimensional (2D) WO₃·H₂O nanostructure assembly into a flower shape with good chemical stability for electrochemical studies of catalyst and energy storage applications. The 2D-WO₃·H₂O nanoflowers structure is created by a fast and simple process at room condition. This cost-effective and scalable technique to obtain 2D-WO₃·H₂O nanoflowers illustrates two attractive applications of electrochemical capacitor with an excellent energy density value of 25.33 W h kg^-1 for high power density value of 1600 W kg^-1 and good hydrogen evolution reaction results (low overpotential of 290 mV at a current density of 10 mA cm^-2 with a low Tafel slope of 131 mV dec^-1). A hydrogen evolution reaction (HER) study of WO₃ in acidic media of 0.5 M H₂SO₄ and electrochemical capacitor (supercapacitors) in 1 M Na₂SO₄ aqueous electrolyte (three electrode system measurements) demonstrates highly desirable characteristics for practical applications. Our design for highly uniform 2D-WO₃·H₂O as catalyst material for HER and active material for electrochemical capacitor studies offers an excellent foundation for design and improvement of electrochemical catalyst based on 2D-transition metal oxide materials.

All-solid-state Z-scheme Ag3PO4/CSs/AgBr heterostructures for efficient visible-light photocatalysis and the photocatalytic mechanism

A novel solid-state Z-scheme photocatalyst Ag₃PO₄/CSs/AgBr (carbon spheres, CSs) was rationally designed and successfully synthesized via a facile hydrothermal coprecipitation reaction. AgBr and Ag₃PO₄ were effectively loaded on the surface of the CSs and Ag₃PO₄/CSs/AgBr showed wide visible light absorption and superior photocatalytic performance. On the basis of ultraviolet photoelectron spectroscopy (UPS) analysis and scavenger reactions, a possible photocatalytic reaction mechanism for Ag₃PO₄/CSs/AgBr is proposed. The CSs act as a charge carrier transfer bridge for constructing the all-solid-state Z-scheme photocatalyst. The photogenerated electrons from Ag₃PO₄ and holes from AgBr congregate and recombine in the CSs phase, leaving photogenerated electrons with strong reduction abilities in the conduction band (CB) of AgBr and holes with strong oxidation abilities in the valence band (VB) of Ag₃PO₄. Some Ag⁺ ions accept electrons and turn to Ag nanoparticles (NPs), leading to the surface plasmon resonance of Ag NPs on AgBr. Therefore, the photocatalytic performance and stability were significantly improved.

Skin-inspired nanofibrillated cellulose-reinforced hydrogels with high mechanical strength, long-term antibacterial, and self-recovery ability for wearable strain/pressure sensors

The advent of electric skins (E-skin) with tactile sensation, flexibility, and human affinity characteristics have attracted considerable attention in extensive research fields, including intelligent robots and health monitoring, etc. To improve the intrinsic brittleness of hydrogels, a multifunctional E-skin was fabricated involving a TEMPO-NFC and a covalently cross-linked polyacrylamide (PAM) network. In this work, silver nanoparticles (AgNPs) as long-term antibacterial agent and conductive fillers were coated onto NFC nanofibers. Subsequently, this nanocomposite hydrogel was synthesized by free radical copolymerization of AM monomers with PNAg fibers as interpenetrating fibers network. Importantly with NFC present, the nanocomposite hydrogel exhibited superior mechanical performance and excellent self-recovery ability. The obtained sensor with excellent mechanical stability and sensing performance could detect mechanotransduction signal of human movements. This work provides a practicable method to prepare high antibacterial efficiency, excellent mechanical performance, and dual-modal nanocellulose-based hydrogel sensor for the broad-range application in human-motion detection and intelligence skins.

Eco-friendly hybrid Paper-AgBr-TiO2 for efficient photocatalytic aerobic mineralization of ethanol

In this study, a facile and effective route to prepare hybrid photocatalysts (paper-TiO₂, paper-TiO₂-AgBr and paper-AgBr-TiO₂) has been reported. The preparation procedure consisted of the direct adsorption of the previously synthesized titania nanoparticles (TiO₂ sol) to generate the TiO₂ nanosphere and the immersion process in an aqueous suspension of AgBr to form the AgBr nanoclusters on paper fibers. The synthesis technology is economic, efficient, environmentally friendly and easy to implement even at industrial scale. A cellulose-based structure with well dispersed TiO₂ particles of around 1 μm and a pseudo-liquid coating of Ag⁺ and AgBr species was obtained. All the prepared photocatalysts demonstrated effective photocatalytic performance in gaseous phase ethanol degradation with simulated sunlight illumination, through the direct mineralization to CO₂ and the parallel reaction via acetaldehyde degradation. A relevant improvement in the photocatalytic activity was noticed when TiO₂ was associated with AgBr nanocrystals, with a higher effect observed when AgBr was loaded onto the paper surface prior to TiO₂. Ag-Ti interaction reduces the pair recombination rate and increases the available charge carriers generating reactive OH- radicals from both Ag-species and TiO₂, and O₂^- radicals from Ag⁺-AgBr species, which would be involved in the ethanol degradation process.

Enhanced photocatalytic activity of CdWO4/BaTiO3 heterostructure for dye degradation

The novel UV active photocatalysts of (1 − x)CdWO4–xBaTiO3 (where x = 10, 30, 50 and 70 wt%) heterostructures were synthesized using the hydrothermal technique.

Ionic silver-infused peroxidase-like metal-organic frameworks as versatile "antibiotic" for enhanced bacterial elimination

The fabrication of multiple antibacterial modalities for combating bacterial pathogens and treating infected wounds is of vital importance. Accordingly, nanozymes have emerged as a new generation of "antibiotics" with broad-spectrum antibacterial potency and high stability; however, the further application of nanozymes in clinical medicine is still limited by their single-modal antibacterial process, which cannot eradicate bacteria totally. Herein, we infused the NH₂-MIL-88B(Fe) peroxidase-like nanomaterial with a small amount of Ag(i) to construct NH₂-MIL-88B(Fe)-Ag, a potent and benign "antibiotic" with the ability to eliminate bacteria completely. This versatile system could efficiently convert H₂O₂ into the more toxic ˙OH and release Ag(i) simultaneously, making pathogenic bacteria more vulnerable to be eliminated, which decreased the requirement for the toxic H₂O₂ and high concentration of Ag(i). More importantly, the in vivo results indicated that the synergistic germicidal system could be used for wound disinfection successfully with excellent antibacterial efficacy and negligible biotoxicity. This strategy paves the way for the development of integrated antibacterial agents with enhanced antibacterial function and alternative antibiotics.

Fabrication of ZnO@Ag@Ag3PO4 Ternary Heterojunction: Superhydrophilic Properties, Antireflection and Photocatalytic Properties

A ZnO seed layer was formed on the fluorine-doped tin oxide substrate by magnetron sputtering, and then a ZnO nanorod was grown on the ZnO seed layer by a hydrothermal method. Next, we prepared a single-crystal Ag seed layer by magnetron sputtering to form a ZnO@Ag composite heterostructure. Finally, Ag₃PO₄ crystals were grown on the Ag seed layer by a stepwise deposition method to obtain a ZnO@Ag@Ag₃PO₄ ternary heterojunction. The composite heterostructure of the material has super strong hydrophilicity and can be combined with water-soluble pollutants very well. Besides, it has excellent anti-reflection performance, which can absorb light from all angles. When Ag exists in the heterojunction, it can effectively improve the separation of photo-generated electrons and holes, and improve the photoelectric conversion performance. Based on the above characteristics, this nano-heterostructure can be used in the fields of solar cells, sensors, light-emitting devices, and photocatalysis.

Preparation of the plasmonic Ag/AgBr/ZnO film substrate for reusable SERS detection: Implication to the Z-scheme photocatalytic mechanism

In this work, a novel Ag/AgBr/ZnO SERS substrate was prepared by calcinating spin-coated zinc acetate on glass slides in the presence of ethanolamine (EA), followed by the process of impregnating-precipitation-photoreduction treatment. The SERS performances of Ag/AgBr/ZnO substrates were evaluated using aqueous crystal violet (CV) and Rhodamine 6G (R6G) as target analytes. The effects of initial immersion precursor concentration and irradiation time on the SERS performance were systematically studied. The as-prepared SERS substrate exhibited good chemical detection sensitivity, reproducibility and reusability. The optimal Ag/AgBr/ZnO (10 mM-30 min) substrates were capable of detecting 10^-12 M CV and 10^-11 M R6G aqueous solutions. The quantitative detection by the SERS substrate was investigated by constructing a linear corresponding calibration plot. The Ag/AgBr/ZnO SERS substrate was regenerated by a simple visible light driven photocatalytic process. A plausible Z-scheme visible light photocatalytic mechanism seems to account for the Ag-ZnO-AgBr system. This SERS substrate can be separated from the reaction easily, and the results indicated that the film was reusable for eight times without significantly losing the SERS efficiency, each time accompanied by a simple photo-driven regeneration. This study reveals that the Ag/AgBr/ZnO film on glass is practically applicable as an ultra-highly sensitive SERS substrate that can be readily regenerated.

Influence of Crystal Water on Crystal Structure, Electronic Structure, Band Structure, and Charge Separation of WO3·2H2O Nanosheets

In this work, we mainly investigate the influence of structure water on crystal structure, electronic structure, band structure, and charge separation of WO₃·2H₂O. It is found, for the first time, that although water is a weak electron donor, a ligand-to-metal charge transfer (LMCT) from H₂O to W occurs. The structure water contributes to the conduction band (CB) of WO₃·2H₂O, and the band gap of WO₃·2H₂O is obviously narrowed, thus increasing the light absorption obviously. Moreover, the results of EIS, photocurrent spectra, and PL show that structure water in WO₃·2H₂O also improves the charge separation and transfer efficiency of the catalyst. This is the first investigation on the LMCT transfer from structure water (a weak electron donor) to tungsten, which obviously improves light absorption and charge separation. Under visible light irradiation (λ ≥ 420 nm), WO₃·2H₂O nanosheets have a photocatalytic activity 2.3 times higher than that of WO₃ for the degradation of methylene blue (MB). The kind number of photochemical materials can be increased greatly, because structure water-contained compounds widely exist in nature.

Graphdiyne-Promoted Highly Efficient Photocatalytic Activity of Graphdiyne/Silver Phosphate Pickering Emulsion Under Visible-Light Irradiation

As a new kind of two-dimensional carbon allotrope, graphdiyne (GDY) consists of sp- and sp²-hybridized carbon atoms and has recently been used for developing highly efficient photocatalytic systems because of its unique properties. In this study, we find that GDY can form a Pickering emulsion with silver phosphate (Ag₃PO₄) nanoparticles that exhibits largely enhanced photocatalytic activity in the visible-light region. In this system, Ag₃PO₄ acts as a photocatalytically active semiconductor with GDY as the hydrophobic nanostructure. Photocatalytic activity of the Ag₃PO₄/GDY-based Pickering emulsion toward the photodegradation of methylene blue (MB) and photooxidation of water is investigated under visible-light irradiation. Compared to previous Ag₃PO₄/CNT- or Ag₃PO₄/graphene-based Pickering emulsions, the Ag₃PO₄/GDY-based emulsion efficiently catalyzes MB degradation with a higher apparent rate constant k being ∼0.477 min^-1, while for water oxidation its photocatalytic activity is also improved by 1.89 and 1.75 times, respectively. Such an enhancement in the photocatalytic activity is mainly ascribed to the capability of GDY in acting as an acceptor of the photogenerated electrons from Ag₃PO₄ nanoparticles and in facilitating the hole transportation as well as in reducing Ag⁺ to Ag⁰. This study demonstrates that GDY is a new candidate with a promising future in developing photocatalytic systems with high efficiency for real applications.

A Z-Scheme Polyimide/AgBr@Ag Aerogel with Excellent Photocatalytic Performance for the Degradation of Oxytetracycline

A novel Z-scheme polyimide (PI)/AgBr@Ag aerogel photocatalyst has been successfully synthesized by combining an in situ precipitation method and a supercritical drying method. The as-prepared PI/AgBr@Ag-50 (50 wt % AgBr@Ag in PI/AgBr@Ag) aerogel photocatalyst exhibited excellent photocatalytic activity for oxytetracycline degradation with a rate constant of 0.025 min^-1 , which was 6.9 and 2.6 times higher than that of the PI aerogel or the AgBr@Ag nanoparticles, respectively. More significantly, the PI/AgBr@Ag-50 aerogel photocatalyst showed stable cycling, which could be attributed to the high mechanical strength and 3D network of the PI aerogel. The introduction of AgBr@Ag on PI with a heterojunction structure efficiently promoted the separation of electron-hole pairs by a Z-scheme mechanism. The reduced metallic Ag nanoparticles were found to function as centers for the transfer of electrons from AgBr to PI. This work has revealed a new application for the aerogel PI/AgBr@Ag photocatalyst in environmental protection.

Synthesis of a WO3 photocatalyst with high photocatalytic activity and stability using synergetic internal Fe3+ doping and superficial Pt loading for ethylene degradation under visible-light irradiation

Synthesis of a WO₃ photocatalyst with high photocatalytic activity and stability using synergetic internal Fe³⁺ doping and superficial Pt loading for ethylene degradation under visible-light irradiation.

Titanium Phosphate Nanoplates Modified With AgBr@Ag Nanoparticles: A Novel Heterostructured Photocatalyst With Significantly Enhanced Visible Light Responsive Activity

AgBr@Ag modified titanium phosphate composites were fabricated through a two-step approach. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The optical properties of the composites were characterized by using UV-vis diffuse reflectance spectroscopy. The photocatalytic activities of the composites were investigated on the degradation of Rhodamine B and ciprofloxacin under visible light irradiation. AgBr@Ag/titanium phosphate was determined to exhibit considerably higher photocatalytic activity than the corresponding individual components. The mechanism on the enhancement of the photocatalytic activity was proposed based on the results of photoluminescence spectra and photocurrent measurements. Furthermore, the possible photocatalytic mechanisms of organic compounds degradation were also proposed.

Self-Assembled AgNP-Containing Nanocomposites Constructed by Electrospinning as Efficient Dye Photocatalyst Materials for Wastewater Treatment

The design and self-assembly of graphene oxide (GO)-based composite membranes have attracted enormous attention due to their wide application in nanomaterial and environmental fields. In this work, we have successfully developed a strategy to fabricate new composite membranes based on poly(vinyl alcohol)/poly(acrylic acid)/carboxyl-functionalized graphene oxide modified with silver nanoparticles (PVA/PAA/GO-COOH@AgNPs), which were prepared via thermal treatment and the electrospinning technique. Due to the strong π-π forces and strong electrostatic interactions of GO-COOH sheets, the prepared composite membranes and their lager surface areas were modified by scores of AgNPs, which demonstrated that a high-efficiency photocatalyst removed the organic dyes from the aqueous solutions. The prepared PVA/PAA/GO-COOH@AgNPs nanocomposite membranes showed a remarkable photocatalytic capacity in the catalytic degradation of the methylene blue dye solutions. Most importantly, the whole process was easy, mild, and eco-friendly. Additionally, the as-prepared membranes could be repeatedly used after the catalytic reaction.

Enhanced photocatalytic conversion and selectivity of nitrate reduction to nitrogen over AgCl/TiO2 nanotubes

AgCl/TiO₂ nanotubes were synthesized and the mechanism of enhanced denitrification and selectivity to N₂ was revealed.

Facile synthesis of an Ag@AgBr nanoparticle-decorated K4Nb6O17 photocatalyst with improved photocatalytic properties

An Ag@AgBr nanoparticle-decorated K₄Nb₆O₁₇ (Ag@AgBr/K₄Nb₆O₁₇) photocatalyst was prepared via the oil-in-water self-assembly method. The Ag@AgBr nanoparticles, with average diameters of 20 nm, were uniformly deposited on the K₄Nb₆O₁₇ surface. The as-prepared Ag@AgBr/K₄Nb₆O₁₇ composites exhibited high visible light absorption, high photocurrent intensity, and high charge transfer efficiency, thus enhancing the photocatalytic performance for methyl-blue (MB) dye degradation. The Ag@AgBr (20 wt%)/K₄Nb₆O₁₇ composite displayed the highest photocatalytic activity, degrading 96% of the MB solution under visible light irradiation for 60 min, which was 2.3-times and 8.5-times that of the bulk Ag@AgBr and K₄Nb₆O₁₇, respectively. The excellent photocatalytic activity of the Ag@AgBr/K₄Nb₆O₁₇ composites is due to the synergistic effect between Ag@AgBr and K₄Nb₆O₁₇, where the Ag@AgBr nanoparticles not only enhanced visible light absorption efficiency due to the Ag nanoparticles' SPR, but also greatly accelerated the separation of the photogenerated electron–hole pairs. From the UV-vis spectra, the Ag@AgBr nanoparticles greatly extend the composites' visible light absorption. The data collected from photoluminescence (PL), photocurrent and electrochemical impedance spectra (EIS) were consistent and confirmed the rapid separation of charge carriers. Moreover, the composite exhibited a larger specific surface area, which was also beneficial for the photocatalytic activity. In addition, the roles of the radical species were investigated, and the holes and ·O₂⁻ radicals were hypothesized to dominate the photocatalytic process. Based on the characterization analysis and experimental results, a possible photocatalytic mechanism for the enhancement of photocatalytic activity is proposed.

The characteristic diffraction peaks of K₄Nb₆O₁₇ and AgBr were detected instead of Ag@AgBr.

Recent advancements in supporting materials for immobilised photocatalytic applications in waste water treatment

The aim of this paper is to provide a review on the usage of different anchoring media (supports) for immobilising commonly employed photocatalysts for degradation of organic pollutants. The immobilisation of nano-sized photocatalysts can eliminate costly and impractical post-treatment recovery of spent photocatalysts in largescale operations. Some commonly employed immobilisation aids such as glass, carbonaceous substances, zeolites, clay and ceramics, polymers, cellulosic materials and metallic agents that have been previously discussed by various research groups have been reviewed. The study revealed that factors such as high durability, ease of availability, low density, chemical inertness and mechanical stability are primary factors responsible for the selection of suitable supports for catalysts. Common techniques for immobilisation namely, dip coating, cold plasma discharge, polymer assisted hydrothermal decomposition, RF magnetron sputtering, photoetching, solvent casting, electrophoretic deposition and spray pyrolysis have been discussed in detail. Finally, some common techniques adopted for the characterisation of the catalyst particles and their uses are also discussed.

Iron cation-induced biphase symbiosis of h-WO3/o-WO3·0.33H2O and their crystal phase transition

h-WO₃ and o-WO₃·0.33H₂O were proved to coexist in the same hexagonal prism nanoparticle via combination of instrumental characterization and the software simulation.

The W@WO3 ohmic contact induces a high-efficiency photooxidation performance

The W@WO₃ Ohmic-type junction exhibits superior mineralization ability for the photocatalytic degradation of acetaldehyde under UV light irradiation.

Facile synthesis of AgI/BiOI-Bi2O3 multi-heterojunctions with high visible light activity for Cr(VI) reduction

AgI sensitized BiOI-Bi2O3 composite (AgI/BiOI-Bi2O3) with multi-heterojunctions was prepared using simple etching-deposition process. Different characterization techniques were performed to investigate the structural, optical and electrical properties of the as-prepared photocatalysts. It was found that the ternary AgI/BiOI-Bi2O3 composite exhibited: (1) improved photocurrent response, (2) smaller band gap, (3) greatly reduced charge transfer resistance and (4) negative shift of flat band potential, which finally led to easier generation and more efficient separation of photo-generated electron-hole pairs at the hetero-interfaces. Thus, for the reduction of Cr(VI), AgI/BiOI-Bi2O3 exhibited excellent photocatalytic activity under visible light irradiation at near neutral pH. AgI/BiOI-Bi2O3 was optimized when the initial molar ratio of KI to Bi2O3 and AgNO3 to Bi2O3 was 1:1 and 10%, respectively. The estimated kCr(VI) on optimized AgI/BiOI-Bi2O3 was about 16 times that on pure Bi2O3. Good stability was also observed in cyclic runs, indicating that the current multi-heterostructured photocatalyst is highly desirable for the remediation of Cr(VI)-containing wastewater.