Electrospun Mo-doped BiVO4 photoanode on a transparent conductive substrate for solar water oxidation

Angle-independent solar radiation capture by 3D printed lattice structures for efficient photoelectrochemical water splitting

Photoelectrochemical water splitting is one of the sustainable routes to renewable hydrogen production. One of the challenges to deploying photoelectrochemical (PEC) based electrolyzers is the difficulty in the effective capture of solar radiation as the illumination angle changes throughout the day. Herein, we demonstrate a method for the angle-independent capture of solar irradiation by using transparent 3 dimensional (3D) lattice structures as the photoanode in PEC water splitting. The transparent 3D lattice structures were fabricated by 3D printing a silica sol-gel followed by aging and sintering. These transparent 3D lattice structures were coated with a conductive indium tin oxide (ITO) thin film and a Mo-doped BiVO₄ photoanode thin film by dip coating. The sheet resistance of the conductive lattice structures can reach as low as 340 Ohms per sq for ∼82% optical transmission. The 3D lattice structures furnished large volumetric current densities of 1.39 mA cm^-3 which is about 2.4 times higher than a flat glass substrate (0.58 mA cm^-3) at 1.23 V and 1.5 G illumination. Further, the 3D lattice structures showed no significant loss in performance due to a change in the angle of illumination, whereas the performance of the flat glass substrate was significantly affected. This work opens a new paradigm for more effective capture of solar radiation that will increase the solar to energy conversion efficiency.

Preparation and Applications of Electrospun Optically Transparent Fibrous Membrane

The optically transparent electrospun fibrous membrane has been widely used in many fields due to its simple operation, flexible design, controllable structure, high specific surface area, high porosity, and unique excellent optical properties. This paper comprehensively summarizes the preparation methods and applications of an electrospun optically transparent fibrous membrane in view of the selection of raw materials and structure modulation during preparation. We start by the factors that affect transmittance among different materials and explain the light transmission mechanism of the fibrous membrane. This paper also provides an overview of the methods to fabricate a transparent nanofibrous membrane based on the electrospinning technology including direct electrospinning, solution treatment after electrospinning, heat treatment after electrospinning, and surface modification after electrospinning. It further summarizes the differences in the processes and mechanisms between different transparent fibrous membranes prepared by different methods. Additionally, we study the utilization of transparent as-spun membranes as flexible functional materials, namely alcohol dipstick, air purification, self-cleaning materials, biomedicine, sensors, energy and optoelectronics, oil-water separation, food packaging, anti-icing coating, and anti-corrosion materials. It demonstrates the high transparency of the nanofibers' effects on the applications as well as upgrades the product performance.

Bimetallic phosphide decorated Mo–BiVO4 for significantly improved photoelectrochemical activity and stability

Bimetallic phosphide NiCoP decorated Mo–BiVO₄ photoanode was fabricated, and showed significantly improved photoelectrochemical activity and stability.

Review on nanoscale Bi-based photocatalysts

Nanoscale Bi-based photocatalysts are promising candidates for visible-light-driven photocatalytic environmental remediation and energy conversion. However, the performance of bulk bismuthal semiconductors is unsatisfactory. Increasing efforts have been focused on enhancing the performance of this photocatalyst family. Many studies have reported on component adjustment, morphology control, heterojunction construction, and surface modification. Herein, recent topics in these fields, including doping, changing stoichiometry, solid solutions, ultrathin nanosheets, hierarchical and hollow architectures, conventional heterojunctions, direct Z-scheme junctions, and surface modification of conductive materials and semiconductors, are reviewed. The progress in the enhancement mechanism involving light absorption, band structure tailoring, and separation and utilization of excited carriers, is also introduced. The challenges and tendencies in the studies of nanoscale Bi-based photocatalysts are discussed and summarized.

A novel Z-scheme sonocatalyst system, Er3+:Y3Al5O12@Ni(Fe0.05Ga0.95)2O4-Au-BiVO4, and application in sonocatalytic degradation of sulfanilamide

A novel Z-scheme coated composite, Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, was designed for sonocatalytic degradation of sulfanilamide and fabricated by sol-hydrothermal and calcination methods. The prepared sample was characterized by X-ray diffractometer (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDX), UV-vis diffuse reflectance spectra (DRS), fourier transform infrared (FT-IR) spectra, Raman spectra and photoluminescence (PL) spectra. In Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, Ni(Fe_0.05Ga_0.95)₂O₄ and BiVO₄ form a Z-scheme sonocatalytic system, Er³⁺:Y₃Al₅O₁₂ as an up-conversion luminescence agent (from visible-light to ultraviolet-light) provides the ultraviolet-light for satisfying the energy demand of wide band-gap Ni(Fe_0.05Ga_0.95)₂O₄ and Au nanoparticles as co-catalyst forms more active sites to enrich electrons. Also, Au nanoparticles as conductive channels promotes the electrons (e^-) from conduction band of BiVO₄ to transfer to valence band of Ni(Fe_0.05Ga_0.95)₂O₄. Due to the characteristics of valence state diversity, the Fe³⁺ and V⁵⁺ constitute a redox reaction recombination system, which can also push electrons (e^-) on conduction band of BiVO₄ to quickly transfer to valence band of Ni(Fe_0.05Ga_0.95)₂O₄. The sonocatalytic activity of Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄ nanocomposite was detected through degradation of sulfanilamide under ultrasonic irradiation. A high sonocatalytic degradation ratio (95.64%) of sulfanilamide can be obtained when the conditions of 10.00 mg/L sulfanilamide, 1.00 g/L Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄, 300 min ultrasonic irradiation and 100 mL total volume were adopted. Some factors such as ultrasonic irradiation time and cycle number on the sonocatalytic degradation efficiency are also investigated by using TOC and UV-vis spectroscopy. Subsequently, the effects of hydroxyl radicals (OH) and hole scavengers were investigated to elaborate the mechanism. The researches show that the prepared Z-scheme Er³⁺:Y₃Al₅O₁₂@Ni(Fe_0.05Ga_0.95)₂O₄-Au-BiVO₄ coated composite displayed an excellent sonocatalytic activity in degradation of sulfanilamide under ultrasonic irradiation.

Preparation and Characterization of Mo Doped in BiVO₄ with Enhanced Photocatalytic Properties

Molybdenum (Mo) doped BiVO₄ was fabricated via a simple electrospun method. Morphology, structure, chemical states and optical properties of the obtained catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), N₂ adsorption–desorption isotherms (BET) and photoluminescence spectrum (PL), respectively. The photocatalytic properties indicate that doping Mo into BiVO₄ can enhance the photocatalytic activity and dark adsorption ability. The photocatalytic test suggests that the 1% Mo-BiVO₄ shows the best photocatalytic activity, which is about three times higher than pure BiVO₄. Meanwhile, 3% Mo-BiVO₄ shows stronger dark adsorption than pure BiVO₄ and 1% Mo-BiVO₄. The enhancement in photocatalytic property should be ascribed to that BiVO₄ with small amount of Mo doping could efficiently separate the photogenerated carries and improve the electronic conductivity. The high concentration doping would lead the crystal structure transformation from monoclinic to tetragonal phase, as well as the formation of MoO₃ nanoparticles on the BiVO₄ surface, which could also act as recombination centers to decrease the photocatalytic activity.

Revisiting the behaviour of BiVO4as a carbon dioxide reduction photo-catalyst

Bismuth vanadate is a widely known photocatalyst for the hydro-reduction of CO₂.

One-step solvothermal synthesis of Fe-doped BiOI film with enhanced photocatalytic performance

Ultrathin nanosheets consisting of Fe-doped BiOI were obtained on a FTO (SnO₂:F) glass substrate via a simple solvothermal process.