Extending photocatalysis beyond the UV-activated semiconductors, such as TiO2 and ZnO, to visible light absorbing photocatalyst has recently gained much interest in utilizing solar energy to generate renewable fuels. Visible light-activated metal oxides, like Fe2O3, Cu2O, and BiVO4, have demonstrated promising activities in photoelectrochemical water splitting and photocatalysis. However, most single photocatalysts suffer slow charge transfer, significant electron-hole recombination, and photo-corrosion. Fabricating Z-scheme heterojunctions is a practical approach to achieve total photoelectrochemical water splitting by combining a photoanode and a photocathode in one photocatalyst. This architecture enhances the spatial separation of the H2 and O2 generation while also preventing the charged carrier recombination. In this presentation, we describe a new method to enhance the photocatalytic activity of BiVO4 with bismuth ruthenate, Bi2Ru2O7, to produce a Z-scheme heterostructured photocatalyst of Bi2Ru2O7/BiVO4. This material is constructed by a temperature-controlled hydrothermal method at 180 °C. The as-synthesized material was characterized by x-ray diffraction spectroscopy, transmission electron microscopy, x-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The Bi2Ru2O7/BiVO4 Z-scheme heterojunction nanocomposite exhibited enhanced photocatalytic activity in degrading the organic dye, rhodamine B, compared to the individual metal oxides. Complete degradation of rhodamine B was achieved in 80 min compared to the bare Bi2Ru2O7 and BiVO4 at 300 min and 120 min, respectively. The photoelectrochemical characterization showed that the Bi2Ru2O7/BiVO4 heterojunction improved charge-carrier transfer and enhanced electron/hole separation compared to the single catalyst. This novel Bi2Ru2O7/BiVO4 nanocomposite is a promising photocatalyst for hydrogen generation via photoelectrochemical water splitting and degradation of persistent organic pollutants.

Enhancing the activity of bismuth vanadate via facial design of Z-scheme heterostructured photocatalysts

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.