Photocatalyst Sheets Composed of Particulate LaMg1/3Ta2/3O2N and Mo-Doped BiVO4 for Z-Scheme Water Splitting under Visible Light

摘要

-Scheme water splitting by photocatalyst sheets is a promising approach for efficient and scalable H-2 production. One of the most important challenges in developing such photocatalyst sheets is the application of photocatalysts with long absorption edges. In this study, RhCrOx-loaded LaMg1/3Ta2/3O2N (RhCrOx/LaMg1/3Ta2/3O2N) and Mo-doped BiVO4 (BiVO4:Mo), with absorption edges at 600 and 540 nm, are investigated as the hydrogen evolution photocatalyst and oxygen evolution photocatalyst in photocatalyst sheets, respectively. The (RhCrOx/LaMg1/3Ta2/3O2N)/Au/BiVO4:Mo sheet exhibits water splitting activity that is times higher than that of corresponding powder suspensions. Stable water splitting is achieved under visible light using the (RhCrOx/LaMg1/3Ta2/3O2N)/Au/BiVO4:Mo sheet coated with an amorphous TiO2 protective layer. However, the results show the low H-2 evolution activity of the RhCrOx/LaMg1/3Ta2/3O2N imposes a ceiling on the activity of the 'photocatalyst sheet. The surface modification of LaMg1/3Ta2/3O2N with ZrO2 effectively enhances its H-2 evolution activity by reducing the density of defects on the surface of LaMg1/3Ta2/3O2N. Accordingly, the activity of the photocatalyst sheet is almost doubled when ZrO2-modified LaMg1/3Ta2/3O2N is used. The solar-to-hydrogen energy conversion efficiency is still low (1 X 10(-3)%), although this work expands the possibility for the development of photocatalyst sheets capable of functioning under irradiation by long-wavelength photons.