Visible-light-responsive Photocatalyst Based on Nitrogen-doped Bulk Oxide YTaO4-xNy for Z-scheme Overall Water Splitting

Nitrogen doping into oxide has been proved to be an effective strategy to extend visible-light utilization of oxides with layered or channeled structure, but it is shortage for the bulk oxides free of layered or channeled structure. Here, we report a novel nitrogen-doped bulk oxide (denoted as YTaO4-xNy) with good visible light response. As benefited from the strong hybridization of N 2p and O 2p electronic state according to the density functional theory (DFT) calculations, the band gap (3.6 eV) of YTaO4 precursor was sharply narrowed to 2.4 eV on YTaO4-xNy due to the obvious uplift of the valence band maximum (VBM). After decorated with the platinum cocatalyst, the Pt/YTaO4-xNy was used as the H-2-evolving photocatalyst for assembly of Z-scheme overall water splitting system by coupling with the PtOx/WO3 as the oxygen evolution photocatalyst and using the I-/IO3- as the shuttle ions. This work enriches the material database of nitrogen-doped oxide with wide visible light absorption and shows its promising application in solar-to-chemical conversion.

Automated summary

We report a novel nitrogen-doped bulk oxide (YTaO4-xNy) with good visible light response. Through density functional theory calculations, the band gap of YTaO4 precursor was narrowed to 2.4 eV on YTaO4-xNy, and the valence band maximum was uplifted. When used as the H2-evolving photocatalyst in a Z-scheme overall water splitting system with PtOx/WO3 as the oxygen evolution photocatalyst, Pt/YTaO4-xNy showed promising performance. This study enriches the material database of nitrogen-doped oxide and demonstrates its potential application in solar-to-chemical conversion.