Engineering oxygen vacancies in Bi2WO6 by introducing heteroatoms for enhancing photo-oxidation/reduction activities.

To improve the light-harvesting capability and electron-hole separation efficiency, a novel heteroatom-introduced Bi 2 WO 6 photocatalyst (OV–Bi 2 WO 6) with oxygen vacancies (OVs) was prepared via the partial substitution of O2− by S2− anions. The OV-Bi 2 WO 6 showed high photocatalytic properties in photo-oxidation/reduction reactions under visible-light. The OVs content could be controlled by adjusting the sulfur source amount, and the optimal OV (0.9) -Bi 2 WO 6 with suitable OVs had a high photocatalytic activity with 97.6% of MO removal and 88.2% of Cr(VI) removal efficiency. Density functional theory (DFT) calculations verified that the OVs in Bi 2 WO 6 could induce a new defect level to decrease the bandgap energy and accelerate the carrier separation/migration. Furthermore, the possible photocatalytic mechanisms for MO degradation and Cr(VI) reduction over the OV-Bi 2 WO 6 were proposed, respectively. The present work helped us to better understand the enhancement mechanism of OVs in Bi-based semiconductors and paved the way to develop high-performance photocatalysts for environmental remediation. [ABSTRACT FROM AUTHOR]