Enhancing photocatalytic performance of Zn2SnO4 by doping Yb: Oxygen vacancies formation and dye self-sensitization degradation

Zn2SnO4 (ZTO) is a photocatalyst with broad application prospects. To further improve the photocatalytic performance, cubic ZTO was modified by doping with the rare earth element ytterbium (Yb). A series of de-tections were used to characterize the photoelectric properties of the photocatalyst, the results demonstrate that Yb preferentially replaces Zn in the ZTO lattice, then Sn is substituted when excess Yb is present. Oxygen vacancies are formed in the lattice of Yb doped ZTO, the oxygen vacancies not only broaden the visible light response range of ZTO, but also reduce the recombination rate of photogenerated electron-hole pairs. Photo catalytic experiments show that Yb-doped ZTO has good photocatalytic performance, and self-sensitized photocatalytic mechanism has been proposed. This work provides an example for the formation and application of oxygen vacancy, and also discusses the mechanism of photosensitization, which provides a new concept for the treatment of dye wastewater.