Sulfur vacancies engineered over Cd0.5Zn0.5S by Yb3+/Er3+ co-doping for enhancing photocatalytic hydrogen evolution

Abstract

Using ion doping to engineer sulfur vacancies over metal sulfides is an effective method to improve photocatalytic properties, such vacancies form the center of the electron-captured state to promote the separation and transfer of photogenerated carriers. In this research, Yb/Er co-doped bulk Cd_0.5Zn_0.5S (CZS) was fabricated by a one-step simple hydrothermal process, and used for evaluating the catalytic activity for aquatic hydrogen production under visible light irradiation. The results showed that the Cd_0.5Zn_0.5S:Yb(15%), Er obtained exhibited a higher efficient photocatalytic activity of hydrogen evolution, in which the efficiency of Cd_0.5Zn_0.5S:Yb(15%), Er (422.0 μmol g⁻¹ h⁻¹) was 2.7 times higher than that of bare Cd_0.5Zn_0.5S (154.7 μmol g⁻¹ h⁻¹). This can be attributed to the augmented active surface area, the broadened spectral absorption of visible light and the facilitation of the separated efficiency of the photogenerated carriers. This finding provides a simple way to activate the metal-chalcogenides with S-vacancies for optimizing the photocatalytic performance.