Ultrathin CdS shell-sensitized hollow S-doped CeO2 spheres for efficient visible-light photocatalysis

Abstract

Highly efficient photocatalysts are urgently needed with the ever-increasing problems of environmental pollution and the energy crisis. Herein, we report a shape-controlled binary photocatalyst consisting of S-doped CeO₂ hollow spheres sensitized with ultrathin CdS shells. The core-shelled CeO_2−xS_x@CdS composite is synthesized using a simple template-assisted method followed by anion-exchange and chemical bath deposition processes. Owing to the reduced band gap caused by the oxygen vacancies in the S-doped CeO₂, and the CdS sensitization effect accelerating the interface carrier separation and transfer, the CeO_2−xS_x@CdS composite exhibits superior photocatalytic activity for hydrogen evolution (1147.2 μmol g⁻¹ h⁻¹) under visible-light illumination, which is 4.4, 11.1 and 94.8 times higher than that of CdS (258.2 μmol g⁻¹ h⁻¹), CeO_2−xS_x (103.0 μmol g⁻¹ h⁻¹) and CeO₂ (12.1 μmol g⁻¹ h⁻¹), respectively. In addition, the composite displays highly efficient organic pollutant degradation (99.8% degradation of RhB within 25 min).