In situ constructed B-CdS/Cd Schottky junctions for efficient photocatalytic CO2 reduction under visible light

CdS with a visible light response and energy band location suitable for CO2 photoreduction has received extensive attention. However, low product selectivity and photocatalytic efficiency limit its application. Here, NaBH4 is used as a reducing agent to generate Cd metal on the surface of CdS nanorods in situ. This leads to the construction of a B-CdS/Cd metal cocatalyst/semiconductor structure. This configuration significantly enhanced the CdS's activity of photocatalytic CO2 reduction. The Cd metal which is on the surface of CdS nanorods promoted the separation and transfer of photogenerated charges and increased both light photosensitivity and CO2 adsorption capabilities. The improved B-CdS/Cd catalyst shows excellent CO2 reduction capabilities by generating CO at a rate of 323.39 μmol g − 1 h − 1, which is 2.01 times more than pure CdS, owing to the synergistic enhancements. Simultaneously, Cd acts as an active site inhibiting H2 production during the CO2 reduction reaction. This work demonstrates the potential of Cd metal as a metal cocatalyst in photocatalytic CO2 reduction.