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 − 1h − 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. B-CdS/Cd catalysts are presented, where the Cd metal reduced in situ forms Schottky junctions with CdS to promote the separation efficiency of photogenerated carriers, and the Cd metal acts as both an adsorption and activation site for CO2 to improve the CO2 trapping capacity of CdS, which enhances the CO yield and at the same time inhibits the competing reaction that produces H2. [Display omitted]