A novel CoP@AAH cocatalyst leads to excellent stability and enhanced photocatalytic H2 evolution of CdS by structurally separating the photogenerated carriers

Abstract

To alleviate the fast recombination of charges and enhance the stability of CdS, a novel CoP@amorphous aluminum hydroxide (AAH) cocatalyst was developed and loaded on CdS nanorods via an in-situ phosphorization process to structurally separate the photogenerated carriers. The AAH completely covers the CdS nanorods to form a core-shell structure, and the high-conductivity CoP nanoparticles embedded in the AAH shell act as a charge transfer bridge, making the H2 evolution reaction sites migrate far from CdS and thus prevent the photocorrosion derived from the accumulation of photogenerated holes. The optimized CdS/CoP@AAH hybrid catalyst presents a photocatalytic H2 evolution rate of 54.9 mmol/g/h, apparent quantum efficiency of 40.62% and excellent cycle stability. DFT calculations were also employed from the views of band structure and Gibbs free energy to illuminate the photocatalytic mechanism. This work offers a new strategy to restrain the photocorrosion and enhance the photocatalytic H2 production of CdS-based catalysts simultaneously.