Synergistically Regulating D-Band Centers of Cd0.5Zn0.5S/LaCoO3 Heterojunction by Dual Electric Fields for Enhanced Photocatalytic Hydrogen Evolution

The rapid recombination of charges severely limits the activity of photocatalysis. In this article, a polarized electric field and an internal electric field are formed between catalysts by constructing an interface engineering strategy. Through the synergistic effect of double electric fields, the above problems have been effectively resolved . The granular Cd0.5Zn0.5S was attached to the LaCoO3 network structure by electrostatics, and the composite catalyst Cd0.5Zn0.5S/LaCoO3 (CL) was formed. In situ characterization by XPS, EPR, and KFAM confirmed the formation of an S-scheme heterojunction between the composite catalysts. At the same time, electrochemical and fluorescence characterization confirmed that the photogenerated carrier separation efficiency of the CL-25 composite catalyst was significantly improved. This is because the built-in electric field at the interface of the composite catalyst exerts the polarizing electric field between the individual catalysts to an extreme degree, greatly reducing the recombination rate of photogenerated carriers and effectively improving the hydrogen evolution efficiency of the composite photocatalyst. DFT theoretical calculations prove that the existence of a double electric field can greatly reduce the Gibbs free energy of hydrogen adsorption.