The roles of defect states in photoelectric and photocatalytic processes for ZnxCd1−xS

This work aims to investigate the role that defect states play in photoelectric and photocatalytic processes. Ternary ZnxCd1−xS with wurtzite structure is firstly synthesized, and then the defect is characterized by photoluminescence (PL) spectroscopy. It is found that the photoelectrons trapped in surface defect states exhibit different behavior in the processes of photoelectric transfer and photocatalytic hydrogen evolution. During the photocatalytic process, the surface defect states in ZnxCd1−xS act as the electron pool to improve the photocatalytic activity of water-splitting reaction. In comparison, the surface defect states serve as the recombination center that decreases the efficiency of photoelectric transfer. This finding is of great significance for the design of effective photoelectric and photocatalytic material in the field of solar energy conversion.