Revealing electron numbers-binding energy relationships in heterojunctions via in-situ irradiated XPS

Photogenerated charge transfer from photocatalysts to surface sites is a crucial step in guaranteeing photocatalytic efficiency, however, comprehending this process remains a challenge. While in-situ irradiated XPS (ISI-XPS) can function as a powerful method to investigate the electron transfer route and briefly determine the electron quantity under simulated photocatalytic conditions, the precise amount of transferred photogenerated electrons is still unknown. Based on an oxygen-doped ZnIn2S4 nanosheet on carbon nanofibers heterostructure catalysis, we discovered a potential means of calculating the precise quantity of photogenerated electrons through ISI-XPS. Additionally, we further propose a parameter to describe how many photogenerated electrons can participate in the photocatalytic reaction in conjunction with performance under monochromatic light and the corresponding electron count. Concurrently, the oxygen dopants serve as active sites to enhance the photocatalytic reaction process. This study presents a fresh outlook on the utilization of ISI-XPS and imparts a more profound understanding of the mechanism.