S vacant CuIn5S8 confined in a few-layer MoSe2 with interlayer-expanded hollow heterostructures boost photocatalytic CO2 reduction

The conversion of CO2 into CO, CH4 and other hydrocarbons through solar energy can alleviate the energy shortage problem. We design a novel photocatalyst with S defects CuIn5S8@MoSe2 hollow structure. The interlayer-expanded MoSe2 can increase the adsorption of intermediates. The unique hollow structure can improve the light utilization efficiency and the electron-holes separation. CuIn5S8 with S vacancies in bimetallic sites has high selectivity and photocatalytic reduction of CO2 activity. Therefore, S vacant CuIn5S8 confined in a few-layers MoSe2 with interlayer-expanded hollow heterostructures exhibit super performance for photocatalytic CO2 reduction. After 8-h light reaction, the outputs of CO and CH4 for the 15.3 wt% CuIn5S8@MoSe2 sample containing S vacancies (V-s) are 30.4 and 14.7 mu mol center dot g(-1), respectively. The mechanism is also investigated in detail through in situ Fourier transform infrared spectroscopy technology.