In situ Irradiated XPS Investigation on S‐Scheme TiO2@ZnIn2S4 Photocatalyst for Efficient Photocatalytic CO2 Reduction

Abstract Reasonable design of efficient hierarchical photocatalysts has gained significant attention. Herein, a step‐scheme (S‐scheme) core‐shell TiO 2 @ZnIn 2 S 4 heterojunction is designed for photocatalytic CO 2 reduction. The optimized sample exhibits much higher CO 2 photoreduction conversion rates (the sum yield of CO, CH 3 OH, and CH 4 ) than the blank control, i.e., ZnIn 2 S 4 and TiO 2 . The improved photocatalytic performance can be attributed to the inhibited recombination of photogenerated charge carriers induced by S‐scheme heterojunction. The improvement is also attributed to the large specific surface areas and abundant active sites. Meanwhile, S‐scheme photogenerated charge transfer mechanism is testified by in situ irradiated X‐ray photoelectron spectroscopy, work function calculation, and electron paramagnetic resonance measurements. This work provides an effective strategy for designing highly efficient heterojunction photocatalysts for conversion of solar fuels.