Hydrolysis‐Induced InOx on ZnIn2S4 Promotes Selective CO2 Photoreduction over H2 Evolution

Abstract Metal sulfides generally show high visible light photocatalytic activity, but lower selectivity in the CO 2 photoreduction due to the competitive hydrogen evolution. Here, a partial hydrolysis method is reported to promote the selective photocatalytic CO 2 reduction over ZnIn 2 S 4 . The ZnIn 2 S 4 was post‐hydrolyzed in an aqueous ammonia solution to form oxide species (ZIS‐[InO x ]). Detailed experiment and DFT calculation demonstrated that the post‐hydrolysis treatment facilely prohibits the recombination of photogenerated charge carriers and benefits CO 2 activation. Under visible light irradiation, the ZIS‐[InO x ] photocatalyst shows enhanced CO 2 ‐to‐CO conversion activity with a CO‐evolving rate of 1771 μmol g −1 h −1 , which is about 8 times higher than that over pristine ZIS and 3.5 times higher than that over bulk ZIS/In 2 O 3 . More importantly, the post hydrolysis treatment significantly prohibits the hydrogen evolution and increases the CO/H 2 ratio from 0.08 over ZIS to 1.8 over ZIS‐[InO x ]. This work provides a new strategy to prepare catalysts for photocatalytic CO 2 reduction.