Light‐Driven Syngas Production over Defective ZnIn2S4 Nanosheets

Abstract Photocatalytic syngas (CO and H 2 ) production with CO 2 as gas source not only ameliorates greenhouse effect, but also produces valuable chemical feedstocks. However, traditional photocatalytic systems require noble metal or suffers from low yield. Here, we demonstrate that S vacancies ZnIn 2 S 4 ( V S ‐ZnIn 2 S 4 ) nanosheets are an ideal photocatalyst to drive CO 2 reduction into syngas. It is found that building S vacancies can endow ZnIn 2 S 4 with stronger photoabsorption, efficient electron–hole separation, and larger CO 2 adsorption, finally promoting both hydrogen evolution reaction (HER) and CO 2 reduction reaction (CO 2 RR). The syngas yield of CO and H 2 is therefore significantly increased. In contrast to pristine ZnIn 2 S 4 , the syngas yield over V S ‐ZnIn 2 S 4 can be improved by roughly ≈4.73 times and the CO/H 2 ratio is modified from 1:4.18 to 1:1. Total amount of syngas after 12 h photocatalysis is as high as 63.20 mmol g −1 without use of any noble metals, which is even higher than those of traditional noble metal‐based catalysts in the reported literatures. This work demonstrates the critical role of S vacancies in mediating catalytic activity and selectivity, and highlights the attractive ability of defective ZnIn 2 S 4 for light‐driven syngas production.