Light-Driven Syngas Production over Defective ZnIn S Nanosheets.

Photocatalytic syngas (CO and H ) production with CO 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 S (V -ZnIn S ) nanosheets are an ideal photocatalyst to drive CO reduction into syngas. It is found that building S vacancies can endow ZnIn S with stronger photoabsorption, efficient electron-hole separation, and larger CO adsorption, finally promoting both hydrogen evolution reaction (HER) and CO reduction reaction (CO RR). The syngas yield of CO and H is therefore significantly increased. In contrast to pristine ZnIn S , the syngas yield over V -ZnIn S can be improved by roughly ≈4.73 times and the CO/H 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 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 S for light-driven syngas production.