Light‐Driven Syngas Production over Defective ZnIn₂S₄ Nanosheets

Abstract

Photocatalytic syngas (CO and H2) production with CO2 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 ZnIn2S4 (VS‐ZnIn2S4) nanosheets are an ideal photocatalyst to drive CO2 reduction into syngas. It is found that building S vacancies can endow ZnIn2S4 with stronger photoabsorption, efficient electron–hole separation, and larger CO2 adsorption, finally promoting both hydrogen evolution reaction (HER) and CO2 reduction reaction (CO2RR). The syngas yield of CO and H2 is therefore significantly increased. In contrast to pristine ZnIn2S4, the syngas yield over VS‐ZnIn2S4 can be improved by roughly ≈4.73 times and the CO/H2 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 ZnIn2S4 for light‐driven syngas production.

V-Substituted ZnIn2S4: A (Visible+NIR) Light-Active Photocatalyst

“…[7,8] (in the latter case, using photoelectrochemistry), which are the first ones that the present authors could detect; additionally, other more recent cases have appeared [24,[47][48][49][50]. In fact, not only H 2 can be produced by ZnIn 2 S 4 ; in recent years, it has also been found possible to photoreduce CO 2 or produce syngas, in some cases combining two semiconductors [51][52][53][54]. In many of these cases, stable and reproducible behavior was always observed.…”

Controlling metallic Co0 in ZIF-67-derived N-C/Co composite catalysts for efficient photocatalytic CO2 reduction

“…The main steps of photocatalytic CO 2 reduction include light absorption, electron-hole separation as well as transfer, and surface redox reaction [8,9]. Current research focuses on the enhancement of heterogeneous photocatalysts in the three steps [10][11][12]. Transition metal-based catalysts have been considered ideal photocatalysts for efficient photocatalytic CO 2 reduction owing to their high intrinsic activities and abundant sources [13][14][15].…”

Defective Ultrathin ZnIn2S4 for Photoreductive Deuteration of Carbonyls Using D2O as the Deuterium Source

“…As shown in Figure 5B , D‐ZIS showed a higher photocurrent response than ZIS, suggesting more efficient excited electron‐hole separation and interfacial electron transfer. [ 38 ] Upon the addition of benzophenone, a much higher photocurrent was observed for D‐ZIS while no apparent change could be detected on the ZIS electrode, further indicating the former was more effective in reducing benzophenone.…”