Electronic Tuning of SnS₂ Nanosheets by Hydrogen Incorporation for Efficient CO₂ Electroreduction.

Abstract

Surface functionalization with atoms serves as an important strategy to modulate the catalytic activities of low-dimensional nanomaterials. Herein, we developed a facile hydrogen incorporation strategy for improving the catalytic activities of SnS₂ nanosheets toward CO₂ electroreduction. Compared with SnS₂ nanosheets, the hydrogen-incorporated SnS₂ (denoted as H-SnS₂) nanosheets exhibited high current density and Faradaic efficiency (FE) for formate. At -0.9 V vs RHE, H-SnS₂ nanosheets displayed a maximum FE of 93% for carbonaceous product, which rivals the activities of most Sn-based catalysts in CO₂ electroreduction. Mechanistic studies disclosed that the incorporation of surface hydrogen induced the electron injection into the structures of H-SnS₂ nanosheets, which largely facilitates the process of CO₂ activation. Density functional theory (DFT) calculations further revealed that hydrogen incorporation decreased the energy barrier for the formation of HCOO* intermediates, thus contributing to the CO₂-to-formate conversion on H-SnS₂ nanosheets.