Engineering Electronic Structure of Stannous Sulfide by Amino-Functionalized Carbon: Toward Efficient Electrocatalytic Reduction of CO2 to Formate

Engineering electronic structure to enhance the binding energies of reaction intermediates in order to achieve a high partial current density can lead to increased yield of target products. Herein, amino-functionalized carbon is used to regulate the electronic structure of tin-based catalysts to enhance activity of CO2 electroreduction. The hollow nanotubes composed of SnS (stannous sulfide) nanosheets are modified with amino-functionalized carbon layers, achieving a highest formate Faraday efficiency of 92.6% and a remarkable formate partial current density of 41.1 mA cm(-2) (a total current density of 52.1 mA cm(-2)) at a moderate overpotential of 0.9 V versus reversible hydrogen electrode, as well as a good stability. Density functional theory calculations demonstrate that the superior activity is attributed to the synergistic effect among SnS and Aminated-C in increasing the adsorption energies of the key intermediates and accelerating the charge transfer rate.