SnS Nanoparticles Grown on Sn-Atom-Modified N,S-Codoped Mesoporous Carbon Nanosheets as Electrocatalysts for CO₂Reduction to Formate

Electrochemical conversion of carbon dioxide (CO2) to formate provides a method for the synthesis of valuable fuels and chemical products. Herein, SnS nanoparticles were grown in situ on Sn-atom-modified N,S-codoped mesoporous carbon nanosheets. As a result, a novel nanohybrid (NH) catalyst named SnS/Sn-NSC NH was obtained for CO2 electroreduction for formate production. In the obtained NHs, the synergistic effect of SnS nanoparticles (∼2.2 nm) with Sn atoms in the carbon matrix and the 3D hierarchical porous structure could provide more active sites and shorten the diffusion pathway, thereby improving the performance of CO2 reduction. The SnS/Sn-NSC NH showed a high Faradaic efficiency (FE) of formate of 91% at a low potential of -0.7 V (vs reversible hydrogen electrode, RHE). In particular, the SnS/Sn-NSC NH demonstrated a favorable FEformate value of over 80% over a wide potential range. On the basis of spectroscopic characterizations, electrochemical tests, and CO2 adsorption analyses, the origin of the enhanced catalytic performance was suggested. This work offers an efficient strategy to construct 3D hierarchical SnS/Sn-NSC NHs for enhancing formate productivity through CO2 electrocatalytic reduction.