Sb-doped SnS2 nanosheets enhance electrochemical reduction of carbon dioxide to formate

Electrocatalytic carbon dioxide (CO₂) is a forward-looking strategy to convert renewable energy into fuel. Herein, we show that the novel Sb-doped SnS₂ nanosheets were synthesized by a simple hydrothermal method for efficient electroreduction of CO₂, and the atomic ratio of Sb/Sn was controllable. The introduction of Sb significantly enhanced the current density and Faradaic efficiency for formate products compared to pristine SnS₂ nanosheets. When the Sb content was 1%, the Sb-SnS₂ nanosheets achieved a remarkable Faradaic efficiency of 90.86% for formate products at −1.1 V vs. RHE. The experimental results showed that 1% Sb-doped SnS₂ nanosheets changed the electronic structure of the Sn element, allowing the catalyst to reconfigure to generate Sn⁰ during the electrochemical reaction, while the singlet tin had a synergistic effect with Sn⁴⁺, making it easier to transport electrons on the surface and promoting the activation process of CO₂, which is a key factor to improve the electroreduction performance of CO₂.