Semimetal 1H‐SnS2 Enables High‐Efficiency Electroreduction of CO2 to CO

Abstract Controlling the selectivity of products in CO 2 fixation is essential to obtain desired products using phase engineering. In this study, stable semimetal 1H‐SnS 2 nanosheets are successfully synthesized by hydrogen‐assisted low‐temperature calcination for the first time. Compared with semiconductor 1T‐SnS 2 , the 1H‐SnS 2 exhibits ultrahigh CO selectivity with a Faradaic efficiency of 98.2% at −0.8 V (vs reversible hydrogen electrode) and a partial current density of 10.9 mA cm −2 in the electrocatalytic CO 2 reduction reaction. Theoretical calculations indicate that the *COOH intermediate is more stable on 1H‐SnS 2 surface than 1T‐SnS 2 surface and thus promotes the CO production. This work shows that phase engineering control can be an effective approach to regulate the selectivity of products in CO 2 RR of transition metal dichalcogenides.