Rapid Fabrication of Defective CuInP ₂ S ₆ Nanosheets for Efficient CO ₂ ‐to‐Formate Conversion over Wide Current Densities

Abstract Electrochemical CO 2 reduction reaction (CO 2 RR) to produce value‐added chemicals offers a promising approach to mitigate global warming and address the energy crisis. However, the development of highly selective and durable catalysts that perform reliably across varying operational conditions remains challenging. In this work, we report the synthesis of lithium‐intercalated CuInP 2 S 6 (Li‐CIPS) with a layered structure via a one‐step chemical vapor transport method. Compared to pristine CuInP 2 S 6 , lithium intercalation in Li‐CIPS facilitates the rapid production of ultrathin CuInP 2 S 6 nanosheets through simple soaking in water. Experimental and theoretical investigations reveal that these ultrathin Li‐CIPS nanosheets contain abundant sulfur vacancies (Vs), which can substantially enhance the CO 2 RR activity while suppressing the competing hydrogen evolution reaction. As a result, the Li‐CIPS catalyst achieves over 90% Faradaic efficiency (FE) for formate production across wide current densities ranging from 100 to 800 mA cm −2 , and it maintains stable operation over 100 h at 200 mA cm −2 . This study highlights a promising and selective AMP 2 X 6 ‐based electrocatalyst for efficient CO 2 ‐to‐formate conversion in practical applications.