Regulating the Cu2Se-SnO Nanosheet Heterostructure Interface for Efficient CO2 Conversion to Tunable Syngas Ratios

Electrocatalytic conversion of CO2 to syngas is an attractive pathway for transforming CO2 into high-value chemicals, but the process still suffers from low selectivity. In our work, we construct a two-dimensional (2D) structure of Cu2Se-SnO heterojunction catalyst through a high-temperature thermal reduction method. The catalyst with two phases located in the same plane exhibits efficient charge transfer, and the tunable heterojunction interface acts as active sites for CO2 adsorption and activation. Additionally, its suitable *CO adsorption energy facilitates the desorption of intermediates, leading to the formation of CO. Finally, this catalyst demonstrates excellent selectivity for syngas, maintaining a Faradaic efficiency (FE) of over 60% across a wide range of potentials (-0.67 ~ -1.07 V vs. RHE) with adjustable syngas ratios and up to 92% FE at -0.97 V vs. RHE. This research provides a new approach for balancing reduction CO2 and competing hydrogen evolution reaction.