Zn nanosheets coated with a ZnS subnanometer layer for effective and durable CO2 reduction

Electrochemical reduction of CO2 into value-added chemicals provides a facile solution to energy and environmental crisis. Non-precious metals (Zn, Cd, Sn etc.) were identified as promising catalysts for the reduction of CO2. However, their electron-rich peculiarity causes weak adsorption of reaction intermediates and poor performance for CO2 reduction. Here we report that a conceptually new electrocatalyst, Zn nanosheets coated with a porous ZnS subnanometer layer, can achieve excellent catalytic performance which is comparable with that of noble metallic catalysts. Experimental and theoretical investigations reveal that the ZnS subnanometer layer plays a similar role to S dopants, modifies the adsorption of Zn catalysts appropriately, and eventually achieves high catalytic activity. Meanwhile, different from S doping, the ZnS subnanometer layer is chemically inert during the reduction of CO2, thus providing long-term durability.