Electrocatalytic CO2 reduction using self-supported zinc sulfide arrays for selective CO production

As the issue of responding to climate change has emerged as a global concern, CO2 utilization technologies have been extensively studied. Recently, electrochemical reduction of CO2 to CO coupled with renewable energy sources is considered as the most promising approach in the industrial fields. However, expensive noble metals such as Ag and Au have been mainly used to exhibit high electrocatalytic performances, selectivity, and durability with low overpotential for CO2 electrochemical reduction reactions. In this study, we are interested in Zn-based materials with attractive possibilities as alternative materials due to good CO selectivity and controllable composition or microstructures. We successfully synthesized the zinc-blende structured ZnS electrocatalysts via a one-pot hydrothermal method using different sulfur sources. Especially the TA-ZnS electrocatalyst shows excellent CO2ER performance, which is around 83 % of CO Faraday efficiency under the potential of 1.9 V vs Ag|AgCl with suppression of hydrogen production. Furthermore, it exhibits that the characteristic stability maintains over around 80 % of CO Faraday efficiency over the wide range of potential, originating from the structural and electrochemical durability. Therefore, this work provides new insight into developing an efficient electrocatalyst with selectivity and durability as a promising candidate for CO2ER application.

Automated summary

As the issue of responding to climate change becomes a global concern, CO2 utilization technologies have been extensively studied. Among them, electrochemical reduction of CO2 to CO coupled with renewable energy sources is considered the most promising approach. Expensive noble metals such as Ag and Au have been commonly used as electrocatalysts, but in this study, zinc-blende structured ZnS materials are explored as alternative materials due to their good CO selectivity and controllable composition or microstructures. The synthesized TA-ZnS electrocatalyst demonstrates excellent CO2ER performance with around 83% CO Faraday efficiency and suppression of hydrogen production, showing stability over a wide range of potential.