ZIF/Co-C3N4 with enhanced electrocatalytic reduction of carbon dioxide activity by the photoactivation process

Abstract

Introducing the effect of light into an electrocatalytic system is an effective method to improve electrocatalytic carbon dioxide reduction (CO₂RR). Here, the composite catalyst (ZIF/Co-C₃N₄) was prepared for the electrocatalytic reduction of carbon dioxide. The Faraday efficiency of the catalytic reduction of CO₂ to CO under light could reach 90.34% at −0.67 V vs. the RHE (reversible hydrogen electrode), which was 30% higher than that obtained under darkness, and the overpotential was reduced by 200 mV. Chemical kinetics experiments and in-situ transient photovoltage (TPV) tests show that the reason for highly efficient CO₂RR is intermediate CO₂⁻ formed by activated CO₂ in the electrocatalytic system under light. This work offers a deep insight into the photo-activated electrocatalytic reduction of carbon dioxide, and also opens a new way to devise efficient catalysts for CO₂RR.