Efficient CO2 reduction to formate using a Cu-doped BiVO4 electrocathode in a WO3 photoanode-assisted photoelectrocatalytic system

Photoelectrocatalytic CO2 reduction to formate is believed as a promising way to mitigate energy consumption and improve CO2 reduction efficiency. In this work, Cu-doped BiVO4 electrocathode catalyst is prepared to the efficient CO2 reduction to formate. Compared with pristine BiVO4, Cu-doped BiVO4 has the excellent catalytic performance for CO2 electroreduction. When the Cu doping amount is 8 %, a highest formate selectivity is detected at -1.0 V vs RHE, with a Faraday efficiency of 87.15 %. Experimental results indicate that Cu doping can adjust the electronic structure of BiVO4 and provide more active adsorption sites for CO2 activation. Furthermore, WO3 is used as the photoanode to construct the photoelectrocatalytic CO2 reduction system to further improve the selectivity of formate. Due to the synergistic effect of photocatalysis and electrocatalysis, the yield of formate in the photoelectrocatalytic system is 3.3 times higher than that in the electrocatalytic sys-tem. This work provides a compelling strategy for developing efficient photoelectrocatalytic CO2 reduction sys-tem by composing of photoanode and electrocathode.