Efficient CO2 reduction to formate in a photoanode-driven photoelectrocatalysis system using a Bi2Se3/Bi2O3 nanocomposite cathode

Abstract

The conversion of CO2 into valuable chemical fuels is considered as a prospective way to solve the energy crisis and environmental problems. Photoelectrocatalysis can integrate the merits of photocatalysis and electrocatalysis to lower energy consumption and improve the catalytic efficiency. In this work, a photoanode-driven photoelectrocatalysis system was prepared with TiO2 nanotubes photoanode and Bi2Se3-Bi2O3 nanocomposite electrocathode for CO2 reduction. The electrocatalytic test results demonstrated that Bi2Se3-Bi2O3-3 cathode exhibited excellent CO2 electroreduction performance with the formate Faraday efficiency of 81.33 % at −0.9 V vs RHE and an overpotential as low as 500 mV. In the photoanode-driven photoelectrocatalysis system, the formate yield was 1.6 times higher than that in the electrocatalytic system at −1.0 V vs RHE. The increased catalytic performance in the photoelectrocatalysis system may be due to the synergistic effect between photocatalysis and electrocatalysis caused by the photoanode. This work provides a reference for developing efficient CO2 reduction approaches and high-performance electrocatalysts.