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

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 electro-catalysis 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 photo -catalysis and electrocatalysis caused by the photoanode. This work provides a reference for developing efficient CO2 reduction approaches and high-performance electrocatalysts.