Photoelectrocatalytic reduction of CO2 for efficient methanol production: Au nanoparticles as electrocatalysts and light supports

Conversion of CO2 into value-added fuels and chemicals faces the challenges of high overpotential, low selectivity for desired products and sluggish multielectrons transfer kinetics. Plasmon-mediated electrocatalytic method shows the potential for overcoming these problems. In this work, choosing Au nanoparticles as duel-functional material of electrocatalyst and plasmonic support, methanol can be efficiently produced from CO2 reduction. The dependences of current density and Faradaic efficiency on Au nanoparticle size, light wavelength and light density are systematically investigated. The performance test results show that CH3OH with Faradaic efficiency as high as 52% can be obtained at the potential of ‒ 0.8 V (vs. RHE) when 20.2 nm Au NPs-modified GC electrode is under excitation by 520 nm light with light density of 120 mW/cm2. The performance results, along with the discrete dipole approximation calculation and electrochemical characterizations suggest that the efficient activation of CO2 by plasmon...