Solar-heating boosted catalytic reduction of CO2 under full-solar spectrum

Catalytic converting CO2 into fuels with the help of solar energy is regarded as ‘dream reaction’, as both energy crisis and environmental issue can be mitigated simultaneously. However, it is still suffering from low efficiency due to narrow solar-spectrum utilization and sluggish heterogeneous reaction kinetics. In this work, we demonstrate that catalytic reduction of CO2 can be achieved over Au nanoparticles (NPs) deposited rutile under full solar-spectrum irradiation, boosted by solar-heating effect. We found that UV and visible light can initiate the reaction, and the heat from IR light and local surface-plasmon resonance relaxation of Au NPs can boost the reaction kinetically. The apparent activation energy is determined experimentally and is used to explain the superior catalytic activity of Au/rutile to rutile in a kinetic way. We also find the photo-thermal synergy in the Au/rutile system. We envision that this work may facilitate understanding the kinetics of CO2 reduction and developing feasible catalytic systems with full solar spectrum utilization for practical artificial photosynthesis.