Photothermal coupling effect boosts the conversion of CO2 to C2H4 over CeO2/WO3 heterojunction under concentrated solar irradiation

Photothermal catalytic conversion of CO2 with H2O has exhibited improved performance in solar-to-chemical (STC) energy conversion efficiency. However, the limited rate of photocatalytic half reactions has generally hindered the full exploitation of solar energy. To address this issue, we developed a CeO2/WO3 catalyst to facilitate the photoconversion process. Under concentrated light irradiation, the energy conversion efficiency of STC was increased to 0.356 ‰, which is 27.9 times higher that under non-concentrated light irradiation. The product amount of C2H4 increased from 4.36 µmol·g-1·h-1 to 124.21 µmol·g-1·h-1, representing a 27.5-fold increase. This success could be attributed to the photo-thermal synergistic effects which provided the photoexcited carriers with additional kinetic energy. Besides, the abundance of active sites at the heterojunction interfaces shortened the charge transfer distance and facilitated C-C coupling. This research contributes to the efficient and environmentally friendly use of solar energy to drive CO2 conversion with photothermal catalytic systems, and highlights the critical importance of heterojunction interfaces during the photocatalytic reactions.