The photothermal coupling effect boosts the conversion of CO2 to C2H4 over CeO2/WO3 heterojunctions under concentrated solar irradiation

Abstract

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 unconcentrated light irradiation. The produced 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.