Photothermal Coupling Effect Boosts the Conversion of CO<sub>2</sub> to Solar Fuel Over Pt/ZnO Photocatalyst in a Concentrated Solar Reactor
Meiqi Wu, Yuqi Ren, Fengfan Zhu, Jiancheng Zhou, Quanhong Ma, Kai Huang, Ke Wang, Naixu Li
Abstract
The low photocatalytic reaction rate and energy conversion efficiency are the key factors restricting the direct solar-driven CO 2 production of solar fuels. Here, the photothermal coupling system based on the concentrated irradiation of Fresnel lenses was designed for the light-driven CO 2 conversion process. Under the condition of concentrated irradiation, the solar energy to chemical energy conversion efficiency increased from 0.012 to 0.264%, while the CO yield increased 120 times (from 0.96 to 115.32 μmol g –1 h –1 ) over the Pt/ZnO photocatalyst, with significant performance resulting from the increase of carrier concentration and Fermi level and the decrease of apparent activation energy. Pt nanoparticles improved the light absorption performance and surface temperature of the photocatalyst under concentrated light irradiation. Photoelectrochemical measurements, evaluation of the photocatalytic performance at different wavelengths, and apparent activation energy calculations revealed that concentrated light irradiation can be an effective way to reduce apparent activation energy (from 48.19 to 37.23 kJ/mol). This provided a potentially feasible method for efficient and green utilization of CO 2 driven by solar energy.