Photothermal Coupling Effect Boosts the Conversion of CO2 to Solar Fuel Over Pt/ZnO Photocatalyst in a Concentrated Solar Reactor

The low photocatalytic reaction rate and energy conversionefficiencyare the key factors restricting the direct solar-driven CO2 production of solar fuels. Here, the photothermal coupling systembased on the concentrated irradiation of Fresnel lenses was designedfor the light-driven CO2 conversion process. Under thecondition of concentrated irradiation, the solar energy to chemicalenergy conversion efficiency increased from 0.012 to 0.264%, whilethe CO yield increased 120 times (from 0.96 to 115.32 mu mol g(-1) h(-1)) over the Pt/ZnO photocatalyst,with significant performance resulting from the increase of carrierconcentration and Fermi level and the decrease of apparent activationenergy. Pt nanoparticles improved the light absorption performanceand surface temperature of the photocatalyst under concentrated lightirradiation. Photoelectrochemical measurements, evaluation of thephotocatalytic performance at different wavelengths, and apparentactivation energy calculations revealed that concentrated light irradiationcan be an effective way to reduce apparent activation energy (from48.19 to 37.23 kJ/mol). This provided a potentially feasible methodfor efficient and green utilization of CO2 driven by solarenergy.