Band-division utilization of core-shell photocatalyst under condenser solar-light and enhancement of synergistic catalytic CO2 reduction

Abstract

The synergistic effect of intrinsic photoelectrons and thermal effects, provided by intermediate- and long-wave solar energy, is considered as the linchpin in enhancing photo-thermal catalytic CO2 reduction performance. Recently, photocatalysts possessing photothermal conversion capabilities and photocatalytic systems with adjustable incident light energy flow density have garnered significant attention. The strong condensing property of the Fresnel lens was adopted in increasing the density of incident photoelectrons simultaneously, and raising the surface temperature of the photocatalyst significantly without an external heat source. A novel core–shell photocatalyst with the photothermal conversion effect was fabricated, consisting of amorphous TiO2 and CuxO active species on Fe3O4@SiO2 core. Under optimal incident energy flux density of 3200 mW cm−2, the photocatalyst was able to reduce CO2 to CO and CH4 with the production rate of 361.39 and 70.84 μmol g−1h−1, and the solar conversion efficiency reached 1.43 %. Furthermore, a simple reaction kinetic optimization based on Langmuir-Hinshelwood model well simulated the photothermal coupling effect under different incident energy flux densities. This work demonstrates an innovative technology for the full-spectrum utilization of photocatalysts and synergistic photothermal coupling catalysis. It proposes a future development scenario for the new field of efficient solar catalytic conversion to produce solar fuels.