Enhanced solar induced photo-thermal synergistic catalytic CO2 conversion by photothermal material decorated TiO2

Semiconductor material with narrow bandgap is an ideal photo-thermal conversion material because of its high absorption intensity in infrared region. Here, CuS/TiO2 composites were synthesized based on UV-responsive TiO2 compound with narrow bandgap semiconductor material CuS for CO2 conversion under full-spectrum irradiation. The experimental results showed that 2% CuS/TiO2 exhibited higher photocatalytic CO2 reduction efficiency due to the solar induced photo-thermal synergistic effect. CuS can absorb and convert infrared light into heat energy, which promotes the utilization range of sunlight for CO2 conversion. In-situ Fourier transform infrared spectroscopy (FT-IR) was used to explain the photocatalytic mechanism at the molecular level. This work suggested a feasible way for integrated utilization of solar energy by narrow bandgap semiconductor compounds with TiO2 to convert CO2.