0D/1D Cu2-S/TiO2 S-scheme heterojunction with enhanced photocatalytic CO2 reduction performance via surface plasmon resonance induced photothermal effects

Improving the sunlight absorption capacity and the charge separation efficiency is of great significance for TiO2 based photocatalyst to achieve highly efficient CO2 photoreduction. Herein, we developed a novel 0D/1D Cu2-xS/TiO2 S-scheme photocatalyst via a facile solvothermal approach. The optimized 0D/1D Cu2-xS/TiO2 photocatalyst exhibited an outstanding CH4 production rate of 14.1 μmol•h−1, which was about 3.9 times higher than that of pristine TiO2. Density functional theory calculation and experimental analyses demonstrated that the S-scheme heterojunction structure dramatically improved the charge separation efficiency and the reduction ability of the hybrid photocatalyst. Profiting from the surface plasmon resonance effect of Cu2-xS, the Cu2-xS/TiO2 photocatalyst showed an obviously expanded light absorption range, displaying remarkable photothermal effect under full-spectrum light irradiation. Moreover, a possible mechanism of CO2 photoreduction over the Cu2-xS/TiO2 photocatalyst was investigated based on in-situ Fourier transform infrared spectra. Hence, this 0D/1D Cu2-xS/TiO2 S-scheme photocatalyst coupled with photothermal effect could provide some useful hints for designing a full-spectrum-responsive CO2 reduction photocatalyst.