Cu-BTC-confined synthesis of Cu-Cu2O-CuS nanojunctions embedded in a porous carbon matrix for remarkable photothermal CO2 conversion

Photothermal catalytic CO2 reduction into fuels using solar energy is an ideal strategy to reduce CO2 emission while producing value-added carbon compounds. However, developing low-cost and high-efficiency photothermal catalysts remains a significant challenge. Herein, photothermal hybrid catalysts (Cu-Cu2O-CuS@C), highly dispersed Cu-Cu2O-CuS nanojunctions (sub-10 nm) confined within a porous nitrogen-doped carbon octahedron matrix, are designed and fabricated through a simple pyrolysis-oxidation-sulfidation route using the prepared copper benzene-1,3,5-tricarboxylate (Cu-BTC) octahedra as the precursor. The prepared Cu-Cu2O-CuS@C sample exhibits a significant photothermal conversion effect, and more photons can be converted into thermal energy for promoting photoredox catalysis. Meanwhile, the formed Cu2O-CuS p-n nanojunction and Cu-Cu2O-CuS Schottky junction greatly accelerate charge transport, fundamentally expose more catalytic active sites and improve reactant adsorption. Thus more electrons could be excited and relaxed to participate in CO2 reduction reactions. These positive factors make the optimized Cu-Cu2O-CuS@C catalyst demonstrate remarkable photothermal catalytic activity toward CO2 conversion into CO (22.6 mu mol h(-1) g(-1)) and CH4 (3.06 mu mol h(-1) g(-1)). This work provides a rational strategy to fabricate efficient photothermal catalysts for solar energy utilization and conversion.