CuS -mediated two reaction systems enable biomimetic photocatalysis in CO2 reduction with visible light

The performances of heterogeneous catalysts can be effectively improved by optimizing the catalysts via appropriate structure design. Herein, we show that the catalysis of cuprous sulfide can be boosted by constructing the hybrid structure with Cu2S nanoparticles on amorphous CuSx matrix (Cu2S/CuSx). In the photocatalytic CO2 reduction under visible light irradiation, the Cu2S/CuSx exhibited a CO production rate at 4.0 µmol h−1 that is 12-fold higher than that of the general Cu2S catalyst. Further characterizations reveal that the Cu2S/CuSx has two reaction systems that realize the biomimetic catalysis, involving in the light reaction on the Cu2S nanoparticle–CuSx matrix heterojunctions for proton/electron production, and the dark reaction on the defect-rich CuSx for CO2 reduction. The CuSx matrix could efficiently activate CO2 and stabilize the split hydrogen species to hinder undesired hydrogen evolution reaction, which benefits the proton–electron transfer to reduce CO2, a key step for bridging the two reaction systems.