Novel visible-light-driven CdIn2S4/mesoporous g-C3N4 hybrids for efficient photocatalytic reduction of CO2 to methanol

Photocatalytic conversion of CO2 into hydrocarbon fuels using semiconductor photocatalysts has attracted great attention, which is considered as a promising approach to resolve the energy shortage and greenhouse effect. In this work, ordered mesoporous g-C3N4 (mpg-C3N4) nanosheets supported CdIn2S4 nanocomposites were successfully fabricated by a hard-template combinated with hydrothermal method. The hybrids showed highly efficient photocatalytic activities for the reduction of CO2 to CH3OH under visible-light irradiation. The optimized CdIn2S4/mpg-C3N4 photocatalyst exhibited a high CH3OH-production rate of 42.7 μmol g−1 h−1 at a mpg-C3N4 content of 20 wt%. This rate was 1.8 times higher than that of pure CdIn2S4. The significant enhancement of photocatalystic activity was mainly ascribed to the increased CO2 adsorption capacity and the improved separation and transfer of photogenerated electron-hole pairs at the intimate interface of CdIn2S4/mpg-C3N4 heterojunctions. Furthermore, the hybrid photocatalysts displayed excellent stability under visible-light. A possible mechanism of enhanced photocatalytic activity of CdIn2S4/mpg-C3N4 composite on photocatalytic reduction of CO2 was also proposed. This work may provide some useful information for the future design and practical application of multifunctional hybrid photocatalysts in photocatalytic reduction of CO2.