Preparation of a ZnIn2S4–ZnAlOx nanocomposite for photoreduction of CO2 to CO

Solar-driven CO2 conversion into fuels and sustainable energy has attracted increasing attention around the world. However, the efficiency of the transformation remains relatively low due to the rapid recombination of photogenerated charge carriers. In this work, we prepared a ZnIn2S4–ZnAlOx nanocomposite for visible light driven CO2 reduction. The thin layered structure facilitated the photoinduced charge carrier separation and transfer, and also gave excellent adsorption ability towards CO2 molecules. Such a nanocatalyst exhibited excellent activity in visible-light driven CO2 reduction with a CO optimal formation rate of 1100 μmol g−1 h−1, which is 5 times that over bulk ZnIn2S4, and the CO/H2 ratio was increased from 0.2 over bulk ZnIn2S4 to 1.5 over the ZnIn2S4–ZnAlOx composite. In situ FT-IR experiments indicated that CO2 was reduced on ZnIn2S4–ZnAlOx following a COOH* pathway. This work gives insights into the mechanism of the photocatalytic CO2 reduction reaction and inspiration to construct novel heterostructure materials for application in energy and environmental catalysis.