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

Abstract

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–ZnAlO_x 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–ZnAlO_x composite. In situ FT-IR experiments indicated that CO₂ was reduced on ZnIn₂S₄–ZnAlO_x 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.