Construction of S-scheme 0D/2D heterostructures for enhanced visible-light-driven CO2 reduction

Zero-dimensional quantum dots (QDs) and two-dimensional nanosheets represent two kinds of distinctive materials with unique properties. Here, we describe the fabrication of step-scheme (i.e. S-scheme) 0D/2D heterostructure with InVO4 QDs and g-C3N4 (CN) ultrathin nanosheets for photocatalytic CO2 reduction. The formation of S-scheme heterostructure facilitates the separation of electron-hole pairs and reduces the recombination of charge carriers. Moreover, the light-absorption edge of InVO4/CN is extended to 605 nm because of the strong visible light absorption of InVO4 QDs. The 0D/2D hybrid enables highly selective photocatalytic reduction of CO2 to CO (93.3 %) at a decent rate of 69.8 μmol g−1 h−1 under visible light irradiation. Density functional theory (DFT) results suggest that the formation of InVO4/CN heterostructure can enhance CO2 adsorption/activation, stabilize COOH* intermediates and allow rapid CO desorption as the major product. This study opens up a new possibility for construction of novel S-scheme heterostructure for photocatalytic applications.