Ultrathin indium vanadate/cadmium selenide-amine step-scheme heterojunction with interfacial chemical bonding for promotion of visible-light-driven carbon dioxide reduction

The formation of interfacial chemical bonding in heterostructures plays an important role in the transport of carriers. Herein, we firstly prepared ultrathin InVO4 nanosheet (Ns) with a thickness of 1.5 nm. Diethylenetriamine-modified CdSe (CdSe-DETA) nanobelts are in-situ deposited on the surface of ultrathin InVO4 Ns to build a InVO4/CdSe-DETA step-scheme (S-scheme) heterojunction photocatalysts. The protonated DETA acts as an amine-bridge to promote the formation of a tight chemical bond at the interface of InVO4/CdSe-DETA, thereby promoting the transfer of carriers at the interface. For photocatalytic CO2 reduction, the rationally designed InVO4/CdSe-DETA S-scheme photocatalyst exhibits a remarkable CO generation rate of 27.9 µmol h-1 g-1 at 420 nm, which is 3.35 and 3.39 times higher than that of CdSe-DETA and InVO4 Ns, respectively. The new method by using interfacial chemical bonding to facilitate interfacial charge transportation provide a promising strategy for improve photocatalysis.