Efficient Heterojunctions via the in Situ Self-Assembly of BiVO₄ Quantum Dots on SiC Facets for Enhanced Photocatalysis

Constructing a highly efficient heterojunction for photogenerated charges separation is essential to photocatalysis for solar energy conversion. In this work, we prepare an efficient photocatalyst, SiC/QD-BiVO4 composite, through in situ self-assembly method. This effective heterojunction is constructed by controlling QD-BiVO4 orientated deposition on certain facets of SiC. Efficient electron–hole separation is achieved by this heterojunction which resulted from the following two effects. One is that the selective distribution of QD-BiVO4 on SiC facets, rather than random deposition, reduces the transfer path length of photoexcited carriers. The other one is that the negative shift of the conduction band of BiVO4 quantum dots increases the electric potential difference in the built-in field, which accelerates the carriers’ transfer rate at the interface. Consequently, the O2 production is enhanced to 2096 μmol h–1 g–1 in SiC/QD-BiVO4 photocatalyst. Moreover, the degradation rate of RhB is doubled. Our work exhibits a rational route to prepare environmentally friendly photocatalytic material with potential applications.