A facile cation-exchange approach to 2D PbS/amorphous MoSx heterojunction composites with enhanced photocatalytic activity

Abstract Constructing heterojunction is one of the methods for improving the photocatalytic activity by restraining the electron-hole recombination. In this work, a simple cation-exchange approach was employed to grow amorphous MoS x (a-MoS x ) on PbS surface to fabricate PbS/a-MoS x heterojunction for the first time. The formation of a-MoS x has been confirmed by XRD, Raman, TEM, EDS and XPS analysis. PbS/a-MoS x composites showed improved light harvesting ability compared with pristine PbS. The optimized composite exhibited greatly enhanced photocatalytic activity using methylene blue as the target of elimination, and displayed a photocurrent about 9 times higher than pristine PbS due to the efficient separation of photogenerated electron-hole pairs.