Self-assembled synthesis of PbS quantum dots supported on polydopamine encapsulated BiVO4 for enhanced visible-light-driven photocatalysis

A simple self-assembled method for the deposition of PbS quantum dots (PbS QDs) on the surface of polydopamine (PDA)-encapsulated BiVO4 nanoparticles is proposed to synthesize PbS@PDA/BiVO4 nanocomposite photocatalysts with the assistance of ultrasonication. In the PbS@PDA/BiVO4 nanocomposites that was designed to improve the charge separation efficiency, PDA served as a natural adhesive and a stabilizer that can help to prevent PbS quantum dots from agglomeration, and PbS quantum dots served as the multiple exciton donor. The photocatalytic degradation of glyphosate experiments indicated that PbS@PDA/BiVO4 exhibited the enhanced photocatalytic activity under visible light irradiation. As compared with that of BiVO4, PbS@BiVO4 and PDA/BiVO4, the photocatalytic activity of PbS@PDA/BiVO4 was improved by 3.03, 1.48 and 1.58 times, respectively. The enhanced activity of PbS@PDA/BiVO4 can be attributed to the rapid transport of a mass of photoelectrons generated by multiexciton generation from PbS quantum dots to the surface of BiVO4 and the enhanced charge separation efficiency of photogenerated charge carrier.