Superior photoelectrochemical properties of BiVO4 nanofilms enhanced by PbS quantum dots decoration

摘要

Novel BiVO4 nanofilms decorated with PbS quantum dots (PbS QDs/BiVO4) have been successfully fabricated via a seed-mediated hydrothermal method and subsequent spin-coating process. The photoelectrochemical (PEC) tests demonstrate that the as-fabricated PbS QDs/BiVO4 nanofilms exhibit enhanced PEC activity compared with the obtained pure BiVO4 nanofilms. The photocurrent density is 0.68 mA cm(-2) for the PbS QDs/BiVO4 photoelectrode at 0.5 V vs. Ag/AgCl electrode, which is much higher than that (0.36 mA cm(-2)) of the pure BiVO4 photoelectrode. The incident photon-to-current conversion efficiency (IPCE) of similar to 5.9% at 370-450 nm for the PbS QDs/BiVO4 photoelectrode is almost two times higher than that (similar to 3%) of the pure BiVO4 photoelectrode. The deposition of PbS QDs on the surface of BiVO4 nanofilms extends their visible-light harvesting capability and accelerates charge separation of the photoelectrode, which are considered to be the main contributions to enhanced PEC activity of the as-prepared PbS QDs/BiVO4 photoelectrode. The present work demonstrates that the PbS QDs/BiVO4 nanofilms have potential applications in efficient PEC energy conversion system. (C) 2017 Published by Elsevier B.V.