Superior photoelectrochemical properties of BiVO ₄ nanofilms enhanced by PbS quantum dots decoration

Novel BiVO ₄ nanofilms decorated with PbS quantum dots (PbS QDs/BiVO ₄ ) 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/BiVO ₄ nanofilms exhibit enhanced PEC activity compared with the obtained pure BiVO ₄ nanofilms. The photocurrent density is 0.68 mA cm ⁻² for the PbS QDs/BiVO ₄ photoelectrode at 0.5 V vs. Ag/AgCl electrode, which is much higher than that (0.36 mA cm ⁻² ) of the pure BiVO ₄ photoelectrode. The incident photon-to-current conversion efficiency (IPCE) of ∼5.9% at 370–450 nm for the PbS QDs/BiVO ₄ photoelectrode is almost two times higher than that (∼3%) of the pure BiVO ₄ photoelectrode. The deposition of PbS QDs on the surface of BiVO ₄ 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/BiVO ₄ photoelectrode. The present work demonstrates that the PbS QDs/BiVO ₄ nanofilms have potential applications in efficient PEC energy conversion system.