Improved charge transportation at PbS QDs/TiO2 interface for efficient PEC hydrogen generation

Abstract

The effect of lead sulfide (PbS) quantum dots (QDs) on the photoelectrochemical properties of TiO₂ with a varied number of SILAR cycles has been investigated. The study has also highlighted physical processes including band alignment, charge recombination and transportation for a PbS QDs/TiO₂ interface. The inclusion of PbS QDs underneath TiO₂ thin film has significantly enhanced the PEC response due to a higher number of photogenerated charge carriers along with the efficient separation and facilitation of these carriers towards their respective electrodes. The uniqueness of the work lies in the high stability of the system as PbS QDs lie beneath the TiO₂ thin film, compared to the commonly used QDs sensitization over metal oxide, along with a good photoresponse.