CdSe quantum dots sensitized nanoporous hematite for photoelectrochemical generation of hydrogen

• CdSe QDs sensitization on hematite is explored for PEC hydrogen generation.
• Loading time of sensitizer to hematite films governs the PEC properties.
• Sensitization increased visible absorption and conductivity of the films.
• Band edge matching of hematite and CdSe QDs strengthen the photocurrent.

A novel system of CdSe quantum dots (QDs) sensitized porous hematite (α-Fe2O3) films has been investigated as a potential photoelectrode for hydrogen generation via photoelectrochemical (PEC) splitting of water. Before sensitization, nanoporous hematite thin films were prepared by spray pyrolysis. Characterizations for crystalline phase formation, crystallite size, absorption spectra, and flatband potential were carried out to analyze PEC data. Loading time of sensitizer to hematite thin films was found to be crucial in affecting its PEC properties. Film having sensitizer loading time as 42 h exhibited best photocurrent density of 550 μA cm−2 at 1.0 V versus SCE. Current study, for the first time, explores the possibility of using low band gap QDs sensitization on a low band gap film, hematite in PEC splitting of water.