Investigation of dopant and Ag plasmonic effect on alpha-Fe2O3 photoelectrode for photoelectrochemical water splitting activity

Abstract

The role of plasmonics in hematite nanostructures has been under investigation since the past few years. However, the effect of plasmonics on doped hematite structures is not yet well understood. Therefore, in this study, yttrium-doped alpha-Fe2O3 nanostructures were prepared by hydrothermal and polyol techniques as photo-electrodes for energy applications. The effect of the dopant on the morphology, structure, and optical properties was studied. In addition, the effect of plasmonic Ag nanowires as the bottom layer was investigated. Optical analysis revealed a reduced band gap with increasing dopant concentration. Photoelectrochemical water splitting studies revealed that with optimized doping (0.2 mol%), photoelectrodes reached the maximum photocurrent density. The maximum photocurrent density of 0.742 mA cm(-2) was achieved in an optimized sample with an Ag layer, and was 67 times that of a pure sample with a plasmonic layer. Optimum doping and the plasmonic effect significantly improved the photocurrent density and reduced the charge recombination rate.