Plasmon-enhanced photoelectrochemical water splitting using au nanoparticles decorated on hematite nanoflake arrays

Abstract

Hematite nanoflake arrays were decorated with Au nanoparticles through a simple solution chemistry approach. We show that the photoactivity of Au-decorated Fe2O3 electrodes for photoelectrochemical water oxidation can be effectively enhanced in the UV/Visible region compared with the bare Fe2O3. Au-nanoparticle-decorated Fe2O3 nanoflake electrodes exhibit a significant cathodic shift of the onset potential up to 0.6 V [vs. reversible hydrogen electrode (RHE)], and a two times increase in the water oxidation photocurrent is achieved at 1.23 VRHE. A maximum photocurrent of 2.0 mAcm-2 at 1.6 VRHE is obtained in 1m KOH under AM 1.5 (100 mWcm-2) conditions. The enhancement in photocurrent can be attributed to the Au nanoparticles acting as plasmonic photosensitizers that increase the optical absorption.