Promoted water splitting by efficient electron transfer between Au nanoparticles and hematite nanoplates: a theoretical and experimental study

Abstract

An ideal interface model combining a hematite nanoplate-based photoanode with Au nanoparticles (NPs) is proposed for elucidating the specific role of Au NPs in photoelectrochemical performances. The theoretical and experimental results reveal that Au/Fe₂O₃ nanoplates can lead to an enhanced localized electric field at the metal–semiconductor interface upon the formation of surface plasmon resonance and hot electrons, which can be injected into the conduction band of the semiconductor, thus improving the efficiency of the generation and separation of electron–hole pairs. As expected, the Au/Fe₂O₃ nanoplate-based photoelectrode possessed a higher carrier density and a photocurrent of 1.7 mA cm⁻² and 3.8 mA cm⁻² at 1.23 V and 1.5 V vs. RHE, which are nearly 5 times and 30 times larger than that of the Au/Fe₂O₃ nanocrystals and pristine Fe₂O₃ nanoplate-based photoelectrodes, respectively.