Deposition of a ZnO Nanolayer on TiO2 Nanorods Nanoarrays with Tailored Thickness towards Boosted Photoelectrochemical Hydrogen Production Activity

Abstract

AbstractIn this study, one‐dimensional (1D) core‐shell structured TiO2@ZnO nanorod arrays have been synthesised by means of a simple hydrothermal method combining with subsequently ZnO atomic layer deposition (ALD). It was found that the thickness of the ZnO shell layers can be finely controlled with 20 nm, 30 nm, 40 nm and 50 nm by simply varying the deposition times. Photoelectrochemical (PEC) water splitting tests demonstrate that the TiO2@ZnO samples with 30 nm of ZnO layer yielded the highest photocurrent density of 1.24 mA/cm2 upon AM 1.5 illumination, which was about 1.55 times higher than that of pristine TiO2. The improved PEC activity is due to the enhanced interfacial charge‐separation and transportation based on the type II heterojunction as well as the unique 1D core‐shell structure.