In this paper, novel TiO2/CeO2 core/shell heterojunction nanorod (NR) arrays were synthesized as photoanode for photoelectrochemical (PEC) water splitting via a simple and facial two-step hydrothermal approach. This synthesis route can obtain different amount of CeO2 nanoparticles by controlling the hydrothermal time and eventually achieve uniform TiO2/CeO2 core/shell nanostructures. The uniform TiO2/CeO2 core/shell heterojunction nanoarrays exhibit a markedly enhanced photocurrent density of 5.30 mA.cm(-2) compared to that of pristine TiO2 NR 1.79 mA.cm(-2) at 1.23 V vs. RHE in 1 M KOH solution. The superior PEC performance of the TiO2/CeO2 core/shell heterojunction is primarily due to much enhanced visible light absorption and appropriate gradient energy gap structure. This work not only offers the synthesis route for the novel TiO2/CeO2 core/shell heterojunction, but also suggests that this new core/shell heterojunction has a great potential application for efficient PEC water splitting devices. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.