Fabrication of a TiO2/Fe2O3 Core/Shell Nanostructure by Pulse Laser Deposition Toward Stable and Visible Light Photoelectrochemical Water Splitting

Here, we report the fabrication of TiO2/Fe2O3 core/shell heterojunction nanorod arrays by a pulsed laser deposition (PLD) process and their further use as photoelectrodes toward high-performance visible light photoelectrochemical (PEC) water splitting. The morphology, phase, and carrier conduction mechanism of plain TiO2 and TiO2/Fe2O3 core/shell nanostructure were systematically investigated. PEC measurements show that the TiO2/Fe2O3 core/shell nanostructure enhances photocurrent density by nearly 2 times than the plain ones, increases visible light absorption from 400 to 550 nm, raises the on/off separation rate, and delivers high stability with only a 3% decrease of current density for tests of even more than 14 days. This work provides a method to design an efficient nanostructure by combination of a facile hydrothermal process and high-quality PLD process to fabricate a clean surface and excellent crystallinity for charge separation, transfer, and collection toward enhanced PEC properties.