Electrochemical synthesis and photoelectrochemical properties of grass-like nanostructured alpha-Fe2O3 photoanodes for use in solar water oxidation

Grass-like nanostructured alpha-Fe2O3 photoelectrodes were prepared for the first time through a simple cathodic electrodeposition method from an oxygenated aqueous solution of Fe3+ at room temperature without using surfactant, capping agents or any other additives. The alpha-Fe2O3 electrodeposits were characterized by X-ray photoelectron spectroscopy (XPS), energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), UV vis absorption and photoelectrochemical (PEC) techniques. The SEM and XRD results indicated that the as-deposited alpha-Fe2O3 are composed of single crystalline nanoleaves. The formation mechanisms of alpha-Fe2O3 have also been proposed based on a series of cyclic voltammetric and XPS studies. This new electrochemical method is expected to be a useful technique for the fabrication of single crystalline and photoactive alpha-Fe2O3 nanostructures directly onto the electrode surface, which is required in most applications, such as energy conversion and storage and sensors. (C) 2016 Elsevier Ltd. All rights reserved.