Self-assembled hematite (α-Fe2O3) nanotube arrays for photoelectrocatalytic degradation of azo dye under simulated solar light irradiation

Self-assembly aligned hematite (alpha-Fe2O3) nanotube arrays (alpha-Fe2O3 NTs) were successfully prepared on the Fe foils by a simple two-step electrochemical anodization method in NH4F organic electrolyte. The alpha-Fe2O3 NTs electrodes were characterized by field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, grazing incidence X-ray diffraction, UV-vis absorbance spectra, and X-ray photoelectron spectroscopy. The resulting alpha-Fe2O3 NTs showed a pore diameter of 40 nm, thickness of 2 mu m, and a minimum wall thickness of 10 nm. The systematic photoelectrochernical responses on the alpha-Fe2O3 NTs electrodes were presented. The maximum photoconversion efficiencies of 0.51% and 0.60% were collected at 0.3 V under illumination of visible light and simulated solar light (AM 1.5G), respectively. The photoelectrocatalytic (PEC) and photocatalytic (PC) activities of the alpha-Fe2O3 NTs electrodes were evaluated by degradation of azo dye. The significant PEG and PC performance indicated that the alpha-Fe2O3 NTs electrodes were an effective photoelectrode under visible light and simulated solar light illumination. (C) 2010 Elsevier B.V. All rights reserved.