X-ray photoelectron spectroscopic studies of anodically synthesized self aligned TiO₂ nanotube arrays: optimization of process parameters

Abstract

Selfaligned TiO₂nanotube arrays, compared to other TiO₂ nanostructures, have better electron transport properties that will enhance the efficiency of photo catalysis, hydrogen generation by photo-electrolysis and dye sensitized solar cells. Optimization of processparameters by tuning of electrochemical parameters allows the synthesis of TiO₂nanotube arrays of desired aspect ratio, wall thickness and morphology. In this study TiO₂nanotube arrays were synthesized at various electrochemical parameters and characterized using field emission scanning electron microscopy (FESEM), Fourier transform infra-red (FTIR) and X-rayphotoelectron spectroscopy (XPS). From the results of the study optimum potential range, electrolyte compositions and duration of anodization for the fabrication of smooth walled nanotube arrays of desired aspect ratio are delineated. Presence of surface hydroxyl groups and non-stochiometry in the as prepared and annealed TiO₂nanotubes were found from FTIR and XPS studies respectively, thus providing rationalization for the enhanced photo catalytic activity of TiO₂nanotube arrays.