Fabrication, Characterization, and Photoelectric Application of Crystalline TiO2 Nanostructures

Abstract

Crystalline TiO2 nanostructures have been facilely grown on titanium foil via anodization and solvothermal processes and their morphological, structural, and optical properties have also been characterized. Photocatalytic and photovoltaic activities of TiO2 nanostructures have been measured using the degradation of an organic dye under Xe-lamp irradiation. Chapter 1 describes highly ordered and regularly porous anatase TiO2 nanotube arrays grown by anodizing Ti foil in mixed viscous solvents of ethylene glycol and glycerol. By changing the volume ratio of two solvents, we have controlled the structural and morphological properties of TiO2 nanotube arrays. Our prepared TiO2 nanotube arrays have been found to have enhanced (004) planes, which are reactive in catalysis reactions. Among our prepared samples, TiO2 nanotube arrays grown in 2:1 (v/v) ethylene glycol and glycerol have shown the best photocatalytic activity for the degradation of methylene blue and the highest photovoltaic conversion efficiency of 4.08%. Chapter 2 reports anatase-rutile cocrystalline TiO2 nanoblossoms fabricated via a one-step solvothermal process on Ti foil in mixed solvents of water and ethylene glycol. We have controlled the morphological, structural, and optical characteristics of TiO2 nanoblossoms easily by changing the volume ratio of water and ethylene glycol. Cocrystalline structures of our prepared TiO2 nanoblossoms act as nanoscale p-n junctions, which help to enhance the catalysis reactions. In particular, TiO2 nanoblossoms grown in the 1:1 volume mixture of water and ethylene glycol show the best photocatalytic activity.