Construction Of TiO₂ Micro-nano Structures And Their Photocatalytic Properties

In this paper,mixed phase TiO₂,mixed phase Ag/TiO₂ and mixed phase sodium titanate with 3D hierarchical structures have been successfully synthesized by using titanium???sulfate as salt sources in the presence of hydrochloric acid,glycol,hydrogen peroxide and sodium hydroxide.The crystals and morphologies of the obtained samples were characterized by using XRD and SEM.The optical properties of the obtained samples were characterized by using DRS and PL.The properties of as-prepared samples have been investigated,such as photocatalytic decomposition of organic dyes and photocatalytic decomposition of water into hydrogen.The specific contents and results are as follows:1.Mixed phase TiO₂ with three-dimensional structures were synthesized by a one-step hydrothermal method and characterized by scanning electron microscopy?SEM?,X-ray powder diffraction?XRD?,etc.The photocatalytic activities of TiO₂ samples were evaluated by the photocatalytic degradation of organic pollutants.The results showed that the obtained TiO₂ samples under different contents of HCl consisted of anatase/ rutile mixed phase.But their catalytic activities are different because of their different mass ratios of anatase and rutile.2.Ti O2 carrier was synthesized via hydrothermal method and characterized by scanning electron microscopy?SEM?.Then,the mixed phase Ag/TiO₂ samples were synthesized using different incorporation methods and characterized by X-ray powder diffraction?XRD?.The photocatalytic activities of the samples were evaluated by the photocatalytic degradation of methylene blue and hydrogen production.The effects of different loading methods and the content of doped Ag on the photocatalytic activity of the mixed phase Ag/TiO₂ were investigated.The results showed that mixed phase Ag/Ti O2 samples synthesized via a one-step hydrothermal method exhibited higher photocatalytic activity.The photocatalytic activity of Ag/TiO₂ increases at first with the growing amounts of Ag and then decreases after the optimal loading level.3.Precursors were synthesized via hydrothermal method and three-dimensional structures of Na0.23TiO₂/Na2Ti3O7 micro-nano-balls were successfully obtained after the calcination of precursors.The samples were characterized by SEM,XRD,UV-Vis diffuse reflection spectroscopy and N2 adsorption-desorption.The photocatalytic activities of samples were evaluated by the performance of photocatalytic hydrogen production.