Study On The Preparation And Photocatalytic Activity Of Composite Ti-Based Nanotube

TiO₂ nanotube arrays have good application prospects due to the highly ordered nanotube array structure in the field of photocatalysis. However,they have photocatalytic activity only under UV light, solar energy utilization ratio is low (less than 5%). This work aim is expanding TiO₂ nanotube array spectral response range, prepareing thin composites film that have the visible-light photocatalytic activity. First, the highly ordered TiO₂ nanotube arrays are prepared by secondary anodic oxidation; Secondly, using impregnation-photoreduced method, TiO₂ nanotube-based thin film with the visible light absorption were prepared through loading Cu₂O, AgI and other photocatalytic materials; Finally, the morphology, structure, element valence state of nanotube composites materials were tested by XRD, UV-vis, XPS, SEM, EDAX, HRTEM and other methods.Cu₂O/TiO₂ nanotubes that were prepared in Ethanol system or water system, have the absorption in the visible region, Cu₂O/TiO₂ nanotubes that were prepared in water system, Cu₂O were loaded at the surface of TiO₂ nanotubes; And in ethanol system, Cu₂O were loaded inside TiO₂ nanotubes. The content of Cu₂O that loaded on TiO₂ nanotubes in ethanol system is much higher than in the water system. In the Cu₂O/TiO₂nanotubes, Ti was existence by Ti4 + in the valence, Cu was existence by Cu + in the valence. Cu₂O/TiO₂ nanotubes that were prepared in ethanol system, the rate of the degradation of methyl orange increased constantly with the ratio of ethanol and water increased, when the ethanol content was 100%, Cu₂O/TiO₂ nanotubes have the highest photocatalytic activity. Ag/AgI/TiO₂ nanotubes were prepared by using multiple dipping. SEM results indicated the surface of TiO₂ nanotubes were loaded a large number of particles, Howver,Ag and AgI particles were loaded without damage TiO₂ nanotubes'appearance. XRD analysis that the characteristic peaks ofβ-AgI have emerged, while,XPS showed that Ag was existence with Ag0,and I was existence with AgI. UV-vis indicated Ag/AgI/TiO₂ nanotubes have absorption in the visible region,.Through the photocatalytic degradation of methyl orange under visible light, we found TiO₂ nanotubes which was calcined under 500 degrees after dipping several times, has great photocatalytic activity.