NiO/TiO_2复合纳米管的水热制备及光催化性能

Preparation and Photocatalytic Properties of NiO/TiO_2 Nanotubes by Hydrothermal Method

采用水热法,制得了管径约为10～15nm、管长约为10～300nm、管壁上附着NiO纳米颗粒的TiO_2纳米管复合光催化剂(NiO/TiO_2).采用X射线衍射、透射电子显微镜、扫描电镜、X射线光电子能谱及紫外-可见漫反射光谱等技术对催化剂进行了表征;以甲基橙为模拟污染物,评价了纳米管的光催化活性.结果表明:NiO晶粒与TiO_2晶粒结合形成p-n异质结,有效地促进了光生电子和空穴的分离;NiO对可见光有强烈的吸收,使复合TiO_2纳米管在整个可见光区域均有很好的光吸收;以上两点使NiO/TiO_2纳米管可见光下的光催化活性大幅提升,500℃煅烧后纳米管对甲基橙1h分解比由纯TiO_2纳米管的7.0%提升至NiO/TiO_2纳米管的95.6%.

TiO2 nanotubes loaded NiO nanoparticles were prepared by hydrothermal method, which diameter and length are 10~15 nm and 10~300 nm, respectively. The nanotubes were characterized by X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy and uv-visible diffuse reflection spectrum. The photocatalytic activities of the nanotubes were evaluated according to their photodegradation behavior on methyl orange. The results show that TiO 2 and NiO grains are well integrated and form the p-n junction, promote the separation of photogenerated electron-hole pairs. NiO/TiO2 nanotubes have good absorption performance in the visible light region result from the strong visible light absorption of NiO. The above two factors lead to a significant increase in photocatalytic performance of NiO/TiO 2 nanotubes under visible light. Thereby, the 1 h photocatalytic degradation rate of methyl orange increased from 7.0% of pure TiO2 nanotubes to 95.6% of NiO/TiO2 nanotubes after calcination at 500℃.