均相沉淀法制备S掺杂TiO_2纳米粉体及其光催化性能

Preparation and Photocatalytic Properties of S-Doped TiO_2 Nano-powders by Homogeneous Precipitation Method

以Ti(SO4)2为钛源和硫源,尿素为沉淀剂,采用均相沉淀法制备了S掺杂Ti O2纳米粉体。采用X射线衍射(XRD)、热重差热(TG-DTA)、傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)及能量弥散X射线能谱(EDS)等测试手段对其进行了表征,以亚甲基蓝为模拟污染物,评价了不同煅烧温度的粉体在可见光下的光催化活性。结果表明:制得的粉体颗粒粒径约为20 nm,颗粒大小均匀;掺杂硫取代了Ti O2中的晶格氧形成Ti-O-S键,硫含量约为0.1%(原子分数);350~600℃煅烧温度下的粉体均为锐钛矿型,且随着煅烧温度的升高,晶粒发育愈趋完整;S掺杂Ti O2纳米粉体具有较高的可见光催化活性,18 W白色荧光灯照射下,550℃煅烧样品对亚甲基蓝在2 h时降解率达80.67%。

S-doped TiO_2 nano-powders were prepared by a homogeneous precipitation method, using Ti(SO4)2 as titanium source and sulfur source, urea as precipitant. The powders were investigated by X-ray diffraction(XRD), thermogravimetric analysis-differential thermal analysis(TG-DTA), fourier transform infrared spectroscopy(FT-IR), transmission electron microscopy(TEM) and energy-dispersive X-ray spectroscopy(EDS) techniques. The photocatalytic activities of the powders were evaluated according to their photodegradation behavior of methylene blue under visible light. The results indicate that the obtained powders are uniform with particle size about 20 nm. Partial S atoms occupy O sites in the TiO_2 lattice to form Ti-O-S bonds, and the sulphur content is about 0.1 at.%. All the powders are anatase at the calcination temperature of 350~600 ℃, and the grain growth is increasingly complete with the increase of calcination temperature. In addition, the S-doped TiO_2 nano-powders have a fairy visible photocatalytic activity. Under 18 W white fluorescent lights, the samples calcinated at 550 ℃, degradating methylene blue in 2 h get the degradation rate of 80.67%.