C-N-S-TiO2光催化剂的制备、表征及其性能

以钛酸四丁酯为钛源、功能生物小分子胱氨酸为掺杂剂,采用溶胶-凝胶法同步合成了C-N-S-TiO2光催化剂,利用XRD、XPS、FT-IR和DRS等测试技术对样品的结构及物化性能进行了表征。XRD和DRS分析表明,共掺杂抑制了TiO2晶粒的生长,提高了晶相转变温度,且C-N-S-TiO2样品的吸收带边明显"红移",光吸收范围一直延长至800 nm左右。XPS分析结果显示,C-N-S-TiO2样品表面产生了杂质能级,C、S元素分别取代部分晶格Ti4+以CO23-和S6+形式存在;而N峰呈宽化状态,以O—Ti—N和Ti—O—N键存在,且样品表面羟基含量明显增加。以罗丹明B染料为模型污染物,考察了该催化剂的可见光催化活性。结果表明,与P25 TiO2比较,C-N-S-TiO2光催化剂活性得到改进,C-N-S-TiO2光催化剂在470～800 nm波长下辐射120 min后对罗丹明B的降解率可高达83%。

Synthesis and Characterization of C-N-S-tertiary Doped TiO2 Photocatalyst and Its Photocatalytic Activity

A visible-light responsible non-metal C-N-S-tertiary doped TiO2 was synthesized by a sol-gel process using Ti(OC4H9)4 and functional biology organic cystine as raw materials.The obtained photocatalysts were characterized by the means of X-ray powder diffraction(XRD),X-ray photoelectron spectroscopy(XPS),fourier transition infrared spectra(FT-IR),ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS).XRD showed that,by C,N and S tertiary-doping,the growth of TiO2 crystallite was restrained and the temperature of phase transformation from anatase to rutile of TiO2 was enhanced effectively.DRS showed the extension of light absorption edge in the range of visible-light was up to 800 nm.XPS analysis revealed that C and S existing on the surface of TiO2 photocatalyst was the state of CO2-3 and S6+,respectively.Nitrogen species could be ascribed to the form of N—Ti—O and Ti—O—N.And more hydroxyl groups were found on the C-N-S tertiary doped catalyst.The photocatalytic activities of the as-prepared photocatalysts were evaluated by degradation of Rhodamine B(RhB) in an aqueous suspension under visible light.It was found that C-N-S-tertiary doped TiO2 exhibited improved photocatalytic activity compared with that of P25 TiO2.Under the visible-light irradiation ranging from 470 to 800 nm for 2 h,an 83% removal rate of RhB could be achieved.