S掺杂宽光域响应Ti1-xSyO2光催化剂的制备及表征

以TiCl4和硫脲为主要原料, 采用酸催化水解法制得浅黄色S掺杂Ti1-xSyO2光催化剂. 以苯酚为模型物, 考察了Ti1-xSyO2在可见光区、紫外光区及太阳光下的催化活性. 采用XPS、DRS、XRD、FT-IR、SEM、低温氮物理吸附对光催化剂进行表征. 结果表明, 掺杂S以S6+形式置换TiO2晶格中的Ti4+, 适量S 掺杂的Ti1-xSyO2在可见光区、紫外光区及太阳光下均表现出较高的光催化活性.掺杂S 在TiO2表面形成新的能级结构, 使催化剂吸收红移至450-550 nm, 诱发可见光催化活性;紫外光照射下, 新形成的能级结构与体相TiO2形成复合半导体结构, 捕获光生空穴, 提高光生电子鄄空穴分离效率.同时, S掺杂可以改善TiO2的分散性, 增加其比表面积SBET并提高相转变温度.

Preparation and Characterization of S-doped Ti1-xSyO2 Photocatalyst with Wide Range Light Response

A yellowish Ti_(1-x)SyO_2 photocatalyst exhibiting high activity in wide light spectrum range was prepared by acid catalyzed hydrolysis method. Photocatalytic activity was investigated through the photocatalytic degradation of phenol under UV, artificial visible (Vis) and solar light irradiation, respectively. XPS, DRS, XRD, FT-IR, SEM, and N_2 adsorption were used for catalyst characterization. The results showed that cationic S6 was incorporated into TiO_2 lattice and substitutes a part of Ti4 . Ti_(1-x)SyO_2 with optimum S-doping exhibited the highest activity in both Vis and UV regions. The new band-gap formed by doped-S could induce a second adsorption edge (450-550 nm) which could be excited by Vis irradiation and induce Vis activity. Under UV irradiation, the new formed band-energy could accept holes generated by bulk TiO_2 and form a composite semiconductor structure, then improve hole-electron pairs separation. In addition, doped-S also benefited the dispersity of TiO2, increased SBET and retarded phase transformation.