【摘要】 由工业生产引起的铬污染是环境领域面临的一大挑战.二氧化钛（TiO₂）材料因其吸附催化的双重作用在铬的去除方面具有潜在应用前景.利用溶剂热法合成高指数晶面TiO₂{201},对其进行SEM、TEM、XRD及XPS表征,并用于Cr（Ⅲ/Ⅵ）的吸附及Cr（Ⅵ）的光催化还原,以达到从水体中去除铬的目的.所合成的TiO₂{201}为锐钛矿相,呈蒲公英状的层级结构. Langmuir吸附等温线结果表明,TiO₂{201}对Cr（Ⅲ）和Cr（Ⅵ）的最大吸附量分别为22. 7 mg·g-1和13. 2 mg·g-1,Freundlich模型拟合结果表明TiO₂{201}对Cr（Ⅲ）和Cr（Ⅵ）的吸附均易于进行,其1/n均小于0. 5.在紫外光照条件下,TiO₂{201}作为光催化剂可将毒性较强且吸附去除效果较差的Cr（Ⅵ）还原成Cr（Ⅲ）,并以Cr（OH）3及Cr2O3的形式沉淀在TiO₂表面,XPS表征结果进一步证实了表面沉淀的存在.为探明TiO₂{201}光催化还原Cr（Ⅵ）的机制,分别研究光生空穴淬灭剂（EDTA-2Na）和光生电子淬灭剂（KBr O3）对Cr（Ⅵ）还原效率的影响,证明Cr（Ⅵ）的还原是由光生电子引起.更多还原

【Abstract】 Chromium（ Cr） contamination caused by industrial manufacturing poses a severe challenge in the environment. Titanium dioxide（ TiO₂） has potential application in Cr removal due to its adsorption and photocatalytic performance. High-index TiO₂ with exposed { 201} facet was synthesized using the solvothermal method and characterized by SEM,TEM,XRD,and XPS. The adsorption of Cr（ Ⅲ/Ⅵ） and photocatalytic reduction of Cr（ Ⅵ） on TiO₂{ 201} was examined for the removal from water. The synthesized TiO₂{ 201} was constructed by a dandelion-like hierarchical structure. The adsorption isotherms of Cr（ Ⅲ） and Cr（ Ⅵ） on TiO₂{ 201}conformed to the Langmuir model,with maximum adsorption capacities of 22. 7 mg·g-1 and 13. 2 mg·g-1,respectively. The best fitted results from the Freundlich model show that the adsorption of Cr（ Ⅲ） and Cr（ Ⅵ） on TiO₂{ 201} were favorable with the parameter of 1/n less than 0. 5. The results of photocatalytic reduction show that TiO₂{ 201} can reduce Cr（ Ⅵ） to Cr（ Ⅲ） under UV irradiation,and Cr（ Ⅲ） was further precipitated on the surface of TiO₂ in the form of Cr（ OH）3 and Cr2 O3,which was evidenced by XPS characterization. To explore the mechanism of photocatalytic reduction of Cr（ Ⅵ）,the effect of scavengers for photogenerated holes（ EDTA-2 Na） and electrons（ KBr O3） on Cr（ Ⅵ） reduction was studied,and the results suggested that photogenerated electrons were the main reductant.更多还原