摘要
在低于100℃温度条件下,采用溶胶-凝胶法以钛酸正丁酯为钛源,碘酸钾为碘源,制备了I掺杂纳米TiO2催化剂(I-TiO2),运用X-射线衍射(XRD)、透射电镜(TEM)及X-射线光电子能谱(XPS)等对催化剂进行表征,结果表明,TiO2及I-TiO2催化剂均为锐钛矿,I吸附并包裹在TiO2表面或以间隙进入的形式存在,并未进入TiO2晶格。通过在可见光照射下(λ>420 nm)以罗丹明B(Rhodamine B,RhB)的光催化降解为探针反应研究了在不同条件下制备催化剂的催化性能,结果表明,掺杂比为nI:nTi=0.05∶1,焙烧温度为400℃,降解介质条件pH=7时,I-TiO2光催化活性明显优于未掺杂的TiO2。光催化降解过程通过红外光谱(IR),总有机碳(TOC)跟踪测定,比较了TiO2掺杂前后降解RhB和对氯苯酚(4-CP)的光催化特性差异;同时采用苯甲酸荧光光度法跟踪测定体系中的氧化物种,表明在可见光下,I-TiO2光催化体系中产生.OH高活性氧化物种从而氧化降解目标化合物。
Iodine doped TiO2 and TiO2were prepared by sol-gel method using n-butyl titanate as titanium source and potassium iodate as iodine source, below 100℃ , and then characterized by XRD, TEM, and XPS. The results showed that TiO2 and iodate-TiO2 were both anatase. According to the characterization results, it was assumed that iodine was absorbed and wrapped on the TiO2surface or inset into interstices, but not entering in the TiO2 lattice. The degradation of Rhodamine B （RhB） and 4-chlorophenol （4-CP） as probe reactions were used to evaluate photocatalytic activity of catalysts prepared under different conditions. The results indicated that iodine-doped TiO2 calcined under 400℃ with molar ratio ni/nTi = 0. 05 ： 1 has remarkably higher photocatalytic activity than the undoped TiO2 at pH = 7 under the visible light irradiation （A 〉 420 nm）. The degradation process was studied by infrared spectrophotometry （IR） and total organic carbon （TOC）, and oxidation species were also detected utilizing benzoic acid by fluorescence analysis method, which showed that ~ OH was genera- ted to degrade organic compounds.
出处
《环境工程学报》
CAS
CSCD
北大核心
2013年第3期975-980,共6页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(20877048,21177072)
湖北省创新群体项目(2009CDA020)
湖北省高等学校优秀中青年科技创新团队计划(T200703)
关键词
二氧化钛碘掺杂光催化降解
Ti02
iodine-doped
photocatalysis
degradation
