反萃沉淀法制备纳米二氧化钛及其光催化氧化特性研究  

Preparation of Nano-TiO_2 by Stripping Precipitation Method and Photocatalytic Performance

作　　者：张凌云[1,2] 管航敏[1] 黎汉生[2] 张东翔[2] 

机构地区：[1]合肥学院化学与材料工程系,安徽合肥230022 [2]北京理工大学化工与环境学院,北京100081

出　　处：《钢铁钒钛》2008年第4期7-13,共7页Iron Steel Vanadium Titanium

基　　金：国家自然科学基金项目(20506002);合肥学院自然科学资金资助项目(07KY006ZR)

摘　　要：以D2EHPA作为萃取剂,CCl_4为溶剂萃取TiO(NO_3)_2水溶液后,以氨的水溶液和乙醇溶液反萃含钛的萃取有机相,通过优化控制相间传质动态微乳液过程,可以获得纳米TiO_2的前驱体。采用SEM、XRD、Zeta电位仪等手段对TiO_2进行表征。研究表明,降低氨水浓度和制备温度、提高乙醇助剂浓度、改变煅烧温度均对催化剂性能产生显著影响。氨水和氨水-乙醇反萃制备的纳米TiO_2的最佳煅烧温度分别为350℃和450℃,氨水浓度以体积比为1:5,制备温度为17.5℃,助剂浓度越高有利于生成更小的催化剂颗粒。以亚甲基蓝为特征模拟物,探讨了催化剂晶粒粒径和颗粒粒度及不同TiO_2制备方式与光催化活性相互关系,表明采用氨水-乙醇反萃制备的TiO_2光催化活性最高,60 min污染物去除率在85%以上。Precursor of nano - TiO2 was prepared through stripping precipitation method with D2EHPA diluted by tetrachloride carbon as an extractant, and ammonia and ammonia- alcohol aqueous solution as a re - extractant and precipitator. This process was optimized by controlling mass transport process on the interfaces of microemulsions. Nano - TiO2 obtained was characterized by SEM, XRD, Zeta potential devices. The result showed that catalytic performance was distinctly influenced by lowering temperature and concentration of ammonia aqueous, increasing concentration of ethanol auxiliary agent and varying calcinating temperature of TiO2 sample. By stripping precipitation with ammonia and ammonia - alcohol, the optimum calcinating temperatures of TiO2 were adjusted at 350 ℃ and at 450 ℃ respectively. The temperature and the optimum concentration of ammonia aqueous were 17.5℃ and 1：5 respectively. The higher concentration of auxiliary agent was more beneficial to forming smaller and more uniform TiO2 particles. Compared with sol - gel method, directing precipitation method and stripping precipitation method with ammonia, this study showed that nano - TiO2 prepared by stripping precipitation with ammonia - alcohol had not only a small and uniform grain, but also a high efficient photocatalytic activity, and the removal efficiency of methylene blue illuminated for 60 min with TiO2 by stripping precipitation with ammoniaalcohol was above 85 %.

关 键 词：无机非金属材料 反萃沉淀法 纳米TIO2 光催化氧化 

分 类 号：O614.411[理学—无机化学] O643.36[理学—化学]