TiO_2/ACF的Sol-Gel法制备及其对甲基橙的去除历程  

A new method of preparing TiO_2/ACF via solgel and its degradation mechanism for methyl orange

作　　者：孙剑[1] 刘守新[1] 

机构地区：[1]东北林业大学材料科学与工程学院,哈尔滨150040

出　　处：《安全与环境学报》2011年第1期19-24,共6页Journal of Safety and Environment

基　　金：黑龙江省杰出青年基金项目(JC200801);国家自然科学基金项目(30771692)

摘　　要：采用溶胶-凝胶法制备了TiO_2/ACF复合材料。采用SEM、低温液氮吸附对TiO_2/ACF复合材料的结构进行表征。以甲基橙为模型物考察TiO_2/ACF对液相有机污染物的去除性能。通过液相色谱-质谱联用技术(HPLC-MS)检测紫外光照射下TiO_2/ACF和TiO_2去除甲基橙过程中中间产物的种类与分布。结果表明:随着涂覆次数增加,复合材料比表面积下降,TiO_2涂层变厚、开裂,部分TiO_2脱落;煅烧温度决定TiO_2晶型结构和晶粒尺寸。涂覆2次、煅烧温度450 ℃所得TiO_2/ACF具有最高催化活性,100 min内对甲基橙的去除率高达100%,且循环使用5次后对甲基橙的去除率仍可达83.4%。ACF的负载减少了甲基橙去除过程中中间产物的种类和含量。在以TiO_2为光催化剂时检测到3种中间产物,甲基橙主要经过中间产物的路径被降解;而在TiO_2/ACF上以直接光催化降解为主,中间产物种类、数量均低于TiO_2。Abstract： The present paper is to introduce a via sol-gel method of preparing TiO2/ACF composite and the degradation mechanism for methyl orange. In order to develop the method of preparing the composite, we adopted the scanning electronic microscopy （SEM）, N2 （77 K） adsorption and X-ray diffraction to identify the characteristics of the composites and Methyl orange（MO） in addition to developing the compound model for testing the organic removal activity and HPLC-MS used for intermediate detection. The results of our study show that the calcination temperature and dip-coating times are the two principal influential factors on the activities of TiO2/ACF. With the increase of the dip-coating time length and the decrease of the surface area of TiO2/ACF as the TiO2 film turned to be thicker, then got split and eventually fell off. It was found that the complete anatase was formed into the sample calcinated at the temperature of 450℃ and the anatase phase transformation to futile at 750 ℃. The crystal size of TiO2 was found to decrease with the increase of ealcina-tions temperature. And, finally, the sample of TiO2/ACF-d50-2 exhibited its highest activity with the removing rate full-fledged to a hundred percent during the period of 100 rain. However, the methyl orange removing rate was found to increase only to 83.4% when the composite was recycled for five times. Moreover, when the composite was used to detect the three intermediate composites for TiO2, only one of then was found likely to be used for TiO2/ACF. Also, the intermediates for TiO2/ACF were also found much lower than that of TiO2. Furthermore, the methyl orange was found to get removed mainly through the intermediate photocatalysis of TiO2 and direct photocatalysis for TiO2/ACF. ACF loading can also be found to reduce the type and content of intermediates and effectively change the reaction mechanism.

关 键 词：环境科学技术基础学科 光催化 TIO2 ACF.Sol-Gel 复合材料 去除历程 

分 类 号：TB332[一般工业技术—材料科学与工程]