粉煤灰负载纳米TiO_2的微区分析及应用

Microanalysis of Fly Ash/TiO_2 and Its Application

粉煤灰的微结构和主要成分决定了粉煤灰的物理、化学性能,直接关系到粉煤灰的综合利用,为了拓展粉煤灰在环境治理方面上的应用,本文采用水法分离得到粉煤灰沉珠,以此为载体利用溶胶-凝胶法负载了纳米TiO2,并且利用XRD,SEM,EDS等手段对原灰、沉珠、负载TiO2的粉煤灰进行了物相、微结构及微区分析.结果表明:粉煤灰主要由莫来石和石英组成,具有多孔结构,其常量元素为Al,Si,K,Ca,Ti,Fe等;在实验条件下负载的TiO2为锐钛矿型,随负载层数的增加,表面的Ti含量升高.光催化降解实验表明:负载有纳米TiO2的粉煤灰有良好的光催化活性,负载层数、降解时间等均对降解率有一定的影响,在适宜的条件下可以使染料酸性黑10B的去除率达到约80%.

The micro-structure and major contents of fly ash decide its physical and chemical performance, which has great relationship to the comprehensive utilization. To extend the application of fly ash in environment treatment, in this paper, sinking beads of fly ash were separated by water, and used as supporter for loading TiO2 by Sol-Gel process. The phase composition, microstructure and x-ray microanalysis about fly ash, singing beads and fly ash/TiO2 were investigated by XRD, SEM and EDS. The results showed that fly ash consists mainly of mullite and quartz, it has porous structure, and its major elements is AI, Si, K, Ca, Ti, Fe. The film of TiO2 on fly ash under present conditions has anatase crystalline, the content of Ti on the surface of fly ash increases with the number of loaded TiO2 layer. The experiments of photocatalytic degradation of the dye Acidic Black 10B by fly ash/TiO2 show that fly ash/TiO2 has good photocatalytic activity, the number of loaded TiO2 layer and the reaction time have great effect on the decolorizing rate. The decolorizing rate of the dye Acidic Black 10B can reach to about 80 % under the appropriate conditions.