TiO2光催化剂的改性研究

采用浸渍法制备了掺杂Fe3+ ,用NH4 Cl提高单分散性并且用稀H2 SO4 表面修饰的TiO2 粉体光催化剂 ,考察了它与TiO2 在紫外光和日光作用下对直接耐晒黑G的降解效果。结果表明 ,以TiO2 干凝胶为母体 ,依次浸渍Fe3+ 、NH+ 4以及SO2 - 4所制备的粉体光催化剂Fe3+ /SO2 - 4/TiO2 在紫外光作用下降解效果比纯TiO2 高 2 .1倍 ,在日光作用下比TiO2 高 1 .9倍。X射线衍射分析表明 ,该法制备的TiO2 粉体中锐钛矿相占 1 0 0 % ,没有金红石相 ,平均晶粒粒径为 4nm ;红外吸收光谱分析表明 ,无论是纯TiO2 还是经过掺杂Fe3+ 、用H2 SO4 进行表面修饰后的TiO2 ,红外吸收光谱图基本相似 ,说明掺杂和表面修饰并没有极大地改变TiO2 的化学结构 ,光催化性能的提高归属于杂质能级的电子捕获陷阱作用、有效光成分增加和光生电子向反应物的迅速转移

Use of Photo-catalyst on TiO2

TiO_2 photocatalyst which was doped with Fe~(3+), surface modified with H_2SO_4, whose single expension was improved by NH_4Cl, was prepared using immersion method. Its degradation efficiency on direct fast black G under ultraviolet and sunlight was investigated. The results demonstrated that degradation efficiency of Fe~(3+)/SO~(2-)_4/TiO_2 which was in turn immersed Fe~(3+), NH~+_4, SO~(2-)_4, when regared TiO_2 dry gel as motherbody was higher 110% under ultraviolet and 90% under sunlight than that of TiO_2 respectively. XRD analysis indicated that anatase phase in TiO_2 was 100%, no rutile phase . The mean crystal diameter was 4nm. FTIR analysis indicated that two curves were similar, metal-ion doping and sulfur acid modification could not largely change the chemical structure of TiO_2 . Photocatalytic activity was promoted for electron-tractor effect of Fe~(3+), more effective light radiation and swift transfer of photogenerated electrons from the TiO_2 conduction band to dye.