TiO_2锐钛矿晶化度对其光生电荷性质及光催化活性的影响  

Effects of anatase crystallinity on photoinduced charge properties and photocatalytic activity of nano-sized TiO_2

作　　者：栾云博[1] 薛连鹏[1] 屈宜春[1] 井立强[1] 王文欣[1] 南赫[1] 

机构地区：[1]黑龙江大学化学化工与材料学院功能无机材料化学教育部重点实验室,哈尔滨150080

出　　处：《黑龙江大学自然科学学报》2010年第1期87-90,120,共5页Journal of Natural Science of Heilongjiang University

基　　金：教育部新世纪优秀人才支持计划资助项目(NCET-070259);教育部科学技术研究重点项目(207027);黑龙江省杰出青年科学基金资助项目(JC200701)

摘　　要：采用溶胶-水热法合成掺杂La、Zn以及La和Zn共掺杂的纳米TiO2。重点调控纳米TiO2的热稳定性及改善锐钛矿相的晶化度,在维持与P25型TiO2具有相似晶相组成条件下,考察锐钛矿相晶化度对光生电荷分离及光催化活性的影响。结果表明,La或Zn离子的引入能抑制晶相转变过程,且前者的抑制作用明显大于后者,相转变温度从500℃升高至750℃。表面光电压谱证实,锐钛矿相的晶化度越高,光生电荷越易分离。虽然La或Zn的引入可以提高纳米TiO2单位面积上的光催化活性,但却不能超过P25的活性。此结果表明锐钛矿晶化度强烈影响光生电荷的性质和光催化活性。Un-doped,La-doped,Zn-doped and La-Zn-co-doped nano-sized TiO2 samples were prepared by sol-hydrothermal processes,aiming to controllably obtain different TiO2 samples with the similar phase composition,but with different anatase thermal stability and crystallinity.On the condition of similar phase composition to the P25 TiO2,the effects of the anatase crystallinity on photoinduced charge separation and photocatalytic activity of nanocrystalline TiO2 were mainly investigated.The results show that La doping or Zn doping can inhibit the phase transformation process of TiO2,and the former has much greater effect than the latter.The beginning temperature of phase chage is changed from 500 to 750 ℃ after doping La.The surface photovoltage responses well demonstrate that the increase in the anatase crystallinity is in favor of the separation of photoinduced electron-hole pairs,which is responsible for the result that the unit-surface-area photocatalytic activity of the as-prepared TiO2 crystallities is improved by doping La or Zn,in spite of still with lower activity than P25 TiO2.It is suggested that the anatase crystallinity has great effects on the photoinduced charge properties and photocatalytic activity of TiO2,and the surface photovoltage technique is an effective tool to reveal the separation situation of photoinduced charges of semiconductor photocatalysts.

关 键 词：TIO2 离子掺杂 锐钛矿晶化度 光生电荷性质 光催化 

分 类 号：O643[理学—物理化学]