ESR Investigation into the effects of heat treatment and crystal structure on radicals produced over irradiated TiO2 powder
ESR Investigation into the effects of heat treatment and crystal structure on radicals produced over irradiated TiO2 powder
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DOI：
10.1016/s1010-6030(97)00208-6
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发表时间：
1997-11-15
影响因子：
4.3
通讯作者：
Nosaka, Y
中科院分区：
文献类型：
--
作者：
Nakaoka, Y;Nosaka, Y
对在空气中不同温度下加热处理的锐钛矿型 TiO2 粉末在 77 K 辐射下进行了电子自旋共振测量。对于未处理的粉末，光生空穴被捕获在表面，形成Ti4+O-.Ti4+OH-自由基，而对于加热粉末，它们被捕获为Ti4+O2-Ti4+O-。表面的自由基。光生电子以Ti3+的形式被捕获在未加热粉末的表面，而它们被捕获在热处理粉末的内部。这些差异可以通过表面羟基的解吸以及伴随晶体生长的表面结构的变化来解释。金红石二氧化钛粉末没有检测到光产生的自由基，这可以解释这种晶体结构的低光催化活性。 (C) 1997 Elsevier Science S.A.
Electron spin resonance measurements were carried out at 77 K under irradiation for anatase TiO2 powders treated by heating at various temperatures in the air. For the untreated powder photoproduced holes were trapped at the surface forming Ti4+O-.Ti4+OH- radicals, while, for the heated powder, they were trapped as Ti4+O2-Ti4+O-. radicals at the surface. Photoproduced electrons were trapped as Ti3+ at the surface of the unheated powder, while they trapped at the inner part of the heat-treated powder. These differences could be explained by the desorption of surface hydroxyl groups and the change in the surface structure accompanied by the crystalline growth. No photoproduced radicals were detected for rutile TiO2 powder, which may explain the low photocatalytic activity of this crystalline structure. (C) 1997 Elsevier Science S.A.