Identifying the Site-Dependent Photoactivity of Anatase TiO2(001)-(1x4) Surface
Identifying the Site-Dependent Photoactivity of Anatase TiO2(001)-(1x4) Surface
复制标题
识别锐钛矿型 TiO2(001)-(1x4) 表面的位点依赖性光活性
DOI：
10.1021/acs.jpcc.7b07256
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发表时间：
2017
影响因子：
3.7
通讯作者：
Wang Bing
中科院分区：
文献类型：
--
作者：
Cheng Zhengwang;Tang Haoqi;Cui Xuefeng;Dong Shihui;Ma Xiaochuan;Luo Bin;Tan Shijing;Wang Bing
利用扫描隧道显微镜和程序升温脱附技术研究了甲醇在TiO 2（001）-（1×4）表面上的光催化反应。我们的研究结果表明，在还原表面的钛对缺陷的位置是光惰性的，但在再氧化表面的部分氧化的缺陷位是光活性的解离甲醇和甲氧基甲醛。理想的（1×4）晶格位置是光活性的，即使它们在热驱动反应中是不活跃的。甲醇（CD 3OH）在完美的晶格位置的光催化反应是由CD 3OH转化为各种其他氘代甲醇（CD 3 OD和CD 2 HOH）和少量的甲醛（CD 2 O）在紫外光照射后证明，与没有这样的转换反应在未照射的样品。CD 3 OD和CD 2 HOH的产生可归因于在紫外光照射期间或之后所产生的CD 2 O与H或D吸附原子之间的逆反应，这也导致最终产物中少量的甲醛。除了我们最近表征的位置依赖的热驱动反应之外，甲醇的位置依赖的光催化反应的鉴定可以提供对TiO 2（001）-（1×4）表面的活性和光活性的深入理解。
We here report our investigation on the photocatalytic reactions of methanol on the anatase TiO2(001)-(1×4) surface using scanning tunneling microscopy and temperature-programmed desorption. Our results show that in the reduced surface the Ti-pair defect sites are photoinactive, but in the reoxidized surface the partially oxidized defect sites are photoactive to dissociate methanol and methoxy to formaldehyde. The perfect (1×4) lattice sites are photoactive, even though they are inactive in thermally driven reaction. The photocatalytic reaction of methanol (CD3OH) at the perfect lattice sites is evidenced by the conversion of CD3OH to various other deuterated methanol (CD3OD and CD2HOH) and a small amount of formaldehyde (CD2O) after ultraviolet light irradiation, in contrast with no such conversion reaction in the nonirradiated sample. The production of CD3OD and CD2HOH can be attributed to the reverse reaction between the produced CD2O and the H or D adatoms during or after ultraviolet light irradiation, which also leads to the small amount of formaldehyde in final products. The identification of the site-dependent photocatalytic reactions of methanol, in addition to our recently characterized site-dependent thermally driven reactions, may provide an insightful understanding about the activity and photoactivity of the anatase TiO2(001)-(1×4) surface.