Thomas Andrew G, Jackman Mark J, Wagstaffe Michael, Radtke Hanna, Syres Karen, Adell Johan, Lévy Anna, Martsinovich Natalia
School of Materials and The Photon Science Institute and ‡School of Physics and Astronomy, The University of Manchester , Oxford Road, Manchester M13 9PL, United Kingdom.
Langmuir. 2014 Oct 21;30(41):12306-14. doi: 10.1021/la5032619. Epub 2014 Oct 8.
The adsorption of p-aminobenzoic acid (pABA) on the anatase TiO2(101) surface has been investigated using synchrotron radiation photoelectron spectroscopy, near edge X-ray absorption fine structure (NEXAFS) spectroscopy, and density functional theory (DFT). Photoelectron spectroscopy indicates that the molecule is adsorbed in a bidentate mode through the carboxyl group following deprotonation. NEXAFS spectroscopy and DFT calculations of the adsorption structures indicate the ordering of a monolayer of the amino acid on the surface with the plane of the ring in an almost upright orientation. The adsorption of pABA on nanoparticulate TiO2 leads to a red shift of the optical absorption relative to bare TiO2 nanoparticles. DFT and valence band photoelectron spectroscopy suggest that the shift is attributed to the presence of the highest occupied molecular orbitals in the TiO2 band gap region and the presence of new molecularly derived states near the foot of the TiO2 conduction band.
利用同步辐射光电子能谱、近边X射线吸收精细结构（NEXAFS）光谱和密度泛函理论（DFT）研究了对氨基苯甲酸（pABA）在锐钛矿型TiO₂(101)表面的吸附情况。光电子能谱表明，该分子在去质子化后通过羧基以双齿模式吸附。吸附结构的NEXAFS光谱和DFT计算表明，氨基酸单层在表面有序排列，环平面几乎垂直。pABA在纳米TiO₂上的吸附导致光吸收相对于裸TiO₂纳米颗粒发生红移。DFT和价带光电子能谱表明，这种红移归因于TiO₂带隙区域中最高占据分子轨道的存在以及TiO₂导带底部附近新的分子衍生态的存在。
