Department of Materials Science and Engineering 4, Friedrich-Alexander-University of Erlangen-Nuremberg, Martensstrasse 7, 91058 Erlangen, Germany.
Langmuir. 2010 Mar 2;26(5):3531-8. doi: 10.1021/la9032139.
Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and X-ray photoelectron spectroscopy (XPS) were used to study monolayers (ML) and thick films of porphyrin Zn-TESP (C(67)H(75)N(5)O(5)SiZn) attached to titanium dioxide (TiO(2)) substrates via silanization. Films on ideal hydroxyl-terminated silicon (SiO(2)) surfaces were used for comparison. ToF-SIMS and XPS spectra show that the type of adsorption varies depending on the thickness of the organic film, the preparation temperature, and the adsorption time. We show that the intensity of a molecular peak at mass 1121.5 u in ToF-SIMS can be used as a direct measure of the ratio of chemisorption/physisorption of Zn-TESP. On TiO(2), the amount of chemisorbed porphyrin can be increased by increasing the reaction temperature and time during the silanization process. On the SiO(2) reference, only chemisorbed species were detected under all investigated preparation conditions. The present work thus not only gives information on the Zn-TESP linkage to TiO(2) but provides a direct tool for generally determining the type of adsorption of monolayers.
飞行时间二次离子质谱（ToF-SIMS）和 X 射线光电子能谱（XPS）被用于研究卟啉 Zn-TESP（C(67)H(75)N(5)O(5)SiZn）通过硅烷化作用附着在二氧化钛（TiO(2)）基底上的单层（ML）和厚膜。使用理想的羟基终止的硅（SiO(2)）表面上的薄膜作为比较。ToF-SIMS 和 XPS 谱表明，吸附的类型取决于有机膜的厚度、制备温度和吸附时间。我们表明，在 ToF-SIMS 中质量为 1121.5 u 的分子峰的强度可以用作 Zn-TESP 的化学吸附/物理吸附比率的直接测量。在 TiO(2)上，通过增加硅烷化过程中的反应温度和时间，可以增加化学吸附卟啉的量。在 SiO(2)参考中，在所有研究的制备条件下仅检测到化学吸附物质。因此，本工作不仅提供了关于 Zn-TESP 与 TiO(2)连接的信息，而且还提供了一种用于一般确定单层吸附类型的直接工具。
