Department of Chemistry, University of Catania, and INSTM UdR of Catania, Viale Andrea Doria 6, 95125 Catania, Italy.
ChemSusChem. 2013 Jun;6(6):1031-6. doi: 10.1002/cssc.201300149. Epub 2013 Apr 22.
The functionalization of micro- and nano-sized metal-oxide powders offers many advantages because of their large surface areas and, therefore, the large number of functional molecules that can be grafted onto the grain surfaces. Porphyrin molecules on large band-gap semiconducting metal oxides represent key materials for many different optical and electronic applications. Herein, we have proposed a general two-step procedure for the functionalization of metal-oxide crystals with dye-sensitizers. In particular, we functionalized SnO₂ nanoparticles with a monolayer of the bifunctional trichloro[4-(chloromethyl)phenyl]silane. Then, a monolayer of 5,10,15,20-tetrakis(4-hydroxyphenyl)-21H,23H-porphyne was covalently bound to the silanized SnO₂ grains. IR, UV/Vis, and luminescence measurements were used for optical characterization. The measured footprint of the grafted porphyrin molecules indicated total surface coverage of the grains. The surface electronic characterization was performed by using X-ray photoelectron spectroscopy. Emission measurements revealed two strong bands at 664.1 and 721.0 nm that were attributed to the porphyrin monolayer assembled on the surface of the SnO₂ crystals.
功能化的微纳米尺寸的金属氧化物粉末由于其较大的表面积，因此可以接枝大量的功能分子，具有许多优势。在具有较大带隙的半导体金属氧化物上的卟啉分子代表了许多不同光学和电子应用的关键材料。在这里，我们提出了一种用染料敏化剂对金属氧化物晶体进行功能化的通用两步法。具体来说，我们用双功能三氯[4-（氯甲基）苯基]硅烷单层功能化了 SnO₂纳米粒子。然后，将 5,10,15,20-四（4-羟基苯基）-21H,23H-卟啉单层共价键合到硅烷化的 SnO₂颗粒上。使用红外、紫外可见和发光测量进行光学表征。测量的接枝卟啉分子的足迹表明了颗粒的总表面覆盖率。通过使用 X 射线光电子能谱进行表面电子特性分析。发射测量显示出两个位于 664.1nm 和 721.0nm 的强带，归因于组装在 SnO₂晶体表面的卟啉单层。
