Surface interactions betweenY2O3 nanocrystals and organic molecules -: An experimental and quantum-chemical study
Surface interactions betweenY2O3 nanocrystals and organic molecules -: An experimental and quantum-chemical study
复制标题
DOI：
10.1016/j.susc.2005.07.027
复制
发表时间：
2005-11-01
期刊：
影响因子：
1.9
通讯作者：
Ojamäe, L
中科院分区：
文献类型：
--
作者：
Pedersen, H;Söderlind, F;Ojamäe, L
通过实验和量子化学计算研究了Y2O3纳米晶与有机分子甲酸、二甘醇(DEG)和四甲氧基硅烷(TMOS)之间的表面相互作用，旨在阐明其吸附振动光谱和吸附结构等化学吸附特征。采用基于多元醇的胶体法和快速燃烧法进行纳米晶的合成。用X-射线粉末衍射仪、透射电子显微镜、傅立叶变换红外光谱和X射线光电子能谱对产物进行了表征。在量子化学计算中，用B3LYP杂化密度泛函从头算方法研究了甲酸、二甘醇和三氧化二胺在Y12O18团簇表面的化学吸附。从计算的振动光谱和实验的振动光谱比较，推测甲酸与Y2O_3的结合方式为桥式或双齿式。XPS和FT-IR实验表明，DEG在粒子表面发生了化学吸附。DEG化学吸附在Y_2O_3上的实验红外光谱符合量子化学计算中羟基脱质子的吸附模式。根据量子化学计算，甲酸的吸附能约为370kJ mol(-1)，DEG约为550kJ mol(-1)，TMOS约为60kJ mol(-1)。(C)2005 Elsevier B.V.保留所有权利。
The surface interactions between Y2O3 nanocrystals and the organic molecules formic acid, diethylene glycol (DEG), and tetramethoxy silane (TMOS), have been studied experimentally and by quantum chemical calculations with the intent to elucidate the chemisorption characteristics such as adsorbate vibrational spectra and adsorption structures. Nanocrystal synthesis was performed by a colloidal method based on polyols and by a rapid combustion method. The products were experimentally characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS).In the quantum chemical calculations, the B3LYP hybrid density functional ab initio method was used to study the chemisorption of formic acid, DEG and TMOS at the surface Of Y12O18 clusters. From a comparison of calculated and experimental vibrational spectra, the binding mode for formic acid on Y2O3 was inferred to be of bridge or bidentate type. The XPS and FT-IR experiments showed that DEG is chemisorbed on the particle surface. The experimental IR spectra of DEG chemisorbed on Y2O3 were consistent with an adsorption mode where the hydroxyl groups are deprotonated according to the quantum-chemical computations. The adsorption energy is of the order of 370 kJ mol(-1) for formic acid, 550 kJ mol(-1) for DEG, and 60 kJ mol(-1) for TMOS, according to the quantum chemical calculations. (c) 2005 Elsevier B.V. All rights reserved.