Effective Functionalization of Disordered Oxide Lattices on Iron Particle Surfaces Using Mechanochemical Reactions
Effective Functionalization of Disordered Oxide Lattices on Iron Particle Surfaces Using Mechanochemical Reactions
复制标题
利用机械化学反应对铁颗粒表面无序氧化物晶格进行有效功能化
DOI：
10.1021/jp401655m
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
J. Tanaka
中科院分区：
文献类型：
--
作者：
S. Motozuka;M. Tagaya;H. Nishiyama;M. Nishikawa;T. Ikoma;T. Yoshioka;S. Samitsu;J. Tanaka
采用机械力化学方法研究了无序晶格铁氧化物在裸铁颗粒表面的表面功能化，以阐明氧化层的形成机理，并研究了不同状态的近表面模型.首先在氩气气氛下制备了球磨平衡时的均匀α-Fe颗粒。X射线衍射、拉曼光谱和X射线光电子能谱分析表明，球磨后的样品近表面层由两种氧化铁相（α-Fe 2 O3和Fe 3 O 4）通过氧原子扩散形成，α-Fe 2 O3主要生长在近表面。在初始反应中，电子自旋共振信号表明α-Fe_2O_3上形成了悬挂键。氧原子有效地诱导了局域晶格的无序化，形成氧化的Fe 3+团簇，几何畸变形成了悬挂键，分子轨道计算证实了这一点，从而解释了α-Fe 2 O3上未成对电子位的增加.结果表明，由于原子团簇与裸α-Fe晶格失配而产生的缺陷Fe 3+离子形成了含有氧原子和未成对电子的无序晶格，而这些氧原子和未成对电子是通过简单的机械力化学反应在近表面应变作用下诱导形成的.通过氧化的Fe颗粒表面的表面活化的图案将能够通过选择性氧插入以及深度氧化进行新颖的化学反应。
The mechanochemical surface functionalization of iron oxides with disordered lattices on bare iron (Fe) particles was investigated using simple milling processes to clarify the formation mechanism of the oxide layer and investigate the near-surface models with different states. The homogeneous α-Fe particles at the milling equilibrium were first prepared under an argon atmosphere. After the subsequent milling reaction of the particles with oxygen molecules, the surface analyses by X-ray diffraction and Raman and X-ray photoelectron spectroscopies revealed that the near-surface layers consisted of two iron oxide phases (α-Fe2O3and Fe3O4) through oxygen atom diffusion, and the α-Fe2O3was dominantly grown on the near surface. During the initial reaction, the signals from an electron spin resonance suggested the dangling bond formation on α-Fe2O3. The oxygen atoms effectively induce disordered lattices in the local area to form oxidized Fe3+clusters, and the geometric distortion formed the dangling bonds, which were theoretically supported by a molecular orbital calculation to elucidate the increase in the unpaired electron sites on the α-Fe2O3. Therefore, the defective Fe3+ions induced by the lattice mismatching between the clusters and bare α-Fe are found to form the disordered lattice that contains the oxygen atoms with unpaired electrons, which are successfully induced by the near-surface strain based on the simple mechanochemical reactions. The patterns of surface activation of the Fe particle surfaces by oxidization will be capable of novel chemical reactions by selective oxygen insertion as well as deep oxidation.