Fe/SiO2核壳复合粒子表面的XPS谱研究

采用XPS技术研究了Fe/SiO2核壳复合粒子的表面化学成分和电子结构。结果表明,表面化学成分仅由Si和O元素组成,表面Si存在4种电子结构,表面O存在5种电子结构。表面硅4种电子结构的Si2p电子结合能及归属为:102.91eV(51.18%)为Q4硅[Si(OSi)4],102.15eV(23.23%)为Q3硅[Si(OSi)3OH],103.98eV(18.70%)为Q2硅[Si(OSi)2(OH)2],101.35eV(6.89%)为Q1硅[Si(OSi)(OH)3];表面氧5种电子结构的O1s电子结合能及归属为:532.85eV(52.07%)为Q4硅基团中的氧,531.80eV(19.93%)为Q3硅基团中的氧,533.90eV(17.09%)为Q2硅基团中的氧,534.75eV(7.65%)为Q1硅基团中的氧,530.55eV(3.26%)为与金属铁核相互作用的氧。531.80和530.55eV的氧原子数(19.93% 3.26%=23.19%)与102.15eV的硅原子数(23.23%)非常相近,这不仅表明与金属铁核相互作用的表面氧为Q3硅基团中的氧,而且说明表面氧与金属铁核相互作用后O1s电子结合能会因为Fe给电子能力较大而降低。

XPS Study on the Surface of Fe/SiO2 Core-Shell Composite Particles

The surface chemical compositions and electron structures of Fe/SiO2 co re-shell composite particles were studied with X-ray photoelectron spectroscop y (XPS). The results show that the surface chemical compositions are only compos ed of Si and O elements, the surface Si element has four kinds of electron struc tures, and the surface O element has five kinds of electron structures. The binding energies of Si2p electron and corresponding interpretations of the surface Si element are:102.91eV(51.18%) for silicon in Q4 group[Si(OSi) 4],102.15eV(23.23%) for silicon in Q3 group[Si(OSi)3OH],103.98eV (18.70%)for silicon in Q2 group [Si(OSi)2(OH)2],101.35e V (6.89%) for silicon in Q1 group[Si(OSi)(OH)3].The binding e nergies of O1s electron and corresponding interpretations of surface O element a re:532.85eV(52.07%) for oxygen in Q4 group,531.80eV(19.93%) for oxygen in Q 3 group,533.90eV(17.09%) for oxygen in Q2 group,534.75eV(7.65%) for oxygen in Q1 group,530.55eV(3.26%) for oxygen interacted with iron core. The atom percent of oxygens with O1s electron binding energies of 531.80eV and 530.55eV(1 9.93% 3.26%=23.19%) is very close to that of silicon with Si2p electron bindin g energy of 102.15eV(23.23%). This not only indicates that the surface O elemen ts in Q3 group interacted with iron core, but also imply that the binding ener gy of O1s electrons reduces when the surface O element interacts with iron core due to the larger ability of providing electron of Fe element.