CeO2@Au核壳结构纳米粒子的合成与性质研究

采用沉淀法制备了球形CeO2纳米粒子,将其作为核粒子溶液,然后向其中滴加四氯合金酸溶液,在CeO2胶体表面利用柠檬酸钠还原AuCl4]-离子,得到了CeO2@Au核壳结构纳米粒子。TEM分析表明,CeO2纳米粒子分散效果好,粒径为5 nm;CeO2@Au核壳粒子为球形,无团聚,平均粒径为15 nm。XRD分析表明,CeO2@Au核壳粒子为晶型结构,属于立方晶系,CeO2空间群为O5H-FM3M,Au的空间群为Fm-3m。UV-vis分析发现,CeO2@Au核壳粒子在300和520 nm处呈现出两个比较强的吸收峰,分别对应于CeO2胶体溶液的吸收峰和金粒子的表面等离子共振吸收峰。EDS分析了核壳结构CeO2@Au纳米粒子中存在Ce,O和Au 3种元素。XPS分析表明,Ce3d3/2和Au4f电子结合能与标准结合能相比发生了变化,说明CeO2与Au之间存在着相互作用。

Synthesis and Properties of CeO2 @Au Core-Shell Structure Nanoparticles

Spherical CeO2 nanoparticles were prepared by precipitation method.The CeO2@Au core-shell nanoparticles were synthesized by chemical reduction of AuCl4]-on the surface of as-prepared CeO2 colloids using the sodium citrate as reducing agent.The TEM images showed that the CeO2 nanoparticles were well dispersed and the particle diameter was about 5 nm.The CeO2@Au core-shell nanoparticles had perfectly spherical shape with a narrow size distribution,non-agglomeration and the average particle size was about 15 nm.According to the XRD results,the CeO2@Au core-shell was crystalline and cubic in structure with space group O5H-FM3M of CeO2,space group Fm-3m of Au.The UV-vis results demonstrated that the two strong absorption spectrum were observed corresponding to the surface plasma band of the respective metal oxide and metal(viz.300 nm for CeO2 and 520 nm for Au in CeO2@Au core-shell nanoparticles).The EDS analysis confirmed the presence of Ce,O and Au elements in core-shell structured CeO2@Au nanoparticles.According to the difference of Ce3d3/2 and Au4f orbital electron binding energy in XPS between experimental binding energy and standard binding energy,it could be inferred that there existed an interaction between Au and CeO2.