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在预先制备的Au胶体溶液中,以聚乙烯吡咯烷酮(PVP)为保护剂用氢气还原K2PtCl6合成了以Au为核心,以Pt为壳层的“核@壳”结构(Au@Pt)纳米颗粒.对样品进行了UV-Vis表征,结果显示,Au胶体特有的表面等离激元吸收峰强度随着K2PtCl6还原量的提高而递减;TEM检测表明,胶体溶液中金属纳米颗粒的尺寸由于PtCl62?的还原(生成Pt原子)而明显增大,预示着Pt原子在Au胶粒表面沉积形成了厚度均匀的壳层.样品的XPS检测结果也清楚地揭示,随着样品中Pt比例的提高,Au谱峰的强度减弱;并且当Pt︰Au原子比增加至2︰1时,Au谱峰完全消失,表明在颗粒表层形成了完整的Pt壳层,即此时的金属颗粒具有Au@Pt纳米结构.
In pre-prepared Au colloidal solution, K2PtCl6 was reduced by hydrogen gas with polyvinylpyrrolidone (PVP) as protective agent to synthesize Au @ Pt nanoparticles with Au as the core and Pt as the shell. The UV-Vis characterization of the sample showed that the specific surface plasmon peak absorption intensity of Au colloid decreased with the increase of K2PtCl6 reduction. The TEM results showed that the size of the metal nanoparticles in the colloidal solution was as high as that of PtCl62 (Pt atom is formed), which indicates that the Pt atom is deposited on the surface of the Au colloid to form a shell with a uniform thickness.The results of XPS also clearly reveal that with the increase of the Pt content in the sample, the Au spectrum The intensity of the peak weakened; and when the atomic ratio of Pt: Au was increased to 2: 1, the peak of Au disappeared completely, indicating that a complete Pt shell was formed on the particle surface, that is, the metal particles had Au @ Pt nanostructures.