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以适量聚乙烯吡咯烷酮(PVP)为保护剂,用H_2还原K_2PtCl_6水溶液高选择性(>80％)地合成了四面体形状的纳米铂晶粒(3～8 nm).采用透射电子显微镜(TEM)和紫外可见光谱仪(UV-Vis)研究了合成体系四面体形状纳米铂晶粒的合成过程.合成体系纳米铂胶体吸收光谱数据表明,纳米铂晶粒的生成经历了由快到慢的转变过程.TEM数据表明,绝大多数四面体形状纳米铂晶粒不是在成核和快速生长阶段,而是在小晶粒(<3 nm)的缓慢生长阶段生成.这些结果说明纳米铂的四面体形状很可能是通过晶粒生长中的表面晶面淘汰形成的.
Tetrahedron nano-platinum particles (3-8 nm) were synthesized with high selectivity (> 80%) using H 2 -reducing K 2 PtCl 6 aqueous solution with suitable amount of polyvinylpyrrolidone (PVP) as protective agent. Transmission electron microscopy (TEM) And UV-Vis spectroscopy were used to study the synthesis of tetrahedral platinum nanoparticles in the synthesis system.The absorption spectra of the nano-platinum nanoparticles in the synthesis system showed that the formation of nano-platinum particles underwent a transition from fast to slow. TEM data showed that the majority of tetrahedral platinum nanoparticles were not formed during the nucleation and rapid growth but at the slow growth phase of small crystallites (<3 nm) .These results indicate that the tetrahedral shape of nano-platinum is very May be formed by the elimination of the surface crystal plane during grain growth.