Ag–Cu–Pt–Pd quadrometallic nanoparticles which small Pt and Pd nanoparticles were attached on the surface of AgCu Janus nanoparticles were firstly synthesized by sequential reduction of Pt and Pd precursor in the presence of Janus AgCu bimetallic nanoparticles as seeds in an aqueous solution. Even though there was a small amount of Cu2O on the surface, the synthesized nanoparticles were mainly composed of four independent metallic part, not alloy parts. By theoretical calculation and growth mechanism study, we found that different reducing rate between Ag+ and Cu2+ and sequential reduction of Pt and Pd precursors would be key roles for the formation of the quadrometallic nanoparticles.

中文翻译：

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Ag-Cu-Pt-Pd四金属纳米粒子的简便水相合成。

Ag-Cu-Pt-Pd四金属纳米粒子，其小Pt和Pd纳米粒子附着在AgCu Janus纳米粒子的表面，首先通过在Janus AgCu双金属纳米粒子作为水溶液的种子存在下顺序还原Pt和Pd前体来合成。即使表面上有少量的Cu2O，合成的纳米颗粒也主要由四个独立的金属部分组成，而不是合金部分。通过理论计算和生长机理研究，我们发现Ag +和Cu2 +之间不同的还原速率以及Pt和Pd前体的顺序还原将是形成四金属纳米粒子的关键作用。