Microwave synthesis of single-phase nanoparticles made of multi-principal element alloys
Microwave synthesis of single-phase nanoparticles made of multi-principal element alloys
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DOI：
10.1007/s12274-021-3893-y
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发表时间：
2021-10
期刊：
影响因子：
9.9
通讯作者：
Siyu Wu;Yuzi Liu;Yang Ren;Qilin Wei;Yugang Sun
中科院分区：
文献类型：
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作者：
Siyu Wu;Yuzi Liu;Yang Ren;Qilin Wei;Yugang Sun
通过快速加热/冷却封装在分散在油相（例如环己烷）中的胶束囊泡中的纳米金属，合成了具有单晶相的多主元素合金（MPEA）的金属纳米颗粒。闪速加热是通过金属选择性吸收微波脉冲，将金属快速加热成均匀的熔体来实现的。油相几乎不吸收微波并保持低温，可以快速淬火高温金属熔体，实现闪冷过程。包封在胶束囊泡中的水溶液中的肼可以同时还原包括 Au、Pt、Pd 和 Cu 在内的四种金属的前体离子。由此产生的金属有效地吸收微波能量，局部达到足够高的温度，从而将自身熔化成均匀的混合物。微波脉冲的持续时间对于确保还原的金属均匀混合至关重要，而油相的温度仍然较低，可以快速淬火金属并冻结合金纳米颗粒中的单相晶格。当适当的油包水胶束系统和适当的金属前体还原反应可用时，微波快速加热/冷却提供了一种合成多种金属组合的单相 MPEA 纳米颗粒的新方法。
Metal nanoparticles of multi-principal element alloys (MPEA) with a single crystalline phase have been synthesized by flash heating/cooling of nanosized metals encapsulated in micelle vesicles dispersed in an oil phase (e.g., cyclohexane). Flash heating is realized by selective absorption of a microwave pulse in metals to rapidly heat metals into uniform melts. The oil phase barely absorbs microwave and maintains the low temperature, which can rapidly quench the high-temperature metal melts to enable the flash cooling process. The precursor ions of four metals, including Au, Pt, Pd, and Cu, can be simultaneously reduced by hydrazine in the aqueous solution encapsulated in the micelle vesicles. The resulting metals efficiently absorb microwave energy to locally reach a temperature high enough to melt themselves into a uniform mixture. The duration of microwave pulse is crucial to ensure the reduced metals mix uniformly, while the temperature of oil phase is still low to rapidly quench the metals and freeze the single-phase crystalline lattices in alloy nanoparticles. The microwave-enabled flash heating/cooling provides a new method to synthesize single-phase MPEA nanoparticles of many metal combinations when the appropriate water-in-oil micelle systems and the appropriate reduction reactions of metal precursors are available.