Li Qian, Niu Wenxin, Liu Xingchen, Chen Ye, Wu Xiaotong, Wen Xiaodong, Wang Zhongwu, Zhang Hua, Quan Zewei
Department of Chemistry , Southern University of Science and Technology (SUSTech) , Shenzhen , Guangdong 518055 , P. R. China.
Center for Programmable Materials, School of Materials Science and Engineering , Nanyang Technological University , 50 Nanyang Avenue , Singapore 639798 , Singapore.
J Am Chem Soc. 2018 Nov 21;140(46):15783-15790. doi: 10.1021/jacs.8b08647. Epub 2018 Oct 31.
Although phase engineering of a noble metal, gold (Au), is of critical importance for both fundamental research and potential application, it still remains a big challenge in wet-chemical syntheses. In this work, we report the irreversible transformation from the hexagonal 4H to face-centered cubic ( fcc) phase in Au nanoribbons (NRBs) through high pressure treatment, which has not been discovered in metals. The relative percentage of 4H and fcc phases in the recovered Au NRBs depends directly on the peak pressure applied to the original 4H Au NRBs, enabling a phase engineering of Au nanostructures. Interestingly, compared to the pure 4H Au NRBs, the crystal-phase-heterostructured 4H/ fcc Au nanorods require less energy to complete the phase transition process with a lower transition pressure and in a narrower range. Finally, the atom-based transformation pathway during the 4H-to- fcc phase transition is revealed experimentally, which is supported by the first-principle calculations. This work not only demonstrates the stability of 4H Au nanostructure and the pressure-induced 4H-to- fcc transition mechanism but also provides a strategy for the phase engineering of noble metal nanostructures.
尽管贵金属金（Au）的相工程对于基础研究和潜在应用都至关重要，但在湿化学合成中仍然是一个巨大的挑战。在这项工作中，我们报告了通过高压处理，金纳米带（NRBs）中从六方4H相到面心立方（fcc）相的不可逆转变，这在金属中尚未被发现。回收的金纳米带中4H相和fcc相的相对百分比直接取决于施加到原始4H金纳米带上的峰值压力，从而实现了金纳米结构的相工程。有趣的是，与纯4H金纳米带相比，晶相异质结构的4H/fcc金纳米棒在较低的转变压力和较窄的范围内完成相变过程所需的能量更少。最后，通过实验揭示了4H到fcc相变过程中基于原子的转变途径，这得到了第一性原理计算的支持。这项工作不仅证明了4H金纳米结构的稳定性和压力诱导的4H到fcc转变机制，还为贵金属纳米结构的相工程提供了一种策略。
