Saleem Faisal, Liu Guangyao, Liu Guigao, Chen Bo, Yun Qinbai, Ge Yiyao, Zhang An, Wang Xixi, Zhou Xichen, Wang Gang, Liao Lingwen, He Zhen, Li Lujiang, Zhang Hua
Department of Chemistry, City University of Hong Kong, Hong Kong, China.
Key Laboratory of Flexible Electronics (KLOFE) & Institute of Advanced Materials (IAM) & School of Flexible Electronics (Future Technologies), Nanjing Tech University, Nanjing, 211816, China.
Small Methods. 2024 Nov;8(11):e2400430. doi: 10.1002/smtd.202400430. Epub 2024 Jul 6.
Selective oxidative etching is one of the most effective ways to prepare hollow nanostructures and nanocrystals with specific exposed facets. The mechanism of selective etching in noble metal nanostructures mainly relies on the different reactivity of metal components and the distinct surface energy of multimetallic nanostructures. Recently, phase engineering of nanomaterials (PEN) offers new opportunities for the preparation of unique heterostructures, including heterophase nanostructures. However, the synthesis of hollow multimetallic nanostructures based on crystal-phase-selective etching has been rarely studied. Here, a crystal-phase-selective etching method is reported to selectively etch the unconventional 4H and 2H phases in the heterophase Au nanostructures. Due to the coating of Pt-based alloy and the crystal-phase-selective etching of 4H-Au in 4H/face-centered cubic (fcc) Au nanowires, the well-defined ladder-like Au@PtAg nanoframes are prepared. In addition, the 2H-Au in the fcc-2H-fcc Au nanorods and 2H/fcc Au nanosheets can also be selectively etched using the same method. As a proof-of-concept application, the ladder-like Au@PtAg nanoframes are used for the electrocatalytic hydrogen evolution reaction (HER) in acidic media, showing excellent performance that is comparable to the commercial Pt/C catalyst.
选择性氧化蚀刻是制备具有特定暴露晶面的中空纳米结构和纳米晶体最有效的方法之一。贵金属纳米结构中的选择性蚀刻机制主要依赖于金属组分的不同反应性以及多金属纳米结构独特的表面能。近年来，纳米材料的相工程（PEN）为制备独特的异质结构，包括异相纳米结构提供了新的机会。然而，基于晶相选择性蚀刻的中空多金属纳米结构的合成很少被研究。在此，报道了一种晶相选择性蚀刻方法，用于选择性蚀刻异相金纳米结构中非常规的4H和2H相。由于在4H/面心立方（fcc）金纳米线中Pt基合金的包覆以及4H-Au的晶相选择性蚀刻，制备出了轮廓清晰的阶梯状Au@PtAg纳米框架。此外，使用相同的方法也可以选择性蚀刻fcc-2H-fcc金纳米棒和2H/fcc金纳米片中的2H-Au。作为概念验证应用，阶梯状Au@PtAg纳米框架用于酸性介质中的电催化析氢反应（HER），表现出与商业Pt/C催化剂相当的优异性能。
