Mesoporous gold nanospheres via thiolate-Au(I) intermediates
Mesoporous gold nanospheres via thiolate-Au(I) intermediates
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DOI：
10.1039/c9sc01728c
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发表时间：
2019-07-14
期刊：
影响因子：
8.4
通讯作者：
Liu, Ben
中科院分区：
文献类型：
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作者：
Lv, Hao;Xu, Dongdong;Liu, Ben
介孔金 (mesoAu) 纳米球由于其三维 (3D) 内部介孔通道暴露了丰富的活性位点并促进电子/质量转移，因此支持增强的（电）催化性能。尽管已经通过电化学还原、合金化-脱合金和硬/软模板方法制备了各种多孔纳米结构金，但成功合成具有可定制尺寸和孔隙率的介观金纳米球仍然是一个巨大的挑战。在这里，我们描述了一种新颖的表面活性剂导向合成路线，通过使用 C22H45N+(CH3)(2)-C3H6-SH (Cl-) (C22N-SH) 两亲性表面活性剂作为介孔导向剂来制造具有 3D 互连介孔通道的介观金纳米球。 C22N-SH不仅可以将三价Au(III)Cl-4(-)自还原为单价Au(I)，还可以通过共价键形成聚合C22N-S-Au(I)中间体。这些C22N-S-Au(I)中间体促进自组装成球形胶束并抑制Au前驱体的移动性，从而通过原位化学还原实现介观Au纳米球的结晶成核和生长。该合成策略可以进一步扩展以定制介观金纳米球的尺寸/孔隙率和表面光学性质。介观金纳米球在甲醇电氧化中表现出显着增强的质量/比活性和改善的稳定性，表现出比无孔金纳米粒子和先前报道的金纳米催化剂更好的性能。该合成路线与其他长期建立的软模板方法明显不同，为生长具有所需纳米结构和功能的金属纳米晶体提供了新途径。
Mesoporous gold (mesoAu) nanospheres support enhanced (electro)catalytic performance owing to their three-dimensional (3D) interior mesochannels that expose abundant active sites and facilitate electron/mass transfers. Although various porous Nanostructured Au has been fabricated by electrochemical reduction, alloying-dealloying and hard/soft templating methods, successful synthesis of mesoAu nanospheres with tailorable sizes and porosities remains a big challenge. Here we describe a novel surfactant-directed synthetic route to fabricate mesoAu nanospheres with 3D interconnected mesochannels by using the amphiphilic surfactant of C22H45N+(CH3)(2)-C3H6-SH (Cl-) (C22N-SH) as the mesopore directing agent. C22N-SH can not only self-reduce trivalent Au(III)Cl-4(-) to monovalent Au(I), but also form polymeric C22N-S-Au(I) intermediates via covalent bonds. These C22N-S-Au(I) intermediates facilitate the self-assembly into spherical micelles and inhibit the mobility of Au precursors, enabling the crystallization nucleation and growth of the mesoAu nanospheres via in situ chemical reduction. The synthetic strategy can be further extended to tailor the sizes/porosities and surface optical properties of the mesoAu nanospheres. The mesoAu nanospheres exhibit remarkably enhanced mass/specific activity and improved stability in methanol electrooxidation, demonstrating far better performance than non-porous Au nanoparticles and previously reported Au nanocatalysts. The synthetic route differs markedly from other long-established soft-templating approaches, providing a new avenue to grow metal nanocrystals with desirable nanostructures and functions.