Lv Hao, Xu Dongdong, Henzie Joel, Feng Ji, Lopes Aaron, Yamauchi Yusuke, Liu Ben
Jiangsu Key Laboratory of New Power Batteries , Jiangsu Collaborative Innovation Center of Biomedical Functional Materials , School of Chemistry and Materials Science , Nanjing Normal University , Nanjing , Jiangsu 210023 , China . Email:
Key Laboratory of Eco-chemical Engineering , College of Chemistry and Molecular Engineering , Qingdao University of Science and Technology , Qingdao 266042 , China.
Chem Sci. 2019 May 28;10(26):6423-6430. doi: 10.1039/c9sc01728c. eCollection 2019 Jul 14.
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 CHN(CH)-CH-SH (Cl) (CN-SH) as the mesopore directing agent. CN-SH can not only self-reduce trivalent Au(iii)Cl to monovalent Au(i), but also form polymeric CN-S-Au(i) intermediates covalent bonds. These CN-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 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.
介孔金（mesoAu）纳米球由于其三维（3D）内部介孔通道而具有增强的（电）催化性能，这些通道暴露了丰富的活性位点并促进了电子/质量转移。尽管已经通过电化学还原、合金化-脱合金化和硬/软模板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孔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CHN(CH)-CH-SH(Cl)(CN-SH)两亲表面活性剂作为介孔导向剂来制备具有3D互连介孔通道的介孔金纳米球。CN-SH不仅可以将三价Au(iii)Cl自还原为一价Au(i)，还能形成聚合物CN-S-Au(i)中间体共价键。这些CN-S-Au(i)中间体促进自组装成球形胶束并抑制Au前驱体的迁移，从而通过化学还原实现介孔金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孔金纳米球的尺寸/孔隙率和表面光学性质。介孔金纳米球在甲醇电氧化中表现出显著增强的质量/比活性和提高的稳定性，证明其性能远优于无孔金纳米颗粒和先前报道的金纳米催化剂。该合成路线与其他成熟的软模板方法明显不同，为生长具有理想纳米结构和功能的金属纳米晶体提供了一条新途径。
