Yang Yong, Ghildiyal Pankaj, Zachariah Michael R
Department of Chemical and Biomolecular Engineering , University of Maryland , College Park , Maryland 20742 , United States.
Department of Chemical and Environmental Engineering , University of California, Riverside , Riverside , California 92521 , United States.
Langmuir. 2019 Mar 5;35(9):3413-3420. doi: 10.1021/acs.langmuir.8b03532. Epub 2019 Feb 21.
Metal nanoclusters (1-10 nm) have drawn great attention because of their potential applications including energy storage, catalysis, nanomedicine, and electronic devices. However, manufacturing ultrasmall metal nanoparticles at high concentrations in an unaggregated state is not a solved problem. Here, we report an aerosol-based thermal shock technique for in situ synthesis of well-dispersed metal nanoclusters in on-the-fly graphene aerosols. A rapid thermal shock to the graphene aerosol has been used to nucleate and grow the metal nanoclusters with subsequent quenching to freeze the newly formed nanoclusters in the graphene aerosol matrix. A characteristic time analysis comparison with the experiment shows that the nanocluster formation is governed by nucleation and subsequent surface growth and that the graphene retards coagulation, enabling unaggregated metal nanoclusters. The method is generic, and we show the formation of sub-10 nm Ni, Co, and Sn nanoclusters. This continuous aerosol-based thermal shock technique offers considerable potential for the scalable synthesis of well-dispersed and uniform metal nanoclusters stabilized within a host matrix. As an example of potential application, we demonstrate very favorable catalytic properties.
金属纳米团簇（1-10纳米）因其在能量存储、催化、纳米医学和电子设备等方面的潜在应用而备受关注。然而，以高浓度、非聚集状态制造超小金属纳米颗粒仍是一个尚未解决的问题。在此，我们报告了一种基于气溶胶的热冲击技术，用于在飞行中的石墨烯气溶胶中原位合成分散良好的金属纳米团簇。对石墨烯气溶胶进行快速热冲击，使金属纳米团簇成核并生长，随后进行淬火，将新形成的纳米团簇冻结在石墨烯气溶胶基质中。与实验进行的特征时间分析比较表明，纳米团簇的形成受成核和随后的表面生长控制，并且石墨烯可延缓凝聚，从而形成非聚集的金属纳米团簇。该方法具有通用性，我们展示了亚10纳米镍、钴和锡纳米团簇的形成。这种基于气溶胶的连续热冲击技术为在主体基质中稳定地可扩展合成分散良好且均匀的金属纳米团簇提供了巨大潜力。作为潜在应用的一个例子，我们展示了非常良好的催化性能。
