Gold Nanoparticles in Novel Green Deep Eutectic Solvents: Self-Limited Growth, Self-Assembly & Catalytic Implications
Gold Nanoparticles in Novel Green Deep Eutectic Solvents: Self-Limited Growth, Self-Assembly & Catalytic Implications
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DOI：
10.1515/zpch-2014-0644
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发表时间：
2015-01-01
影响因子：
2.5
通讯作者：
Rademann, Klaus
中科院分区：
文献类型：
--
作者：
O'Neill, Maeve;Raghuwanshi, Vikram Singh;Rademann, Klaus
在这篇文章中，我们报道了在室温下分散在一种新的环保型深Eu 3+溶剂（DES;氯化胆碱和尿素）中的金纳米颗粒（AuNPs）的催化活性。采用低能量溅射沉积方法在DES表面上合成AuNPs。这是一种简单、经济和清洁的方法，用于通过自限制生长机制制备单分散金纳米颗粒。详细的小角X射线散射（SAXS），紫外-可见和透射电子显微镜（TEM）的研究表明，直径为5 nm的球形金纳米粒子的形成。此外，这些颗粒具有在DES表面自组装以及进入本体的强烈倾向。这是新一代金基催化剂的新补充。通过分析硼氢化钠存在下对硝基苯酚转化为对氨基苯酚的表观反应速率常数k（app），定量揭示了Au纳米粒子在DES中的催化活性。本文中报道的催化活性（k（app）= 0.34 s（-1））比Chirea等人早先报道的金纳米线网络的速率（k（app）= 0.030 min（-1））快得多[Langmuir，2011，27，3906]。与文献一致，我们解释了更高的催化活性在一个更大的表面积的金纳米粒子在非自组装状态。
In this article, we are reporting the catalytic activity of gold nanoparticles (AuNPs) dispersed in a novel eco-friendly Deep Eutectic Solvent (DES; choline chloride and urea) at room temperature. A low energy sputter deposition method is employed to synthesize AuNPs on the DES surface. This is a simple, economical and clean method for producing monodisperse gold nanoparticles by a self-limited growth mechanism. Detailed Small Angle X-ray Scattering (SAXS), UV-Vis and Transmission Electron Microscopy (TEM) investigations show the formation of spherical AuNPs of 5 nm in diameter. Moreover, these particles have a strong tendency to self-assemble at the DES surface as well as into the bulk. This is a new addition to a novel generation of gold based catalysts. The catalytic activity of Au nanoparticles in DES is revealed quantitatively by analyzing the apparent conversion reaction rate constant k(app) of para-nitrophenol to para-aminophenol in the presence of sodium borohydride. Catalytic activity reported in the present article is much faster (k(app) = 0.34 s(-1)) than the rate reported earlier (k(app) = 0.030 min(-1)) by Chirea et al. for gold nanowire networks [Langmuir, 2011, 27, 3906]. In agreement with the literature, we explain the higher catalytic activity in terms of a larger surface area of AuNPs in a non-self-assembled state.