化学还原法合成Cu纳米粒子（英文）

Synthesis of Cu nanoparticles by chemical reduction method

通过室温化学还原合成Cu纳米粒子(CuNPs)。采用硼氢化钠还原Cu^2+离子,并用聚乙烯吡咯烷酮进行稳定化处理。考察还原剂/前驱体盐(RA/PS)比值的变化对CuNPs粒径和形貌的影响。利用紫外-可见光谱(UV-Vis)、X射线衍射(XRD)、扫描电镜(SEM)和透射电镜(TEM)对合成的材料进行表征。UV-Vis光谱显示,569nm处存在一CuNPs的等离激元峰;另一峰位于485nm处,为Cu2O的特征峰。XRD分析表明,合成的材料为fcc-Cu相,并含有少量的fcc-Cu2O化合物。SEM和TEM研究显示,当RA/PS比值为2.6时,得到粒径约7nm的半球形CuNPs微粒。过量的聚乙烯吡咯烷酮稳定剂对于防止CuNPs的氧化至关重要。另一方面,当RA/PS比在2.0~1.84范围内时,获得较大粒径的多面体形Cu2O颗粒,最大粒径可达150nm。此外,在RA/PS比为1.66时,得到在其尖端具有量子限域效应的星形Cu2O粒子。

Cu nanoparticles (CuNPs) have been synthesized through an easy route by chemical reduction at room temperature. The Cu^2+ ions were reduced and stabilized with sodium borohydride and polyvinylpyrrolidone, respectively. The effect of the variation of the reducing agent/precursor-salt (RA/PS) ratio on the size and morphology of the CuNPs was evaluated. The synthesized material was studied by ultraviolet-visible (UV-Vis) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The UV-Vis spectra showed a CuNPs plasmon peak at 569 nm and another peak belonging to Cu2O at 485 nm. XRD analysis showed the fcc-Cu phase with a small amount of fcc-Cu2O compound. SEM and TEM studies displayed that small semispherical CuNPs of approximately 7 nm were obtained at the RA/PS ratio of 2.6. The excess of polyvinylpyrrolidone stabilizer played an essential role in preventing CuNPs oxidation. On the other side, Cu2O polyhedral particles with larger sizes up to 150 nm were identified in the RA/PS ratio range of 2.0-1.84. In addition, Cu2O particles having star morphologies with quantum confinement at their tips were obtained at the RA/PS ratio of 1.66.