l-Arginine-Stabilized Highly Uniform Ag Nanoparticles Prepared in a Microwave-Induced Plasma-in-Liquid Process (MWPLP)

Microwave induced plasma in liquid has become a green and effective method for preparation of metallic nanoparticles (NPs). In our research, we have introduced yttrium oxide (Y2O3) coated stainless steel electrodes to address impurity problems of resulting NPs due to the loss of electrode materials. We have proposed using [Ag(NH3)2]+ complex as an alternative precursor and l-arginine as the stabilizing agent to synthesize highly uniform Ag NPs with an average diameter of around 5 nm. [Ag(NH3)2]+ complex was chosen as it can allow the reaction proceed at high pH for higher reaction yield compared with using AgNO3 whereas l-arginine can stabilize Ag NPs to attain highly uniform and small sizes. The influence of the selection of initial precursor on the reduction of metal precursor during the plasma irradiation, the particle size and size distribution of Ag NPs, and influence of the amount of l-arginine, were investigated.