Microplasma-chemical synthesis and tunable real-time plasmonic responses of alloyed Au_xAg_1−x nanoparticles

Abstract

Tunable synthesis of bimetallic Au(x)Ag(1-x) alloyed nanoparticles and in situ monitoring of their plasmonic responses is presented. This is a new conceptual approach based on green and energy efficient, reactive, and highly-non-equilibrium microplasma chemistry.

Ultra‐small CuO nanoparticles with tailored energy‐band diagram synthesized by a hybrid plasma‐liquid process

“…The mechanisms leading to the formation of CuO NPs will be now discussed. The investigation of mechanisms induced at the plasma‐liquid interface represents a new and fast growing field within the plasma community . Despite much recent progress, many aspects that can lead to a description of this non‐equilibrium and complex interface are still under debate.…”

“…Despite much recent progress, many aspects that can lead to a description of this non‐equilibrium and complex interface are still under debate. Nonetheless, hybrid plasma‐liquid systems are producing important contributions to nanomaterial synthesis and surface treatment . In particular, hybrid plasma‐liquid approaches have been used to produce various Cu and Cu‐oxide nanostructures, often leading to mixed phases .…”

“…We demonstrate a stable one‐step plasma‐liquid hybrid process for the synthesis of fully dispersed and non‐agglomerated ultra‐small quantum confined CuO nanoparticles (NPs) from bulk copper electrodes in ethanol. Hybrid plasma‐liquid methods are an emerging class of synthesis techniques that have been attracting great interest due to their simplicity and ability to produce quickly and at low cost a very wide range of materials including metallic, bimetallic, semiconducting, and metal‐oxide colloidal nanoparticles from simple and environmentally friendly precursors . It is believed that highly reactive and transient chemistries produced by plasma‐liquid interactions, coupled with local charging of the synthesized NPs, lead to the generation of previously inaccessible surface chemistries and electrostatic colloidal stabilization.…”

Application of Direct Current Atmospheric Pressure Glow Microdischarge Generated in Contact with a Flowing Liquid Solution for Synthesis of Au-Ag Core-Shell Nanoparticles

“…It was shown that non-equilibrium atmospheric pressure plasmas (APPs) enable the production of pure metallic NPs because of the participation of solvated electrons (e aq − ), reactive oxygen species (ROS), and reactive nitrogen species (RNS) in the reduction process of Au(III) or Ag(I) ions to their metallic forms and nanofluids formation [27,28,29,30,31]. To the best of our knowledge, only two research groups have reported the production of the bimetallic Au-Ag NPs using APPs [32,33] as an alternative to the conventional methods. Shirai and co-workers described the production of CSNPs that consisted of an Au-core and an Ag-shell by electron irradiation of the solution surface using a dual-plasma system based on atmospheric pressure glow discharge (APGD) generated in contact with liquid.…”

“…The disadvantage of this method was a relatively low production rate of Au@AgNPs, caused by performing the reaction in a stationary mode [32]. Yan and co-workers also found that non-equilibrium APPs could be used to generate the Au core-Ag shell nanostructures in a stationary mode system [33]. …”