An original tuneable plasma process for the synthesis of tailored nanoparticles

Abstract

A dry process is presented to synthesize nanoparticles on different powder substrates. The process is based on the plasma degradation of solid organometallic precursors mixed with the powder substrate to generate various nanoparticles of 2-15 nm. Compared to conventional wet chemistry, plasma processing offers the advantage of reducing the environmental impact of the synthesis by reducing the energy consumption and relying on a solvent-free and waste-free scalable process. The novelty and high versatility of the process are demonstrated in this work. Choosing the right discharge parameters (pressure, reactive gas, plasma power…), amorphous or crystalline monometallic, bimetallic, oxide, or nitride nanoparticles can be produced, onto inorganic (such as TiO2) or carbon-based substrates like graphene, carbon xerogel, or carbon nanotubes. Results have been obtained for various nanoparticles, including transition (Mn, Fe, Ni), post-transition (Zn, Al), and noble metals (Cu, Pt, Pd, Rh). Moreover, the organometallic precursor(s) decomposition and the subsequent nanoparticle synthesis can be monitored in situ using optical emission spectroscopy of the plasma discharge.