An original tuneable plasma process for the synthesis of tailored nanoparticles

The use of efficient, durable and low-impact processes for the environment is highly desirable to synthesize nanomaterials for various applications. A new approach 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 in order to generate e.g. new catalytic systems. 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 is 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 nanoparticles synthesis can be monitored in situ using optical emission spectroscopy of the plasma discharge. Applications in photocatalysis, magnetic materials, or catalysts for fuel cells are demonstrated.