Smart nanomaterials with designed properties based on nanoparticles have the potential to revolutionize applications in magnetics, catalysis, and optoelectronics. But implementing nanoparticles’ potential for such applications requires realizing and understanding nanoparticles with controllable size, morphology, crystal structure and chemical composition on a large scale, at low costs and in a safe and environmentally friendly way. So far, this has not been done to a great extent because few methods exist that can enable large-scale production of materials with high enough control of the designed particle properties mentioned, thus hampering the exploration of a wide range of nanoparticle-based materials.
Very recently aerosol generation by the spark discharge method has been identified, within the large EU-program Buonapart-e, as the method that can fulfill all of the above-declared requirement, but so far mainly the large-scale production capabilities have been demonstrated but work remains when it comes to the designed nanoparticles.
Nanoparticle generation by spark discharge where the formation of a plasma channel between two conducting electrodes leads to a spark discharge that evaporates material is a fairly simple method. To create a spark discharge between the electrodes a self-pulsed circuit is used, consisting of a capacitor bank driven by a high voltage DC power supply connected in parallel to the electrode gap. Several parameters can be adjusted to affect and control the particle production including the capacitance, the discharge frequency (by the output current), the electrode distance, the electrode material, the carrier gas flow rate, the type of carrier gas and the geometry of the spark discharge generator.
Here, we report on how the generation parameters, as well as the post-treatment of the produced particles, can be used to control their crystal structure, size, morphology and chemical composition. In addition, some examples of applications where the as-produced particles with designed properties have been used will be presented.