Periodic Reporting for period 3 - PEGASUS (Plasma Enabled and Graphene Allowed Synthesis of Unique nano Structures)
Période du rapport: 2020-05-01 au 2022-05-31
To this end, the project's ambitious goal is to translate the unique properties of plasma into exceptional material characteristics and create new forms of matter by using multiple specific plasma mechanisms to control energy and matter transfer processes at nanoscale. The primary objective of PEGASUS is the design and construction of a proof-of-concept operating machine for the gram-scale production of nitrogen-doped graphene (N-graphene) and graphene/N-graphene hybrids containing metal oxides via plasma-based single-step method under atmospheric pressure conditions. Considering the extension of N-graphene properties into the third dimension, the development of graphene-based 3D architectures, such as unique vertical N-graphene arrays grown on metal substrates and their hybrids, is also being pursued.
Moreover, a novel method for a single-step, microwave plasma driven controllable assembly of nanocomposites comprising N-graphene sheets decorated with metal oxide nanoparticles at atmospheric pressure that circumvent drawbacks associated with conventional methods was developed. The plasma-based method enables reduction of micron sized metal oxides particles into nanoparticles as well as formation of new phases of metal oxides.
Furthermore, vertically aligned N-graphene structures were fabricated using low-pressure radio frequency inductively coupled cold nitrogen plasma treatment, and a high doping level (~8-12 at %N) was attained. It is also identified that the bonding configurations of the nitrogen groups can be adjusted by varying plasma parameters. Based on the experimental evidences, a nitrogen incorporation mechanism in graphene is established. A fast and facile technique for decorating vertical graphene and vertical carbon structures with metal nanoparticles using plasma sputtering was also elaborated. Exploiting capacitively coupled RF plasma where temperatures go as low as 480°C fast growth (minutes) of vertical graphenes/N-graphenes was achieved for a large variety of substrates. Using a hybrid microwave-DC plasma reactor vertically oriented carbon nanostructures were successfully grown on Ni-foam in a very short time (~ 8 min) at atmospheric pressure conditions as well.
Taking advantage of the exceptional electrical conductivity and extensive electrochemically active surface area of the graphene produced within the project, two supercapacitor demonstrators were developed. Aimed at IoT applications, a graphene-based supercapacitor as well as a smoothing AC-DC converter supercapacitor with the potential to replace tantalum electrolytic capacitors have been developed.
In addition to the above energy storage applications, some of the graphene-based vertical nanostructures produced during the PEGASUS period have been shown to have excellent energy storage properties for battery systems, suggesting the extension of the project to various research areas related to energy.
The PEGASUS project opens up a new way for custom-made 2D carbon materials and their 3D architectures. The impact is definitely a breakthrough, as it combines Europe's most ambitious goals in nanomaterials as key technologies: destructive properties through cheap green roads that allow existing materials to be replaced by new, cost-effective and more efficient one. The development in this field of plasma technologies is expected to have a great influence in the applications of energy storage and conversion devices, conductive inks, nanocomposites, membranes, sensors, metamaterials, etc.
Strategic achievements:
• Formation of an ever-growing user community of scientists to explore the new physics and application opportunities related with graphene/N-graphene and derivatives.