Nanoporous carbon materials are becoming increasingly popular as a material for the manufacture of a new class of devices and the improvement of existing ones. Today, columnar graphene, which is a monolayer of graphene interconnected by vertically oriented carbon nanotubes, as well as recently synthesized laser-induced porous graphene, are classified as nanoporous carbon materials. Applications for such nanomaterials are supercapacitors, batteries, gas filters and DNA sensors. Despite a wide study of the properties of nanoporous carbon, many questions remain. And the main issue is property management by modifying, controlling topology, filling the pores with atoms of various elements or nanoparticles. First of all, interesting and necessary is the search for ways to control electronic properties.
The scientific team of the Department of Radio Engineering and Electrodynamics, led by Professor Olga Evgenievna Glukhova, together with scientists from the Institute for High Performance Computing (Agency for Science, Technology and Research, Singapore) conducted detailed computer studies of the process of filling potassium atoms with nanopores of planar layered and bulk column graphene, as well as films and 3D -samples of glassy porous carbon. Using high-precision quantum methods and the molecular dynamics method, it was shown that high-energy beams of neutral potassium atoms are able to penetrate dozens of layers into the composite. The critical beam energy corresponding to the atomic velocity of ~ 200 m / s was established. A further increase in energy leads to local destruction of the carbon skeleton. However, a series of numerical experiments showed that the framework of a nanoporous carbon material relaxes after collision with potassium atoms and restores its integrity.
It was also first established that it is possible to control the concentration of potassium in the pores by directing a beam of potassium atoms. A low potassium concentration is achieved with a vertical direction of the beam to the surface of the composite. A significant increase in concentration is observed when the beam is directed to the side surface of the composite. The studies of the team showed that the electronic parameters of the nanoporous carbon material can be effectively controlled by adjusting 1) the concentration of potassium in the nanopores; 2) nanopore sizes.
The obtained results open up a new path for the developers of emission electronics, since the new approach developed by the authors for filling nanopores and the established regularities of the electrical conductivity of potassium-doped nanoporous carbon material make it possible to control and control the work of the electron exit.
The results are published in the highly rated journal of the Royal Chemical Society of Great Britain - Nanoscale (Impact factor: 6.97). The full text of the article is on the website of the journal Nanoscale, 2019, 11, 16414–16427.
The figures illustrate the process and result of filling nanopores with potassium.