Interaction of K2CrO4 Oxide Nanoparticles with Carbon Nanostructures

Interactions of the surfaces of potassium chromate crystal nanoparticles with carbon nanotubes and graphene are computationally studied by the electronic structure calculations within the molecular cluster approach. Three types of carbon nanostructures were considered in calculations: single-walled (~ 0.7 nm in diameter) and multiwalled carbon nanotubes (~ 5 nm in diameter), fragments of graphene sheet. Potassium chromate crystal fragments of linear sizes ranging from ~0.5 to ~2 nm (chromate anion and potassium chromate clusters consisting of 1 – 32 formula units of the crystal) were modeled in calculations. The results of the calculations revealed the mechanism of bonding between oxide crystal fragments and carbon nanostructures. It was found that the graphene sheet most effectively interacts with such a surface of the potassium chromate crystal that contains the most possible number of potassium cations. It was shown that the interaction of single-layer graphene sheets with fragments of potassium chromate having linear dimensions of several nanometers leads to significant distortion (twisting) of the graphene sheet. Conclusions regarding the possibility of efficient adsorption of crystal nanoparticles by the surfaces of real carbon nanostructures were made.