Home – Home – Jornals – Chemistry for Sustainable Development 2022 number 5

The TUBALL material consisting of single-walled carbon nanotubes (SWCNTs) is characterized. The features of the formation of nanostructured composites through the reduction of HAuCl₄ solutions by the matrix (carbon) on the outer surface of coalesced nanotubes are considered, their morphology and the features of occurrence of thermally stimulated processes are studied, as well as their electrochemical properties in supercapacitor (SC) model cells. According to transmission electron microscopic data, the incorporated gold nanoparticles are probably shaped as flattened ellipsoids with particle size of 6-30 nm (30-40 nm according to X-ray diffraction data) and are located on the surface of “ropes”, which are close-packed ensembles of parallel SWCNTs. According to the results of sorbometry, the internal channels of SWCNT (1-2 nm) and extended pores between them are accessible to sorbed nitrogen, but inaccessible to the precursor solution. The sizes of coherent scattering regions, estimated from the broadening of X-ray diffraction reflections, turned out to be larger than particle sizes determined by means of TEM, which is due to their anisometric nature. The study of thermally stimulated processes in composites shows that gold deposition on the SWCNT surface leads to an increase in the stability of C-matrix against oxidation. Investigation of Au/SWCNT nanocomposites as electrode materials for supercapacitors shows that decorating the surface of SWCNT “ropes” with gold causes a significant decrease in the active component of the impedance and an increase in the electric capacitance of the SC cells in the region of high potential scanning rates, as a consequence of an increase in charge density at TUBALL/Au/electrolyte interfaces during polarization, and a decrease in electric resistance. The greatest effect (an increase in capacity by a factor of 3.0-3.5) was observed for the nanocomposite electrode 2 wt. % Au/SWCNT.