Borophene, a crystalline allotrope of monolayer boron, with a combination of triangular lattice and hexagonal holes, has stimulated wide interest in 2-dimensional materials and their applications.

Carbon quantum dots (CQDs) are discrete, quasi-spherical carbon nanoparticles with sizes below 10 nm.

A ternary nanocomposite that consists of MnO₂ nanorods and reduced graphene oxide sheets supported on poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT:PSS) polymer has been developed for supercapacitor applications. X-ray diffraction, field emission scanning electron microscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, the Brunauer–Emmett–Teller method and X-ray photoelectron spectroscopic analysis confirmed the formation of a ternary nanocomposite of PEDOT:PSS/MnO₂ nanorods/rGO. Electrochemical investigation of these materials in acetonitrile containing lithium per chlorate demonstrated an enhanced specific capacitance of 633 F g⁻¹ at a current density of 0.5 A g⁻¹ and 100% stability up to 5000 charging–discharging cycles at 1 A g⁻¹. The enhanced capacitance and working stability of the PEDOT:PSS/MnO₂ nanorods/rGO nanocomposite along with the simplicity in making the active materials make this system a promising candidate for the commercial development of supercapacitors.