Quantum capacitance of iron metal doped boron carbide monolayer-based for supercapacitors electrodes: A DFT study

[Display omitted] •Carbon-based nano-structures as electrode materials for super-capacitors has been on the rise.•The capacitance, electronic, energy and structural characteristics of the FBC3ML were inspected.•Fe-doping changed the FBC3ML from a semi-conductor into a metal. In the last decades, many research studies have been carried out into carbon-based nanostructures as electrode materials for supercapacitors. The current research study introduced a new carbon-based electrode by using a two-dimensional (2D) Fe-doped boron carbide monolayer (FBC3ML). The capacitance, electronic, energy and structural properties of the FBC3ML were investigated by performing first-principles density functional theory (DFT) calculations. The results demonstrated that the formation energies of FBC3ML are low, which indicate its easy experimental synthesis. Interestingly, due to the shift in the Fermi level to the conduction/valence bands, Fe-doping changed the FBC3ML from a semi-conductor into a metal. By calculating the quantum capacitance of the FBC3ML, it was found that its capacitance reached 150.09 μF/cm2, which substantially outperformed other 2D carbon-based electrodes. The FBC3ML with tunable electronic properties and high specific surface area can be regarded as a promising candidate for energy storage devices and supercapacitors.