Phosphorous and sulfur doped asphaltene derived activated carbon for supercapacitor application

• The asphaltene can used a supercapacitor after doping some heteroatoms. • Progresses on N, S & P atoms doped on activated carbon–asphaltene composite. • Impact of N&P doping species on activated carbon–asphaltene composite. • Current challenges on activated carbon–asphaltene composite in supercapacitors. • Remarkable specific capacitance and cycle stability were demonstrated. It is important to develop alternative methods for obtaining hierarchical porous and heteroatoms-doped carbon for the fabrication of a high-performance supercapacitor that is both effective and inexpensive. In this research, asphaltene rich-sulfur derived activated carbon (As-AC) is prepared by one-step pyrolysis of asphaltene. But, further phosphorous doping Asphaltene derived activated carbon (P-As-AC) was fabricated with facile pyrolysis of As-AC at 300 °C in the presence of (NH 4 ) 2 HPO 4 . The synthesized materials were characterized by XRD, BET, EDAX, XPS, TEM, FTIR, Raman and Zeta potential analysis. XRD diagram show two broad diffraction peaks for As-AC and P-As-AC samples were displayed at 2Ө values of around 24° and 42°, respectively. The total specific surface area (SSA) of As-AC was 425.7 m 2 g −1 while that of P-As-AC that doped with phosphorus decreased sharply to 18.468 m 2 g −1 . The total pore volume decreased from 0.5 cm 3 g −1 for As-AC to 0.023 cm 3 g −1 for P-As-AC and the pore size decrease from 3.3 nm for As-AC to 2.3 nm for P-As-AC. The supercapacitive activity of As-AC and P-As-AC electrodes was studied by cyclic voltammetry (CV), Galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS). The mechanism of energy storage and charge storage was discussed.