Preparation of an O/N/P/S co-doped hierarchical porous carbon material derived from snake skin for supercapacitors

An O/N/P/S co-doped carbon material with hierarchical porous structure for supercapacitors is prepared from snake skin by a simple calcination method, which exploits its own scaffold silica (SiO2) as the self-sacrifice template combining with the activated agent potassium hydroxide (KOH). The KOH acts not only as activator to create micropores, but also as etching agent to remove the nonconductive SiO2 in situ, leading to better conductivity, as well as forming mesopores and macropores. The influences of calcination temperature and SiO2 etching on the electrochemical performances are discussed. Under the synergistic effects of the hierarchical pores in its structure and the existing of multiple hetero atoms, as well as the removal of SiO2, the obtained carbon material (C-KOH) displays outstanding specific capacitance (717.6 F g− 1 at 1 A g− 1) and excellent stability (120% capacitance retention rate after 40,000 cycles).