Iron Nanoparticles Wrapped with an N-Doped Carbon Material Produced by Using a Zinc Hydroxide Ferrocyanide Nanohybrid for Use in Commercial-like Supercapacitors.

Abstract

According to the technology of carbon-based supercapacitors, modifying the structure of carbon as an active electrode material leads to an increase in capacitance. A modification involves introducing heteroatoms such as nitrogen into the carbon structure and composing it with metals such as iron. In this research, an anionic source called ferrocyanide was used to produce N-doped carbon consisting of iron nanoparticles. In fact, ferrocyanide was located as a guest between the layers of a host material, which is zinc hydroxide in the α phase. This new nanohybrid material was then heat-treated under Ar, and the heated product after acid washing was iron nanoparticles wrapped with N-doped carbon materials. This material was used as an active material in the production of symmetric supercapacitors with different organic (TEABF4 in acetonitrile) and aqueous (sodium sulfate) electrolytes as well as a new electrolyte (KCN in methanol). Accordingly, the supercapacitor made by the N/Fe-carbon active material and the organic electrolyte showed a capacitance value of 21 F/g at a current density of 0.1 A/g. This value is comparable to and even higher than the values observed in commercial supercapacitors.