Electrode material for high performance symmetric supercapacitors based on superparamagnetic Fe3O4 nanoparticles modified with cetyltrimetylammonium bromide

A facile preparation method is reported to develop a supercapacitance material with high specific capacitance and stability. Fe3O4 superparamagnetic material was synthesised via CTAB assisted co-precipitation method to modify the morphology. Presence of CTAB has resulted in excellent output in terms of high specific capacitance of 1192 F/g at a current density of 1 A/g. 93% of charge storage capacity was retained by the working electrode after 4000 charge-discharge cycles with the optimum concentration of CTAB. The TEM micrograph showed a quasi-spherical morphology for the bare Fe3O4 and the same was modified to semi-cuboidal shape after CTAB modification. The change in crystal lattice was confirmed through SAED in parallel to the WAXRD analysis. The phase purity was deciphered using XPS and surface roughness of the electrode was studied using AFM. Increased saturation magnetisation value for CTAB modified Fe3O4 was also in line with the improved charge storage capacity. [Display omitted] •Superparamagnetic Fe3O4 nanoparticles successfully capped with CTAB.•Fe3O4/CTAB used for supercapacitor electrode material.•The highest ever reported Specific Capacitance of 1192 F/g achieved for CTAB modified Fe3O4.•The material recorded excellent cyclic stability.•93% performance was retained after 4000 charge-discharge cycles.