Functionalize and supercapacitor performance of magnetic oxide nanoparticles

[Display omitted] •Electrochemical performance of synthesized electrodes Fe3O4, Fe3O4@SiO2, Fe3O4@SiO2-2-(6-(3-amino-4-hydroxyphenyl)diazenyl)-1λ4-thiopyran-3-carboxylic, CoFe2O4@SiO2-2-(6-(3-amino-4-hydroxyphenyl)diazenyl)-1 λ 4-thiopyran-3-carboxylic.•Magnetic Fe3O4@SiO2, CoFe2O4@SiO2 core–shell nanocomposite. Photosynthesis Magnetic with core–shell structure, Fe3O4@SiO2-2-(6-((3-amino-4-hydroxyphenyl)diazenyl)-1 λ 4-thiopyran-3-carboxylic acid and CoFe2O4@SiO2-2-(6-((3-amino-4-hydroxyphenyl)diazenyl)-1 λ 4-thiopyran-3-carboxylic acid have been prepared by a facile Stober method. These materials exhibited excellent supercapacitor performance, which was both efficient and highly stable. The nanocomposites were characterized by XRD, XPS, FESEM-EDX-mapping and TEM. The XRD results exhibit synthesis of Fe3O4 phase and CoFe2O4@SiO2-2-(2-benzothiazolyl azo)-4-methoxyaniline. The FESEM images show nanoparticles that have been agglomerated into spherical shapes while the TEM results reveal that the nanoparticles have been functionalized with magnetic properties using SiO2-2-(1-(4-((3-amino-4-hydroxyphenyl)diazenyl)phenyl)ethan-1-one. The two electrodes illustrated high specific capacitance of 679 and 630F.g−1 and excellent stability up to 1000 cycles charge–discharge cycles. The results indicated that the capacitance value of CoFe2O4@SiO2-2-(6-((3-amino-4-hydroxyphenyl)diazenyl)-1 λ 4-thiopyran-3-carboxylic acid is higher than Fe3O4@SiO2-2-(6-((3-amino-4-hydroxyphenyl)diazenyl)-1 λ 4-thiopyran-3-carboxylic acid, revealing the extraordinary performance of CoFe2O4 electrode. The electrochemical activity of CoFe2O4 electrode is attributed to the synergistic effect of oxidation–reduction coupling between copper and ferric ions.