Influence of Co doping on phase, structure and electrochemical properties of hydrothermally obtained CoxZn1−xFe2O4 (x = 0.0–0.4) nanoparticles

Abstract

In this work, CoxZn1−xFe2O4 (x = 0.0–0.4) nanoparticles (NPs) were successfully synthesized by a hydrothermal method at 200 °C for 12 h. X-ray diffraction revealed a pure cubic spinel phase of all samples with space group Fd-3m. Fourier transform infrared spectrometry disclosed the vibrational modes of metal oxides in the spinel structure. Scanning electron microscopy and transmission electron microscopy disclosed a uniform distribution of cuboidal shape NPs with a decreased average NPs size from 22.72 ± 0.62 to 20.85 ± 0.47 nm as the Co content increased. X-ray absorption near edge spectroscopy results confirmed the presence of Zn2+, Co2+ and Fe2+/Fe3+ in Co-doped samples. The pore volume, pore size and specific surface area were determined using N2 gas adsorption/desorption isotherms by the Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) techniques. Electrochemical properties of supercapacitors, having active CoxZn1−xFe2O4 (x = 0.0–0.4) NPs as working electrodes, indicated pseudo-capacitor performance related to the Faradaic redox reaction. Interestingly, the highest specific capacitance (Csc), 855.33 F/g at 1 A/g, with a capacity retention of 90.41% after 1000 GCD cycle testing was achieved in the Co0.3Zn0.7Fe2O4 electrode.

Nickel-copper-cobalt mixed oxide electrode material for high performance asymmetric supercapacitor

“…The significance of energy storage is escalating as every number of renewable sources of electricity is expanding dramatically 1 – 3 . Technologies with high power density, energy density, along with adaptive energy storage be necessitated considering the rapid emergence of electric-powered automobiles and portable consumer electronics.…”

“…Hu et al enlarged flower-like Ni-Zn-Co oxide NWs among specified capacity (776 F g −1 ) also real capacity of 1.16 F cm −2 (2 A g −1 ), long cycle stability of 88.9% with capacity retaining of 73.8% (32 A g −1 ) with every collected aqueous symmetric supercapacitor having an energy and density of power is 44.5 Wh kg −1 at 880 W kg −1 1 . Putjuso et al combined Co x Zn 1−x Fe 2 O 4 nanoparticles by hydrothermal method at 200 °C for 12 h. with highest particular capacities, 855.33 F g −1 (1 A g −1 ), by a high-quality rate ability retaining of 90.41% after 1000 sequences 3 . Kim et al made-up electrodes with combined (La 0.8 Sr 0.2 Mn 0.5 Co 0.5 O 3−δ ) materials carrying redox reaction capacity through graphene nanosheets with great capacitance and exceptional withholding of 95% after 5000 series 4 .…”