Abstract:
Doping is an alternative strategy for the alteration of as-prepared nanomaterial’s to
enhance their optical, structural, and electrical and electrochemical properties of
electrode materials. In this study, Co3O4
, Ni and Cu -doped Co3O4
Nps at different
dopant level (0.01-0.05 M) were successfully synthesized via cost effective and facile
Co-precipitation method. The synthesized samples structural, functional, optical,
morphological, thermal, and its surface area properties were examined by XRD,
FTIR, UV-vis, SEM, TGA/DTA, and BET. The XRD analysis results show that
prepared nanoparticles consists of Co3O4
crystalline with preferential orientation of
(311) plane for all doping, confirmed cubic spinel structure of Co3O4
. It was also
noted from XRD results, the crystallite size of pure Co3O4
, Ni and Cu doped Co3O4
were in the range of 35.74-34.70 nm. The FTIR-spectroscopy was used to determine
the presence of functional groups in prepared sample (M-O) bonds, M =Ni, Cu, or
Co)). From optical property analysis, the direct allowed band gap energies are
calculated from Taucs plot. The optical band gaps were found to be 3.8 eV for pure
Co3O4
2.85 eV for 5 % Ni doped Co3O4
, and 3.66 eV for 5 % Cu doped- Co3O4
Nps
respectively are observed from UV-vis. The SEM image revealed the formation of
agglomerated rock-type structures in the Co3O4
, Ni and Cu doped-Co3O4
Nps at high
magnification. TGA/DTA analysis showed that Ni, and Cu-doping in Co3O4
leads to
improved thermal decomposition properties. BET analysis showed the doping of Ni
and Cu improved the surface area properties and further ionic diffusion rates of
prepared samples. Cyclic voltammetry (CV) technique was used for electrochemical
analysis of Ni and Cu doped Co3O4
nanoparticles. The higher specific capacitance of
449 F/g and 426 F/g at scan rate of 20 mV/s in 1 M KOH solution for 0.05 M Ni and
0.05 M cu doped Co3O4
was observed.
Key words: Co3O4
Nanoparticles, doping, Co-precipitation method,
Supercapacitors.