Structural, optical and electrical properties of Ni-doped Co3O4 prepared via Sol-Gel technique

Abstract

In this article, Nickel doped Cobalt oxide thin films and powders have been prepared on glass substrates using sol gel based dip coating process in order to investigate their optical, structural and electrical properties. The Ni concentration was changed from 0 to 9 wt(%).The synthesized samples were characterised by Ultraviolete visible analysis, X-ray diffraction, Fourier transform infrared spectroscopy and Complex impedance spectroscopy to depict the optical, structural, vibrational and electrical properties. Our structural results show that the obtained samples were composed of (Co 3 O 4) polycrystalline with spinel-type preferentially oriented in the (311) plane. Our optical results show that the films have high transparency over the visible region (85% for Co 3 O 4 and ~ 60-75% for all doped samples). The optical band gaps were found to be (E g1 = 1.50 eV, E g2 = 2.20 eV) and (E g1 = 1.42 eV, E g2 = 2.07 eV) for the case of (pure Co 3 O 4 and 9% Ni-doped Co 3 O 4) respectively. The complementary phase information is provided by FT-IR spectroscopy. FT-IR spectra confirms the presence of Co 2+-O and Co 3+-O vibrations in the spinel lattice. The Nyquist plots suggests that the equivalent circuit of our films is an parallel circuit R p C p. It was found that the resistance Rp decreases whereas the capacity Cp increases with increasing doping levels.

Synthesis and evaluation of nickel doped Co3O4 produced through hydrothermal technique

“…These results agree with the works of Singhal et al [21,31] where the peaks represent a good crystallinity and they obtained a crystallite size of 36-42nm. These results can also be associated with the research by Lakehal et al [10], who prepared films and fine powders of nickel-doped cobalt oxide on glass substrates. They used an immersion coating process based on sol gel with a concentration of Ni in the range from 0 to 9% by weight (%).…”

“…The highest bandwidth energy changed from 2.74eV for Co3O4 to 1.54eV for Co3O4 at 300°C. This behavior can be attributed to the lattice distortions caused by the temperature change, as well as to the introduction of nickel ions in the Co3O4 matrix and the formation of impurity energy levels (acceptor level) [10]. The morphology and structures of the materials are closely related to their optical properties, which are more evident in nanomaterials [36].…”

“…The synthesis of cobalt oxide compounds with adjustable physicochemical properties has become a research point, where doping with transition metals improves properties such as electrical behavior as well as optical absorption [10]. Specifically, doping of Co3O4 with nickel has shown significant changes in the behavior of the material.…”

Recent Advance in Co3O4 and Co3O4-Containing Electrode Materials for High-Performance Supercapacitors

“…Co 3 O 4 nanoparticles with no secondary phase were synthesized via the sol-gel method [46]. The Co 3 O 4 nanoparticles delivered a Cs of 120 F•g −1 at 1 A•g −1 in a voltage window of 0 to 0.6 V. In addition, Lakehal et al [47] prepared Co 3 O 4 electrode materials by adopting the sol-gel-based dip-coating process on a glass substrate. Meanwhile, the effects of Ni-solution concentrations on the properties of Co 3 O 4 samples were studied.…”

Development of oxygen vacancies and surface defects in Mn-doped ZnO nanoflowers for enhancing visible light photocatalytic activity

“…We have selected the hydrothermal technique to synthesis Mn-doped ZnO nanoflowers because it is a cost-effective and most appropriate technique for getting fine morphology of one-dimensional single crystalline material. To study the effect of photocatalytic activity of pure and Mn-doped ZnO nanoflowers under solar light may change optical, electrical and morphological properties of ZnO because their atomic radii are almost equal and properties are influenced by the quantum confinement of electronic states of bulk ZnO are due to doping of transition metals [23]. Here, we report our work on the development of oxygen vacancies and surface defects into pure and Mn-doped ZnO nanoflowers in an effective approach.…”