Graphene Oxide/Nickel Chromite Nanocomposite: Optimized Synthesis, Structural and Optical Properties

Abstract

Graphene oxide based nickel chromite nanocomposite (GONC) was synthesized via a cost effective chemical co-precipitation method for energy storage applications. As-synthesized nanomaterial was characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, an elemental composition diagnostic via energy dispersive spectrscopy, optical properties via raman spectroscopy, bandgap transition measurements via photoluminescence spectroscopy, and electrochemical impedance spectroscopy and cyclic voltammetry to measure electron-transfer resistance and electrochemical active surface area. A grain size value of about 1.55 nm with nickel particles aggregation over graphene oxide surface results in nickel non-homogenous distribution with spherical grains. This leads to structural defects resulting in a downward shift at about 1430 cm −1 as observed via raman spectra. Also, a electrochemical active surface area of 0.08 cm 2 comparable to GCE surface area leads to better conductivity with a decrease in Rct upto 5.4 KΩ. It is therefore considered to be an ideal material with optimized parameters to be synthesized as tested for energy storage applications.

Investigation of copper/cobaltMOFsnanocomposite as an electrode material in supercapacitors

“…Figure 9 shows Nyquist plot for Cu‐MOF, Co‐MOF and Co/Cu MOF nanocomposite utilizing an EIS fitted model to investigate the electron‐transfer mechanism. The electron shift rate constant k app has been determined for the veteran electrode using k app = RT/F 2 .R ct .C where R ct calculated values are 1.72 Ω,1.52 Ω and 1.3 Ω with k app values 1.55 × 10 −7 cm 2 s −1 , 1.75 × 10 −7 cm 2 s −1 and 2.01 × 10 −7 cm 2 s −1 respectively 67,68 . Obvious from the Nyquist plot suitable, for a semicircle high power related to charge shift resistance R ct 69 .…”

“…The electron shift rate constant k app has been determined for the veteran electrode using k app = RT/F 2 .R ct .C where R ct calculated values are 1.72 Ω,1.52 Ω and 1.3 Ω with k app values 1.55 Â 10 À7 cm 2 s À1 , 1.75 Â 10 À7 cm 2 s À1 and 2.01 Â 10 À7 cm 2 s À1 respectively. 67,68 Obvious from the Nyquist plot suitable, for a semicircle high power related to charge shift resistance R ct . 69 Ions disperse always shown as a direct line in the low frequency array representing hydroxyl ions diffusion within electrode material resulting in Warburg Impedance (W).…”

A novel construct of an electrochemical acetylcholinesterase biosensor for the investigation of malathion sensitivity to three different insect species using a NiCr2O4/g-C3N4 composite integrated pencil graphite electrode

“…The potential of g-C 3 N 4 to develop novel nanocomposites with exceptional electrocatalytic and physiochemical properties has been reported by various researchers. 39 The integration of NiCr 2 O 4 to g-C 3 N 4 would cause a unique surface contact between g-C 3 N 4 and chromite, resulting in a large electrochemical surface area and accessibility of active sites that would lead to increased electrocatalytic efficiency of the modified electrodes. 40 In addition, considering the role of nickel in specific enzyme immobilization, 41 the composite was expected to possess effective biocatalyst immobilization ability.…”

Morphological and optical investigation of 2D material-based ternary nanocomposite: Bi2O3/MgO/GO synthesized by a co-precipitation technique

“…The following steps for the co-precipitation method 48–52 were used in the preparation of Bi 2 O 3 /MgO/GO ternary nanocomposite:…”

“…Preparation of Bi 2 O 3 /MgO/GO ternary nanocomposite by the co-precipitation method. The following steps for the co-precipitation method [48][49][50][51][52] were used in the preparation of Bi 2 O 3 /MgO/GO ternary nanocomposite: 0.01 g of GO prepared by Hummers' method was dissolved in 100 mL of DI water in a beaker, which was sonicated for 60 min.…”