Synthesis of Self-Assembled rGO-Co3O4 Nanoparticles in Nanorods Structure for Supercapacitor Application

Abstract

A simple hydrothermal process was used to design self-assembled Co3O4 nanoparticles in nanorod structure in the presence of graphene oxide as a template. The as-prepared Co3O4 sample in a loose powder form was calcined at 450 °C to get the well-crystalline phase of the same compound. The obtained Co3O4 powder sample was characterized by using the powder XRD and SEM. The XRD pattern shows totally nine distinct reflection peaks of (111), (220), (311), (222), (400), (422), (511), (440), and (533) planes. The most intense peaks were chosen to evaluate the structural parameters. The lattice parameters (a), volume (V), and density (ρ) of the samples are 8.09 A, 529.47 A3, 6.06 g/cc, which are comparable to the value of lattice parameter (a = 8.056 A), volume (V = 528.30 A3), and density (ρ = 6.055 gm/cc) for bulk Co3O4. The average size of the Co3O4 nanoparticles is 14 nm which is smaller than the SEM size of 50 nm corresponding to the agglomeration of tiny particles. Further, the formation of Co3O4 nanoparticles were also confirmed by obtaining the band at 569, 1334,1337, 1566, and 3397 cm−1 in FTIR spectrum. Totally five characteristics peaks from Co3O4 at 182.57, 456.49, 505.84, 605.80, and 618.02 cm−1 and peaks from GO-Co3O4 at 182.57, 483.44, 505.84, 605.80, and 618.02 cm−1 corresponding to F2g, Eg, F2g, F2g, and Ag modes of the crystalline Co3O4, respectively, in the Raman spectra. In the case of GO-Co3O4 composite, low-intensity peaks of D and G bands are observed. The specific capacitance in rGO-Co3O4 nanocomposite is about 65.15 Fg−1.