Abstract

Graphene oxide (GO) was synthesized by the modified hummers method and bismuth titanate (BTO) was prepared in two different processes: the pechini method and the sol-gel method. The x-ray diffraction (XRD) analysis of GO indicates a perfect preparation of GO nanocomposites where the dominant crystal plane (0 0 1) was observed at 11.25⁰.  The (XRD) analysis of BTO nanocomposites indicates the orthorhombic structured perovskite phase and the most dominant peak was observed at 30.15⁰ for the crystal plane (117). But the BTO nanocomposites prepared in pechini method have some multiphase of sillenite phase of BTO. After comparing all of the properties of the nanocomposites prepared in these two processes, we choose the composites prepared by the sol-gel process for further work. Then cobalt has been doped in BTO nanocomposites in the ratio of 10%, 30%, and 50% by the sol-gel process. The structural distortion of cobalt-doped BTO materials (CBTO) was due to the difference between the radii of Co dopants and Ti hosts. After comparing their properties, we choose 10% CBTO for GO reinforcement. GO-reinforced nanocomposites were prepared by the Separable addition process in the hydrothermal route. Crystal size, dislocated density, micro-strain, lattice parameters, miller indices, and volume of all composites were measured from XRD data. Here the crystal size linearly decreases with cobalt doping and increases after GO reinforcement. The maximum crystal size we got for 9% GO CBTO is 46.97 nm. From all CBTO nanocomposite XRD peaks, we can say there is no extra peak for cobalt ions that represent perfect doping in BTO composites and the XRD peaks of GO-CBTO composites indicate a good bonding between GO and CBTO. With the FTIR analysis, we identify all the vibrational bonding in the nanocomposites. The FTIR study revealed the presence of all the functional groups present in the nanocomposites, for which the composite may be able to remove dyes in industrial arrangements. The XRD and FTIR analysis of the composites confirmed the incorporation of CBTO nanocomposites into the GO matrices without altering its orthorhombic structure and perovskite phase. The optical properties were studied by UV-vis DRS which illustrates the reflectance and bandgap of all nanocomposites. This showed a decrease in bandgap after doping and GO reinforcement from the bandgap of BTO nanocomposites, which is 3.3 eV. The magnetic properties of all composites were studied by the PPMS system. The magnetic properties of GO-CBTO composites showed soft magnetic nature with the increases in GO percentage, so it is able to filter the heavy metals from the aqueous solution.