RETRACTED: Quantum capacitances of transition metal-oxides (CoO, CuO, NiO, and ZnO) doped graphene oxide nanosheet: Insight from DFT computation
Idongesit J. Mbonu, Ernest E. Ekereke, Terkumbur E. Gber, Cookey Iyen, Ismail Hossain, Godwin O. Egah, Ernest C. Agwamba, Adedapo S. Adeyinka, Hitler Louis
Abstract
Density functional theory (DFT) computation has been utilized to explore the effects of the transition metal oxides: CoO, CuO, NiO, and ZnO doping on the electronic properties, structural, and quantum capacitances of graphene oxide nanosheet. From the magnetic moment analysis CoO@GO was observed to have higher magnetic moment of 11.688 μB compared to the studied the transition metal oxide doped systems. Investigation into the electronic properties revealed that NiO@GO attained higher energy gap with value of 0.144 eV. It was observed that that the GO O/C affects the bandgaps of the modelled systems. Perturbation theory analysis of fock matrix showed that CoO@GO and CuO@GO possessed higher second order stabilization energy with values 238.56 kcal/mol and 208.94 kcal/mol respectively. From the quantum capacitance studies, it was observed that the value of CQ for graphene oxide (GO) increased slightly from 72.276µF/cm2 to ZnO@GO (121.550 µF/cm2) > NiO@GO (93.870 µF/cm2) > CoO@GO (90.52 µF/cm2) > CuO@GO (89.375 µF/cm2). The results obtained herein can provide an effective and simple new idea for the design of graphene-based supercapacitors that possess high energy density.