The impact of zinc ions on electrode material for energy storage in solvothermal-synthesised graphene-zinc oxide nanocomposites

The study examines the impact of zinc ions on energy storage in solvothermal-synthesised graphene-zinc oxide nanocomposites. In recent years, there has been extensive research focus on graphene and metal oxides, particularly in heterostructures and composites. These materials have a broad range of applications, like energy storage. Faradaic processes were shown by the observation of redox peaks in the CV analysis of a three-electrode system. The estimated specific capacitances of graphene at scan rates of (1, 50, and 100) mVS−1 were (1250, 562.5, and 390.6) Fg−1. The G-ZnO (2 w%) and G-ZnO (3 w%) gave the specific capacitance of (1354, 750, and 520) Fg−1 and (1422, 818, and 568) Fg−1 at the same scan rates of 1, 50, and 100 mV/s. Applying a potential to the material reveals its pseudo-capacitive properties. The XRD results for G-ZnO (2 w%) and G-ZnO (3 w%) show diffraction peaks at 2θ = 20.56°, 32.95°, 40.69°, 47.41°, 59.02°, and 69.04°, which correspond to the diffraction planes 011, 100, 101, 102, 110, and 200, respectively.