Supercapacitor properties of Cu₂O/Cu(OH)₂ composite thin films deposited on nickel foam using pulse reverse potential electrodeposition

In the quest for low-cost and eco-friendly energy storage materials, copper-based oxide/hydroxides emerge as promising candidates. In this study, Cu₂O/Cu(OH)₂ composite thin films were prepared on nickel foam using the pulse reverse potential (PRP) electrodeposition technique. In PRP electrodeposition, repeated cathodic/anodic deposition cycles were employed to produce the composite thin films. Here, deposition time emerged as a critical factor in controlling the composition and morphology of the final product. By adjusting the deposition time Cu₂O/Cu(OH)₂ composite thin films were prepared successfully with desired morphologies and optimum Cu₂O/Cu(OH)₂ content. The morphology and composition of the final product were analysed using SEM, EDX, XPS and FTIR. An effort has been made to correlate the electrochemical properties of the composite thin films based on their composition and morphology obtained at varying deposition times. The Cu₂O/Cu(OH)₂ composite thin film, containing an optimal content of Cu₂O and Cu(OH)_2, exhibits an interconnected flakes-like morphology and achieves the highest specific capacitance of 1709 F/g at a current density of 1 A/g. It also demonstrates enhanced cycling stability by maintaining over 80% of its initial capacitance after 2000 cycles.