Exploring the dual functionality of copper oxide for enhanced supercapacitor performance and photocatalysis application

In this study, CuO thin films were deposited onto stainless steel substrates using the SILAR (Successive Ionic Layer Adsorption and Reaction) technique. The samples underwent annealing at various temperatures: room temperature (300 K, 500 K, 700 K, and 900 K). We investigated the impact of annealing temperature on the crystal structure, electrochemical properties, and morphology of the CuO thin film electrodes. These aspects were correlated with electrochemical analyses, namely cyclic voltammetry and chronopotentiometry, as well as physical characterizations including contact angle measurements, X-ray diffraction and field emission scanning electron microscopy. Additionally, atomic force microscopy provided 3D images along with parameters such as average roughness, root mean square roughness, and average grain diameter. The CuO thin film electrodes exhibited a notable enhancement in capacitive behaviour. Specifically, the specific capacitance reached a significant value of 946 F/g at 5 mV/sec. Moreover, the highest observed specific power was recorded at 42 kW/kg during scans at 1 mV/sec. Notably, the CuO films also demonstrated commendable photo-catalytic activity in the degradation of methylene blue dye.