Development of GO-decorated CuO and CuO/La2O3 from Garcinia mangostana for supercapacitor application

The green-mediated approach is used to create the binary and ternary nanocomposites (NCs) of CuO/GO and CuO/La₂O₃/GO from Garcinia Mangostana. The development of green chemistry resulting from the natural products of plant extracts as ceiling agents and their source of carbon for the formation of NC. In this present work, we have selected the peels from mangosteen fruit as one of the biological waste products. Mangostins are a class of α-mangostin (xanthone), flavonoids and phytochemicals that also include tannins and anthocyanins, which are found in the pericarp, also known as the “Queen of Fruits”. The synthetic samples were characterised by structural, surface, and elemental composition analysis by XRD, FTIR, SEM, EDS, XPS, and BET studies. The CuO/GO and CuO/La₂O₃/GO composite electrodes were formed in a three-electrode arrangement. Cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS) studies were employed to evaluate the performance of supercapacitors through electrochemical analysis. The supercapacitor electrode of the ternary composite, with a specific capacitance value of 447 F/g at a scan rate of 10 mV/s and 472 F/g at a current density of 1 A/g in a 6 M KOH electrolyte, has achieved a remarkable specific capacitance value compared to the binary composite. Additionally, it has demonstrated 96.2 % capacity retention with exceptional cycling stability up to 5000 GCD cycles. As a result, CuO/La₂O₃/GO composite offers a promising alternative for the development of future high-yield electrochemical supercapacitors.