Optimization of MoO3 microstructures through temperature control and KOH activation for improved supercapacitor electrode performance

Abstract Supercapacitors are vital for modern energy storage systems due to their high power density and long operational lifespan. In this study, we investigate the use of molybdenum trioxide (MoO 3 ) microstructures for supercapacitor applications. MoO 3 exhibits favourable properties such as low serial resistance, high conductivity, and the possibility of high surface area. These properties enhance the overall electrochemical performance of such supercapacitors. The study focuses on optimizing MoO 3 preparation via oxidation at various temperatures. It was found that the orthorhombic phase of MoO 3 , formed at 500 °C, provided the best performance with a specific capacitance of 179.2 F/g (933 mF/cm 2 ) and the lowest serial resistance. Furthermore, the chemical activation of the surface by immersion in 1 M potassium hydroxide significantly increased the surface area, as confirmed by scanning electron microscopy. This hydroxide activation also led to a rise in specific capacitance, reaching 201.7 F/g (902 mF/cm 2 ). The findings presented in this work suggest that the combination of optimal oxidation conditions and surface activation via KOH immersion can lead to enhanced energy storage capacity in such supercapacitor structures. Graphical abstract