Enhanced specific capacitance of Ni foam coated Ag₂MoO₄ symmetric supercapacitor synthesized by hydrothermal method

For electrochemical performance, a number of reports are available on the asymmetric capacitor based on Ag₂MoO₄ nanoparticles. In this present work, we investigate, for the first time, the electrochemical performance of the symmetric supercapacitor on Ag₂MoO₄ nanoparticles prepared via the hydrothermal technique. In XRD, the 0.2 M Ag₂MoO₄ nanoparticles obtained the cubic crystalline structure, and their crystallite size was found to be 46 nm. Here, when Ag is doped into molybdenum oxide nanoparticles, the diffraction peaks are shifted towards lower diffraction angles due to the ionic radius of Ag⁺ (1.26 Å) being larger than Mo⁶⁺ (0.65 Å). The FTIR spectrum of 0.2 M Ag₂MoO₄ nanoparticles reveals the stretching and bending vibrations for Mo–O–Mo and Ag–O bonds at 819 and 635 cm⁻¹, respectively. In electrochemical studies, the 0.2 M Ag₂MoO₄ nanoparticles exhibited a specific capacitance of 536 F g⁻¹ at 1 A g⁻¹. Besides, the capacitance retention of 97.3% was obtained after 2000 cycles. In the EIS measurement, we observed a small semicircle, indicating a lower equivalent series resistance resulting from improved diffusion of the electrolyte and ions. In a symmetric supercapacitor, the 0.2 M Ag₂MoO₄ nanoparticles reached a voltage of 1.2 V between two identical single electrodes, with energy and power densities measured at 26.8 and 363.5 W kg⁻¹, respectively. Based on the above results, Ag₂MoO₄ nanoparticles are a good material for electrochemical applications and the development of effective energy storage devices.