Microstructures, optical and electrochemical properties of advanced Fe0.8Se0.14Si0.06MoO4 nanocrystalline for energy storage applications

Abstract

Abstract Technological progress has raised expectations regarding the growth of energy storage structures. Enhancing the energy density and surface area and producing a high specific capacitance supercapacitor is urgently demanded. The microstructural and optical properties of Fe0.8Se0.14Si0.06MoO4 nanocrystallites produced by the advanced sol-gel technique are investigated. XRD and TEM show that the nanocrystallites have a crystallite nanosize of 15.6 nm and a mean diameter of 14–23.6 nm for the formed monoclinic structure. The diffuse reflectance spectra of the synthesized Fe0.8Se0.14Si0.06MoO4 calcined at 650 °C for 2 h were measured in the range of 200 to 2500 nm. The type and value of the energy band gap were obtained from the diffuse reflectance spectra. Enhancing the energy density and surface area and producing a high specific capacitance of the supercapacitor is urgently required to develop unique positive and negative electroactive nanostructures. The formation of advanced Fe0.8Se0.14Si0.06MoO4 mesoporous structures with large surface areas and adjusted energy band gap could expand more electroactive locations, which supported the contact of the electrode-electrolyte and improved the ion and electron passage through the chemical reactions. The good electrochemical performance of Fe0.8Se0.14Si0.06MoO4 was exhibited with a high specific capacitance of 681.6 F g−1 at 1.0 A g−1. The specific capacitance decreased to 396.8 F g−1 after 1000 charge-discharge cycles at 1.0 A g−1. Therefore, Fe0.8Se0.14Si0.06MoO4 was suggested as a promising positive electrode material for energy storage applications.