Synthesis of Ag nanoparticles decorated MnO2/sulfonated graphene composites with 3D macroporous structure for high performance capacitors electrode materials

Abstract

An effective strategy to improve the conductivity of MnO₂-based electrodes is to combine them with some conductive materials, such as metal or carbon-based materials. In this work, Ag nanoparticles decorated MnO₂/Sulfonated Graphene composite with 3D macroporous structure (3D Ag–MnO₂/SG) was synthesized and their performance as electrode material in supercapacitors was studied. The improved conductivity and the elaborate design of 3D porous structure allowed the 3D Ag–MnO₂/SG electrode to possess enhanced electrochemical performance. For example, the electrochemical testing results demonstrated that the 3D Ag–MnO₂/SG presents a capacitance of 537 F g⁻¹ at 0.5 A g⁻¹, which is much higher than that of MnO₂ (∼172 F g⁻¹). Moreover, the 3D Ag–MnO₂/SG electrode delivers a higher capacity retention rate in high current density and smaller charge transfer resistance than that of MnO₂, which is contributed by the synergistic effect from the Ag nanoparticles and the 3D porous SG.