Amorphous Porous Molybdenum Dioxide as an Efficient Supercapacitor Electrode Material

Molybdenum dioxide (MoO2) with amorphous and porous nanostructure is synthesized via a facile hydrothermal methodology in a short reaction time and used as a supercapacitors electrode material. X-ray diffraction, transmission electron microscopy and cyclic voltammetry, galvanostatic charge-discharge measurements, and cycle stability tests of the amorphous and porous MoO2 are investigated. The novel-innovative structure conduces to the high specific capacity of 444.7 F g(-1) at 1 A g(-1) in 0.5 m H2SO4 solution. After 1000 cycles, 92% capacity is retained, indicating that the as-prepared electrodes possess excellent stabilities. Furthermore, at a high current density of 8 A g(-1), the capacity can reach 210.67 F g(-1), exhibiting outstanding rate characteristics. The amorphous and porous MoO2 achieves preeminent electrochemical performance, which can be attributed to the short ion diffusion routes and can provide reversible and fast faradic reactions and the porous structure will increase the utilization of the electrode materials. Besides that, the amorphous and porous MoO2 will let each MoO2 nanoparticles to participate in electrochemical reactions due to the full contact between electrolyte and MoO2. Therefore, MoO2 will be a promising anode material for aqueous supercapacitors.