One-Step Hydrothermal Synthesis of MoO₂/MoS₂ Nanocomposites as High-Performance Electrode Material for...

By only changing the ratio of Mo to S source, a distinctive single phase MoO₂ or MoS₂ and MoO₂/MoS₂ nanocomposites (NCs) are obtained through a simple one-step hydrothermal method based on CH₄N₂S as a sulfur source and (NH₄)₆Mo₇O₂₄·4H₂O as a source of Mo in oxalic acid. The effect of ratio of Mo to S source on the composition, structure, and electrochemical performance are systematically researched. Due to its unique design, abundant macropores active sites in MoO₂/MoS₂ NCs induce superior rate property (55.30% capacitance retention to 20 from 1 A g^-1) and larger specific capacitance (1667.3 F g^-1 at 1 A g^-1) and longer cycle life (94.75% after 5000 cycles) as used directly as an electrode. Furthermore, at a power density of 225 W kg^-1, a maximal energy density of 21.85 Wh kg^-1 is provided by the asymmetric supercapacitor (MoO₂/MoS₂//AC). The capacitance of asymmetric supercapacitor (ASC) is remarkably enhanced by 129.02% under 5000 cycles at a current density of 1.5 A g^-1, demonstrating outstanding cycle property. These results imply the prepared MoO₂/MoS₂ NCs have promising applications in advanced energy storages. It is important and should be noted that NCs of oxide and sulfide are prepared with only a simple one-step process.