Synthesis of ternary graphene/molybdenum oxide/poly(p-phenylenediamine) nanocomposites for symmetric supercapacitors

Abstract

A novel ternary graphene/molybdenum oxide/poly(p-phenylenediamine) nanocomposite (GMP) has been successfully synthesized via a two-step process including the generation of binary graphene/MoO₃ composites through a hydrothermal method and chemical polymerization of p-phenylenediamine (pPD) monomer. When the feed ratio of pPD to Na₂MoO₄·2H₂O is 1, the resulting composite (GMP-1.0) possesses superior electrochemical performance with a maximum specific capacitance of 1042.6 F g⁻¹ at 1 A g⁻¹ in a three-electrode system and 418.5 F g⁻¹ at 1 A g⁻¹ in a two-electrode system. Its energy density achieves 24.56 W h kg⁻¹ at a power density of 325 W kg⁻¹, and 6.8 W h kg⁻¹ at a high power density of 3263 W kg⁻¹. Furthermore, the ternary composite retains 86.7% of the initial capacitance after 3000 cycles, indicating its excellent cycling stability.