Synthesis, structure and electrochemical properties of novel ternary composite reduced-graphene oxide/Ag nanoparticles/poly(p-phenylenediamine)

Novel ternary composite reduced-graphene oxide/Ag nanoparticles/poly(p-phenylenediamine) (rGO/Ag NPs/PpPD, GMP) is first designed, synthesized and demonstrated. Nanocomposite rGO/Ag NPs is prepared by in situ simultaneous reduction of [Ag(NH3)(2)] thorn and GO, and then a thin layer of PpPD is coated on the surface of ternary composite by polymerization. In this study, Ag NPs are no longer just designed as a typical dopant to improve conductivity, but can contribute the pseudocapacitance for composite. As a result, the obtained composite GMP-1,5,4 delivers an excellent areal capacitance of 2779 mF cm(-2) (926 F g(-1)) at 1 mA cm(-2) and a good rate capability (1639 mF cm(-2) at 40 mA cm(-2)). Meanwhile, the design of composite is indeed an effective strategy for combating the low cycling stability. For comparison, GMP-1,5,4 maintains 89.42% of the initial specific capacitance after 2000 cycles, while only 52.24% for GM-1,5 is left after 500 cycles. Additionally, it is found that ammonium persulfate (APS), a typical initiator for polymerization, may oxidize Ag NPs when its concentration is low. Therefore, our study will be of great help to researchers who will synthesize polymer/Ag NPs composite in the future. (C) 2018 Elsevier B.V. All rights reserved.