High performance supercapacitors based on samarium molybdate/nitrogen and phosphorous co-doped reduced graphene oxide electrodes

摘要

Nanocomposites produced with samarium(Ⅲ) molybdate/N, P co-doped reduced graphene oxide (Sm_2MoO_6/NPRGO) combination may be very useful in the field of supercapacitors due to the active interaction between these two components. In this study, we used the sonochemical method, which is quite simple and cheap, to produce Sm_2MoO_6/NPRGO nanocomposite, which draws attention with its high-quality electrochemical performance. Surface and structural properties of Sm_2MoO_6 nanoparticles, NPRGO and Sm_2MoO_6/NPRGO nanocomposite structures were studied by X-ray photoemission spectroscopy (XPS), nitrogen adsorption/desorption studies, scanning electron microscopy, and X-ray diffraction analysis. The symmetric supercapacitive performance of the Sm_2MoO_6/NPRGO electrode exhibits a specific capacitance of 689 F g~(-1) (at 2 mV s~(-1)) and could maintain 99.9% capacity after 4000 charge-discharge cycles. Additionally, the symmetric supercapacitors based on nanocomposite electrode demonstrate a high energy density (23.2 W h kg~(-1) at 250 W kg~(-1)), outstanding power density (8000 W kg~(-1) at 14.4 W h kg~(-1)). Generally, this nanocomposite was synthesized for the first time and its supercapacitive properties were investigated. The nanocomposite electrode exhibited good supercapacitor response, remarkable rate performance and excellent cycling stability in both 0.5 M Na_2SO_4 electrolyte.