EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

Graphene materials are competitive candidates as electrodes of supercapacitors and other energy storage devices due to their high specific surface area, electrical conductivity and stability. Either heteroatoms doping or incorporation with metal/metal oxides have been reported effective in further improving the capacitive performance of graphene-based electrodes. In this study, a low temperature and environmentally friendly active-screen plasma (ASP) technique has been applied to graphene oxide (GO) to multi-functionalise graphene oxide with simultaneous nitrogen doping and noble metal (Pt and Au) incorporation.

Systematic microstructural characterisation was conducted to study the morphology, chemistry and structure of plasma multi-functionalised graphene oxide using SEM, HRTEM and XPS; both electrical and super-capacitive performances of the plasma treated GO samples were evaluated using four-point probe sheet resistance measurement and the electrochemical measurements including CV, EIS and GCD tests.

The results demonstrate that the ASP treatment can effectively reduce GO into rGO doped with N atoms and incorporated with nano Pt and Au particles. The sheet resistance can be reduced from 5000000 for pristine GO through to 600000 for N plasma treated GO to 400 Ohm sq-1 (about 4 orders magnitude reduction) for the N/Au incorporated GO. The capacitance measure at a scan rate of 20 mV/s increased from 80 for pristine GO through to 480 for N plasma treated GO, and to 1000 and 1300 mF (representing a >16 times improvement) for N/Pt and N/Au incorporated GO respectively.

Clearly, the advanced ASP technique is a simple and facile way for a simultaneous reduction and nitrogen doping of GO with incorporation of Au/Pt nanoparticles for energy storage applications.