Narasimhaa Naidu Loganathan - Department of Mechanical Engineering and Centre of Innovative Nanostructure and Nanodevices​, Faculty of Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia.
Kabilashen Readdyi Munusamy - Department of Mechanical Engineering and Centre of Innovative Nanostructure and Nanodevices​, Faculty of Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia.
Veeradasan Perumal - Department of Mechanical Engineering and Centre of Innovative Nanostructure and Nanodevices​, Faculty of Engineering, Universiti Teknologi PETRONAS, Seri Iskandar, Malaysia.
Bothi Raja Pandian - School of Chemical Sciences, Universiti Sains Malaysia, Gelugor, Malaysia.

This paper reports a facile carbonization method of a biopolymer to synthesize reduced graphene oxide with excellent electrochemical properties for use as a supercapacitor electrode. Oil palm lignin is used as the biopolymer-based graphene precursor, and a carbon dioxide laser is used to carbonize the material via lithography. Using Raman Spectroscopy, the characterization of the resultant graphene (OP-LSG) revealed D, G, and ۲D peaks corresponding to multilayer graphene. Scanning Electron Microscopy of OP-LSG revealed three-dimensional particle-like fibrous and porous nanostructures with an enhanced surface area. In a three-electrode setup in ferrocyanide electrolyte, cyclic voltammetry showed the electrode coated with OP-LSG achieving a specific capacitance as high as ۱۰۸.۰۴۴ mF/cm² at a scan rate of ۰.۰۱ V/s. The galvanostatic charge-discharge of OP-LSG revealed energy and power density values of ۱۵ µWh/cm² and ۵۹۷ µW/cm² at a scan rate of ۰.۰۱ V/s. The OP-LSG electrode retained ۹۷.۵% of its initial capacitance after ۱۰۰۰ charge-discharge cycles.

Reduced graphene oxide, electric double layer capacitor, laser lithography, graphene electrode, biopolymer