Characterizations of synthesized laser-scribed graphene/molybdenum disulfide (LSG/MoS2) hybrids for supercapacitor performance

A sustainable and organic energy storage system from oil palm lignin waste-derived laser-scribed graphene embedded with molybdenum disulfide (LSG/MoS2 ) is reported in this work. LSG/MoS2 hybrids were fabricated to overcome the zero-band gap of graphene, and molybdenum disulfide restacking issues, and to induce electrical conductivity. Various amounts of LSG (0.1,0.5,1.0 g) were added in a MoS2 precursor to produce a nanoscale LSG/MoS2 hybrid nanostructure via the hydrothermal method. The Raman D, G, and 2D bands of LSG confirmed the formation of graphene from lignin. The FESEM morphology of LSG/MoS2 hybrids showed a porous and large surface area anchored with 3D MoS2 nanoflower on LSG. TEM imaging revealed MoS2 decorated LSG with a lattice spacing of 0.62 and 0.27nm, corresponding to the (002) and (100) planes of MoS2 . In terms of electrochemical performance, LSG with 0.1g of MoS2 has the lowest resistance, the highest specific capacitance of 6.7mF/cm2 at 0.05 mA/cm2, and excellent cyclic stability of 98.1% over 1000 cycles, based on Electrochemical Impedance Spectroscopy (EIS), Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests.