UV Laser-Induced Graphene Electrode for Supercapacitor and Electrochemical Sensing Applications

Laser-induced graphene is an emerging technique for patterning few-layer graphene on a flexible substrate. Graphene is widely used in electrochemical sensors due to its high surface area and fast heterogeneous charge transfer property. This study reports a graphene-based interdigitated electrode sensor developed on a flexible polyimide tape by direct UV laser engraving technique at atmospheric conditions with low cost. Cyclic voltammetry measurements in the redox probe resulted in distinct oxidation and reduction peaks, which indicates an exemplary electrochemical behavior of the sensor. The supercapacitor was assembled with the laser-induced graphene interdigitated electrode in different electrolytes (KOH and NaOH) and the electrochemical characterization was performed. At 50 mVs⁻¹, the interdigitated electrode’s specific capacitance calculated by the cyclic voltammetry curve were 8.14 mF/cm² and 6 mF/cm² in KOH and NaOH electrolytes, respectively. The graphene electrodes also exhibited a stable response in all the studies. These results validate the potential of laser-induced graphene in patterning electrochemical devices on flexible substrates.