Fabrication of Blue Laser-Induced Graphene Electrodes and Evaluation of Their Electroanalytical Performance

Laser-induced synthesis of graphene (LIG) offers advantages of being environmental benign, scalable and highly customizable. Furthermore, graphene obtained via this methodology possess edge defects, oxygen functionalities and subsequently contain sufficient density of electronic states and are advantageous for electroanalytical applications. However, CO₂ laser possess large absorption energy and results in significant heating of the underlying substrate. Despite these limitations, the scientific literature for LIG is replete with works based on CO₂ laser. On the other hand, blue laser (405 nm) anchors graphene production via both the photothermal and photochemical effects and minimizes the problem associated with overheating of substrates. However, only few works based on blue LIG have been reported. Considering these advantages and the dearth in blue LIG works, we fabricated LIG at a particular laser setting and investigated its structural properties. The XRD and Raman spectroscopy (I_D/I_G ~ 0.9) results revealed graphene formation with excellent crystallinity (98%) and sp² hybridization characteristics thus vindicating the fabrication parameters. The SEM images revealed 3D porous structures, which has been reported by many other groups also. The electroanalytical performance was evaluated using outer sphere redox molecule, ferricyanide on a disc shaped 3-electrode system containing quasi silver reference electrode. Future works shall involve electrode design optimization on the optimized fabrication/lasing parameters to improve the electroanalytical performance of electrodes.