Laser Fabrication of Textile-Based Electrodes for Electrochemical Dye Removal

Efficient removal of toxic and persistent dyes from water is crucial for water purification. A promising approach involves using carbon-based electrodes for electrolysis. In this process, increasing the electrode surface area enhances the interfacial contact between the electrode and the solution, thereby improving dye removal efficiency. Accordingly, electrode materials with high electrical conductivity and a large surface area are desired to further enhance dye removal efficiency. In this study, we report the fabrication of conductive and porous structures directly on textiles via laser-induced graphitization. Porous graphitic carbon structures were fabricated by laser irradiation of textiles immersed in a lignin dispersion, which induced laser-induced graphitization in the irradiated area. The fabricated structures were successfully applied as electrodes for the electrolytic removal of the model dye, methyl orange (MO), from an aqueous solution. Lignin was used as both a carbon precursor and a flame retardant by immersing the textiles in a lignin dispersion prior to laser irradiation. By controlling lignin concentration and laser irradiation conditions, graphitic carbon structures were fabricated that retained the macroscopic fiber bundle morphology and exhibited microscale porosity on bundle surfaces. The fabricated electrodes with high electrical conductivity and a porous structure enabled electrolytic removal of MO. Among the conditions investigated, electrodes fabricated at 10 wt% lignin and a laser scanning speed of 100 mm/s showed the highest removal amount (0.99 mg/g). The proposed method offers a facile, one-step route for fabricating water purification devices capable of efficient dye removal from aqueous solutions using laser irradiation on lignin-immersed textiles.