Direct Laser Writing-Assisted Method for Template-Free Fabrication of Biomass-Based Porous Carbon Platelets with Uniform Size and Arbitrarily Designed Shapes

[Image: see text] Because of a wide range of applications of porous carbon platelets (PCPs), a robust method for their facile synthesis/fabrication with controlled porous structure, size, and shape is constantly needed. Herein, we report a simple and scalable method for producing PCPs with uniform size and arbitrarily designed shapes. This approach relies on CO(2) laser irradiation to induce carbonization of a biomass composite sheet formed by the infusion of sodium lignosulfonate into a cellulose paper to create porous carbon features with arbitrarily designed shapes. Upon subsequent water immersion treatment, the laser-written carbon features could spontaneously detach to form freestanding PCPs. The PCPs of different shapes were fabricated, characterized, and demonstrated for their potential applications in dye adsorption, as flexible sensors, and as miniaturized supercapacitors. Our method is expected to make great impacts in multiple fields, such as environment, energy storage, sensing, catalysis, and so forth.