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.