Porous 3D Graphene from Sustainable Materials: Laser Graphitization of Chitosan

Laser-fabrication of graphene from cellulose-based feedstock materials often requires extensive preprocessing. This work demonstrates laser fabrication of porous, 3D graphene from a new class of marine-based sustainable materials-chitosan biopolymers. The biopolymer films contain only chitosan, acetic acid, glycerol, and water. Fourier transform infrared spectroscopy studies indicate that the cured chitosan films still retain a significant water content (?30%), enabling production of flexible films. A simple 3-step laser fabrication process is presented using low-cost infrared (CO, 2.1 W) and visible (405 nm, 0.5 W) hobbyist laser engravers, with measured sheet resistance values as low as 40 ohms sq.. Transient electrochemical detection of an inner sphere redox molecule is demonstrated using a graphene-like carbon working electrode fabricated on a water-soluble chitosan substrate.