Exploring graphene structure, material properties, and electrochemical characteristics through laser-induced temperature analysis

Laser-induced graphene (LIG) is a three-dimensional graphene structure fabricated through the irradiation of a polymer substrate with laser energy (or fluence, equivalently). This methodology offers a cost-effective and facile means of producing 3D nanostructures, yielding graphene materials characterized by extremely high surface area and superior electrical properties, rendering them advantageous for various electrochemical applications. Nonetheless, it is imperative to acknowledge that the structures and material properties of LIG are subject to substantial variations contingent upon processing parameters, thereby underscoring the necessity for systematic inquiry and systematic comprehension of processing conditions, such as fluence and multi-passing, and resultant outcomes. Herein, we explored the impact of different laser fluence levels on the structural and material properties of LIG. We, especially, focused on how laser fluence affected substrate temperature and found that it caused polyimide (PI) substrate pyrolysis, resulting in changes in 3D structures and material density to LIG properties. We also investigated the effects of a multi-passing process on 3D LIG structures and material qualities, varying fluences, and temperature fluctuations. Lastly, we assessed electrochemical properties using LIGs produced under different conditions as working electrodes, leading to distinct impedance profiles and cyclic voltammetry (CV) curves. These variations were linked to the unique structural and material characteristics of the LIG samples.