Development of Laser-Induced Graphene-Based Bioanode Incorporating Thylakoid for Harvesting Energy

Thylakoid-Based Biofuel Cells (TBFCs) present significant potential as renewable power sources; however, their development is impeded by challenges including delicate thylakoid membranes, limited electron transport efficiency, stability and dependence on expensive mediators. This study aimed to address these challenges by fabricating a novel photo-driven bioanode through the integration of Laser-Induced Graphene (LIG), Nb4C3Tx MXene, and thylakoid membranes. The fabrication process involved laser engraving to generate porous LIG electrodes, followed by MXene drop casting and thylakoid immobilization to enhance electrochemical performance and surface area. Morphological characterization supported that MXene incorporation increased active sites and surface roughness, favorable for electrochemical reactions. Electrochemical analysis using cyclic voltammetry and electrochemical impedance spectroscopy revealed that the composite bioanode exhibited significantly reduced charge transfer resistance and improved redox kinetics compared to LIG electrodes. The electron transfer process was determined to be diffusion-controlled, indicating effective interaction between the electrolyte and electrode surface. Photoelectrochemical measurements illustrated enhanced photocurrent generation under illumination, confirming the bioanode capability for efficient light-driven electron transport. The photocurrent response was reproducible across multiple trials, indicating reliability and stability of the thylakoid integrated bioanode. Polarization and power density plot further validated improved energy conversion efficiency. The bioanode was successfully integrated into a complete TBFC with a gas diffusion platinum cathode to power a light emitting diode.