Laser-Induced Graphene as a Cathode Catalyst for Microbial Fuel Cell

Cathode catalysts are vital components in microbial fuel cells (MFCs) for power generation. However, the high cost of platinum (Pt), the preferred catalyst material, limits its scalability. Several efforts have been made to improve the catalytic performance of MFCs in order to replace the existing catalysts. Graphene exhibits excellent catalytic activity due to its unique physicochemical properties. However, conventional graphene fabrication methods are complex and expensive. In contrast, laser-induced graphene (LIG) offers a single-step, cost-effective approach with high conductivity and catalytic activity. This study investigates the performance of LIG derived from poly(ether sulfone) (PES)-modified carbon cloth (CC) as a cathode catalyst for wastewater treatment in MFCs. X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS), and Raman spectroscopy were used to characterize the prepared catalyst, demonstrating its unique nature and purity. Additionally, cyclic voltammetry (CV) and electron impedance spectroscopy (EIS) analysis evaluate the PES-LIG-CC's charge-transfer capacity and electrocatalytic activity. MFC with PES-LIG-CC has given a potential value (0.740 V) that was 2.1 times higher than bare CC (0.360 V) but lesser than Pt/C catalyst (1.050 V). The PES-LIG-CC cathode achieves a maximum chemical oxygen demand (COD) removal of 84% after three cycles. The finding suggests that the PES-LIG-CC catalyst for power output offers an affordable substitute for the expensive Pt/C catalysts used in MFC for wastewater treatment.