Materials Science 2026

Microbial fuel cells (MFCs) enable simultaneous bioenergy recovery and wastewater treatment, yet their output is frequently constrained by slow extracellular electron transfer at the anode. This study reports a flexible carbon felt anode modified with a polyaniline/reduced graphene oxide/graphitic carbon nitride (PANI/rGO/g-C₃N₄) nanocomposite, prepared by a simple drop-casting technique, and evaluated in a single-chamber, membrane-less, air-cathode MFC inoculated with a pre-cultured Pseudomonas–Bacillus consortium. The synthesized electrode was characterized for its physicochemical and electrochemical properties, and metagenomic analysis confirmed successful composite formation alongside enrichment of an electroactive microbial community at the anode surface. Cyclic voltammetry revealed well-defined redox behaviour, with an oxidation peak at +0.43 V and a reduction peak at −0.42 V, indicating active surface redox processes and strong biofilm electroactivity. The modified anode reached a specific capacitance of 0.318 F g⁻¹, attributed to effective bacterial attachment, while electrochemical impedance spectroscopy showed low internal resistance (Rs = 1.29 Ω, Rct = 49.72 Ω), consistent with improved interfacial electron transfer. The system delivered a maximum power density of 101.8 mW m⁻² together with efficient pollutant removal, achieving chemical oxygen demand (COD) reduction exceeding 96%. Concurrent degradation of methyl orange was monitored by UV–Vis spectroscopy, which showed near-complete disappearance of the characteristic 464 nm absorbance peak within 72 h. These findings demonstrate that the PANI/rGO/g-C₃N₄-modified flexible anode enhances both power generation and dye-laden wastewater treatment, supporting conductive polymer/carbon nanocomposite anodes as a practical route to higher-performance bioelectrochemical systems.

Afreen is pursuing PhD in Chemical Sciences from Universiti Sains Malaysia and is currently a visiting researcher at Northumbria University under a Commonwealth Split-Site Scholarship. Her research focuses on polymer- and carbon-based electrode materials for microbial fuel cells, electrochemical characterization, wastewater treatment, and voltammetric biosensing, spanning conducting-polymer/carbon-nanomaterial composites and their application to bioelectrochemical energy and environmental systems.