Enhancing bioelectricity generation in seaweed-derived microbial fuel cells using modified anodes with Fe2O3@AuNPs/PANI nanocomposites

Harnessing the macroalgae seaweed as a feedstock for microbial fuel cells (MFCs) to generate bioelectricity represents one of the innovative approaches that have emerged from pursuing sustainable ways for addressing energy and environmental concerns. The present research explores MFC performance, biofilm formation, and organic pollutant removal, which are affected by modifying the anode via Fe2O3@AuNPs/PANI nanocomposite. A physicochemical examination of the anolyte, consisting of anaerobic sludge and seaweed hydrolysate, indicated that it was appropriate for voltage output and showed potential as an MFC substrate. Three distinct nanocomposites were created using varying quantities of iron oxide nanoparticles (Fe2O3 NPs), namely Fe2O3-1@AuNPs/PANI, Fe2O3-2@AuNPs/PANI, and Fe2O3-3@AuNPs/PANI. TEM examination demonstrated the small size of the produced nanocomposites. Meanwhile, SEM confirmed that AuNPs and Fe2O3 NPs were deposited onto the PANI surface. Among the several anode modifications that significantly affected MFC performance, the Fe2O3-3@AuNPs/PANI-CF anode exhibited the highest voltage (944 mV), power density (222.78 mW/cm³), and current density (269 mA/cm2). The modified anodes significantly improved electron transfer kinetics and electrocatalytic efficiency by applying cyclic voltammetry and electrochemical impedance spectroscopy. The electrogenic biofilm, which was thicker and had more layers, was encouraged to grow on the modified anodes. This showed that the electrons were moving more efficiently and the substrates were being used better. Additional metabolic analyses of the modified anodes showed increased microbial biomass densities and more noticeable biopolymer matrix production. This research implies that seaweed has much potential for use as a valuable resource in MFCs, offering a sustainable and environmentally friendly method of producing electricity. This emphasizes how seaweed, a ubiquitous and renewable resource, may be exploited to contribute to fulfilling global energy requirements.