Boosting bioelectricity generation in microbial fuel cells using metal@metal oxides/nitrogen-doped carbon quantum dots

Microbial fuel cells have recently received significant consideration from researchers worldwide as sustainable and futuristic energy due to their potential in converting energy from decomposition of natural organisms in waste to green electricity. Unfortunately, the difficulty of achieving high power due to poor extracellular electron transfer (EET) efficiency between microorganisms and the solid substrate, besides low bacterial loading capacity has limited their applications to date. Herein, iron/iron oxide (Fe@Fe2O3) nanoparticles incorporated with nitrogen-doped carbon quantum dots (NCQDs) are synthesized via using an effective and simple electrodeposition technique. Fe@Fe2O3/NCQDs anode provides not only a high effective surface area for the adhesion of microbe's cells but also promotes favored electrical conductivity to facilitate EET from bacteria to the anode in the mixed culture-based MFCs. Considerably, at a steady-state of the electricity production, the MFC equipped with Fe@Fe2O3/NCQDs as activated anode delivers a maximum power density of 836 +/- 8 mW/m(2), which is 87% higher compared to instances when NCQDs (446 +/- 11 mW/m(2)) is applied as anode electrocatalyst. This work opens a door toward an effective route to microbial anode electrode to produce sustainable green energy. (c) 2021 Elsevier Ltd. All rights reserved.