Self-sustaining bioelectricity generation in plant-based microbial fuel cells (PMFCs) with microalgae-assisted oxygen-reducing biocathode.

Microalgae-based biocathode development was studied for the first time in a three-chamber PMFC incorporating Chlorella sorokiniana. It represents an efficient, cost-effective and eco-friendly strategy for increase oxygen availability to the cathode. Three different indoor plants viz., Epipremnum aureum, Philodendron erubescens and Anthurium andreanum were chosen for this study. Among all the PMFCs, P. erubescens showed the highest performance, with the power density and current density of 32.21 mW m⁻² and 63 mA m⁻² respectively. This represents a 31% increase with respect to previous studied bacterial biocathode and is amongst the best in PMFC research reported till date. Cyclic voltammetry (CV), dissolved oxygen (DO) and Field emission scanning electron microscopy (FESEM) analysis confirmed microalgal biocathode development. The presence of C. sorokiniana in the cathode increases the DO concentration and the oxygen reduction rate with a higher reduction current density of −16.2 mA m⁻² as compared to mechanical aeration (−5.6 mA m⁻²). Anodic microbial community structure showed a diverse bacterial consortium dominated by Firmicutes (56.84%) and Bacteroidetes (38.45%), which are known for their ability to generate bioelectricity. [ABSTRACT FROM AUTHOR]