Electrosynthesis, modulation, and self-driven electroseparation in microbial fuel cells

Iwona Gajda; Jiseon You; Buddhi Arjuna Mendis; John Greenman; Ioannis A Ieropoulos

doi:10.1016/j.isci.2021.102805

Electrosynthesis, modulation, and self-driven electroseparation in microbial fuel cells

iScience. 2021 Jul 21;24(8):102805. doi: 10.1016/j.isci.2021.102805. eCollection 2021 Aug 20.

Authors

Iwona Gajda¹, Jiseon You¹, Buddhi Arjuna Mendis¹, John Greenman¹, Ioannis A Ieropoulos¹

Affiliation

¹ Bristol BioEnergy Centre, Bristol Robotics Laboratory, T-Block, Frenchay Campus, University of the West of England (UWE Bristol), Bristol BS16 1QY, UK.

Abstract

Microbial electrosynthesis (MES) represents a sustainable platform that converts waste into resources, using microorganisms within an electrochemical cell. Traditionally, MES refers to the oxidation/reduction of a reactant at the electrode surface with externally applied potential bias. However, microbial fuel cells (MFCs) generate electrons that can drive electrochemical reactions at otherwise unbiased electrodes. Electrosynthesis in MFCs is driven by microbial oxidation of organic matter releasing electrons that force the migration of cationic species to the cathode. Here, we explore how electrosynthesis can coexist within electricity-producing MFCs thanks to electro-separation of cations, electroosmotic drag, and oxygen reduction within appropriately designed systems. More importantly, we report on a novel method of in situ modulation for electrosynthesis, through additional "pin" electrodes. Several MFC electrosynthesis modulating methods that adjust the electrode potential of each half-cell through the pin electrodes are presented. The innovative concept of electrosynthesis within the electricity producing MFCs provides a multidisciplinary platform converting waste-to-resources in a self-sustainable way.

Keywords: Chemistry; Electrochemical energy conversion; Electrochemical energy production; Electrochemistry; Engineering.

Publication types

Review