Chapter 6 - Role of electrode engineering in microbial electrochemical technologies for bioelectricity and biohydrogen production

Abstract

Microbial electrochemical technology is a biotechnology platform that converts the chemical energy of organic waste into electrical energy or biohydrogen (bioH2)/value-added chemicals via redox reactions in microbial fuel cells or microbial electrolysis cells, respectively. The emerging field of electrode engineering provides a pioneering explication to surmount the constraints of the conventional process for valorization. The efficacy of the conversion depends on the cathodic and anodic material or electrode used along with the interface of inoculated bacteria. Based on biocompatibility, the electrodes or materials have the capacity to enhance the microbial metabolism, increasing the overall system redox and product formation. This chapter focuses on the progressive role of engineered electrodes and their composites for enhancing or modifying the electrode surface area, toward increased electron flux, conductivity, and strength for profound bacteria–electrode interaction for bioelectricity and bioH2 production. The chapter also encapsulates the role of promising materials (carbon-based, composite-based, and metal-modified electrodes) enriching the performance of biological systems by efficient extracellular electron transport from microbes to electrodes along with direct electron transfer among species. Moreover, it focuses on increasing the electron flux, catalytic activity, kinetics, and redox stability of the electroactive microorganisms with specified electrode and material modifications for suitability toward bioelectricity and bioH2 generation.