Impact of Electrode Material on Microbial Electrolysis

Annually, the budget allocated to developing new or improving existing green technologies continues to rise, reflecting the growing demand and their potential to address ongoing environmental challenges. Among these technologies, Microbial Electrolysis Cells (MECs) play a pivotal role in concurrently treating wastewater and producing (bio)hydrogen at the anode and cathode, respectively, with the assistance of electroactive microorganisms as biocatalysts. As the anode serves as the system’s driving force, selecting or adapting an appropriate electrode material with desirable characteristics like biocompatibility, chemical stability, non-corrosiveness, electrical conductivity, low resistance, affordability, and porosity is crucial. These attributes promote bacterial adhesion while facilitating electron transfer and flow. Conversely, the cathode must offer a flexible platform for hydrogen evolution reactions (HER) in MECs. Hence, researchers have explored various cathode materials as more cost-effective alternatives to metal-based catalysts, emphasizing sustainability and the reduction of HER overpotential. This chapter provides a review of diverse electrode material designs and types investigated to enhance both substrate oxidation and hydrogen production in MECs.