Hydrogen production from wastewater using interdigitated printed electrode-based Single-Chamber microbial electrolysis cells

In the ever-increasing quest for alternative energy sources, hydrogen emerged as a promising green option, but efficient and economical production and management have been the primary constraints. Converting wastewater into H2 and other forms of energy attracted significant attention in terms of simultaneously and sustainably managing both the wastewater and the energy generation problems. Microbial Electrolysis Cells (MEC) evolved recently as promising options for converting wastewater into H2 and electricity but with serious constraints on scalability. The current research aims to explore design and manufacturing solutions to build structurally strong and electrochemically effective electrodes that can also lead to scalable MEC. Two designs based on the interdigitated and spiral electrode architectures are proposed and evaluated. The added design freedom with additive manufacturing by selective laser melting of specific alloys of choice is effectively utilised in physically prototyping the interdigitated and spiral electrode forms designed with controlled porosity constraints. Microstructural, electrochemical, and cell performance characterisations led to the understanding that the spiral electrode configuration with polypyrrole-coated stainless steel 316L anode is a promising design option for both longitudinal and lateral scale-up of the MEC.