Molybdenum as cathode materials: Paving the way for sustainable biohydrogen production in microbial electrolysis cells

Microbial electrolysis cells (MECs) have garnered significant attention for their potential in sustainable hydrogen production and wastewater treatment. Due to their unique electrochemical properties, molybdenum-based compounds have emerged as promising candidates among various cathode materials. This review explores the multifaceted role of molybdenum in MECs, focusing on its catalytic performance, synthesis strategies, and potential for enhancing H₂ evolution reactions. Various molybdenum-based materials, including molybdenum disulfide (MoS₂), molybdenum phosphide (MoP), molybdenum carbide (Mo₂C), and nickel-molybdenum alloys (NiMo), are discussed in terms of their synthesis methods, electrochemical performance, and scalability. Notably, molybdenum-based electrodes have demonstrated comparable or superior catalytic activity to traditional platinum-based cathodes, highlighting their potential as cost-effective alternatives. Future directions in this field include further optimization of synthesis methods, exploration of new molybdenum-based cathodes, mechanistic understanding of catalytic activity, and addressing scalability and stability challenges. Overall, molybdenum-based materials present promising opportunities for advancing MECs technology, driving progress toward sustainable hydrogen production and wastewater treatment.