In-situ growth of N@MoO2 microflowers on carbon cloth for high-performance anodes in microbial fuel cells

Abstract

Anode is a crucial component enabling microbial fuel cells (MFCs) to achieve efficient and durable power generation; however, the preparation of high-performance and up-scaling anodes via facile methods remains a practical challenge. In this study, a nitrogen-doped carbon cloth grafted with molybdenum dioxide microspheres (N @ MoO2/CC) was fabricated using a facile two-step method: in situ polymerization and high-temperature carburization. N @ MoO2/CC exhibited excellent bioelectricity harvesting capacity owing to its dual function of promoting bacterial colonization while enriching electroactive bacteria. The synergy of N-doping and MoO2-grafting enabled the development of a biocompatible interface for bacterial adhesion, resulting in a high bacterial loading capacity. Furthermore, N-doping and MoO2-grafting modifications facilitated the enrichment of Geobacter, thereby enhancing the electrocatalytic activity of the electrode. MFC equipped with N @ MoO2/CC achieved a maximum power density of 3.01 ± 0.23 W·m−2, i.e., 1.43 times the power density achieved using a pristine carbon cloth (2.10 ± 0.04 W·m−2). Additionally, the physical and electrochemical characterizations confirmed that the as-prepared N @ MoO2/CC exhibited excellent operational stability. In summary, N @ MoO2/CC could significantly enhance bacterial colonization, enable electroactive bacteria to flourish, and boost charge transfer efficiency at the microbe–electrode interface, thus improving the electricity generation in MFCs.