Nanoflower-like MoS2 anchored on electrospun carbon nanofiber-interpenetrated reduced graphene oxide as a microbial fuel cell anode achieving high power density

Abstract

Weak biofilm colonization and sluggish extracellular electron transfer (EET) between the biofilm and anode are major obstacles to achieving high power density in microbial fuel cells (MFCs). Tailoring the interfacial properties of anodes using efficient electrocatalysts is considered to be a feasible strategy to overcome these limitations. In this study, a novel three-dimensional anode electrocatalyst, consisting of carbon nanofiber (CNF) interpenetrated reduced graphene oxide (rGO) for templating the growth of MoS₂ nanoflowers (rGO/CNF@MoS₂), was prepared by electrospinning, pyrolysis, freeze-drying and hydrothermal methods. The as-produced interconnected rGO/CNF@MoS₂ scaffold provided significantly rougher surfaces, large electrochemical surface area, good electrical conductivity, and abundant electroactive sites, which favored biofilm adhesion and viability and increased the EET efficiency. Hence, MFC equipped with the rGO/CNF@MoS₂ modified anode achieved an outstanding power density of 3584 mW m⁻² at a current density of 8220 mA m⁻², which was significantly higher than that achieved with similar cells comprising rGO/CNF-modified (2992 mW m⁻²), CNF@MoS₂-modified (2560 mW m⁻²), and pure carbon cloth (805 mW m⁻²) anodes. Considering its facile fabrication, excellent electrocatalytic activity in biofilms, and high power generation ability, our developed rGO/CNF@MoS₂ electrocatalyst shows considerable potential as an ideal anode electrocatalyst for achieving high MFC performance.