Direct methanol fuel cell with enhanced oxygen reduction performance enabled by CoFe alloys embedded into N-doped carbon nanofiber and bamboo-like carbon nanotube.

The exploration of cost-effective electrocatalysts with high catalytic activity and methanol tolerance to replace precious metal catalysts in the oxygen reduction reaction (ORR) is highly desirable for direct methanol fuel cells (DMFCs). Herein, we report a novel complex composed of a CoFe alloy with a modulated electronic structure confined to nitrogen-doped carbon nanofiber (NCNF) and bamboo-like carbon nanotube (BCNT) by tuning the molar ratio of Co and Fe (CoFe@NCNF/BCNT). The synthetized catalysts possess one-dimensional (1D) mesoporous structure, high specific surface area, and rich pyridinic-N content.

Bimetal-organic framework-derived porous CoFeO nanoparticles as biocompatible anode electrocatalysts for improving the power generation of microbial fuel cells.

Hypothesis: The relatively lower power density of Microbial fuel cells (MFCs), primarily resulting from weak biofilm habitation and sluggish extracellular electron transfer (EET) at the anode interface, limits their practical implementation on a large scale. To address this challenge, porous CoFeO nanoparticles could be used as anode electrocatalysts based on the following considerations: (i) the introduction of CoFeO nanoparticles endows the anode with a rough surface that facilitates biofilm formation; (ii) the positively charged Co and Fe ions improve the interfacial affinity of anodes, enabling rapid immobilization and colonization of negatively bacteria; (iii) the multi-valent metal states of Co and Fe can function as electron shuttles, mediating EET process between biofilm and anode.

Experiments: CoFeO nanoparticles prepared with a bimetal-organic framework (B-MOF) as precursor, were modified to the surface of carbon cloth as the anode of MFCs.

Carbon nanotubes encapsulating FeS micropolyhedrons as an anode electrocatalyst for improving the power generation of microbial fuel cells.

The low power density originating from poor electroactive bacteria (EAB) adhesion and sluggish extracellular electron transfer (EET) at the anode interface, is a major impediment preventing the practical implementation of microbial fuel cells (MFCs). Tailoring the surface properties of anodes is an effective and powerful strategy for addressing this issue. In this study, we successfully fabricated an efficient anode electrocatalyst, consisting of carbon nanotubes encapsulating iron disulfide (FeS@CNT) micropolyhedrons, using simple hydrothermal and freeze-drying methods, which not only strengthened the anode interaction with EAB but also promoted the EET process at the anode interface.