RESUMO
Practical applications of Zn-air batteries are usually limited by sluggish kinetics of oxygen reduction reaction. Replacing Pt-based catalysts with convenient, efficient and low-cost materials to boost oxygen reduction reaction is highly desirable. Herein, a class of Fe-N co-doped carbon nanofibers is successfully synthesized by pyrolysis of polyacrylonitrile/metal-containing ionic liquid-based electrospun films. The ionic liquids act as porogen to provide multiscale pores as well as activator to bring carbon nanofibers active sites. The catalyst possessing appropriate active sites and unique 3D porous architecture exhibits remarkable long-term stability and electrocatalytic activity. Particularly, the catalyst maintains a shape of membrane after carbonization, manifesting its direct use as air electrode without binders. It is notable that an all solid-state Zn-air battery based on the carbon nanofibers exhibits good flexibility, indicating its promising application as wearable devices.
RESUMO
This study describes a self-doping and additive-free strategy for the synthesis of metal-nitrogen-doped porous carbon materials (CMs) via carbonizing well-tailored precursors, metal-containing ionic liquids (M-ILs). The organic skeleton in M-ILs serves as both carbon and nitrogen sources, while metal ions acts as porogen and metallic dopants. A high nitrogen content, appropriate content of metallic species and hierarchical porosity synergistically endow the resultant CMs (MIBA-M-T) as effective electrocatalysts for the oxygen reduction reaction (ORR). MIBA-Fe-900 with a high specific surface area of 1567â m2 g-1 exhibits an activity similar to that of Pt/C catalyst, a higher tolerance to methanol than Pt/C, and long-term durability. This work supplies a simple and convenient route for the preparation of metal-containing carbon electrocatalysts.
