Interfacial interaction between molybdenum phosphide and N, P co-doped hollow carbon fibers boosting the oxygen electrode reactions in zinc-air batteries

The development of highly efficient electrocatalysts with excellent stability and electrocatalytic activity for oxygen electrode reactions is important for facilitating the application of rechargeable zinc-air batteries. The interface interaction between components is one of the most important factors that affects the catalytic activity of electrode materials. Herein, N and P co-doped hollow carbon fibers embedded with molybdenum phosphide nanoparticles ([email protected], P-HCF) are elaborately fabricated as novel bifunctional electrocatalysts to study the influence of interface interaction on oxygen redox reactions in zinc-air batteries. As evidenced, a strong electron transfer is realized at the interface between N, P-HCF and MoP NPs due to their remarkable interfacial interaction, enabling the uniform combination of the nanoparticles with the doped carbonaceous matrix. More importantly, the rearrangement of electrons along the heterogeneous interface in [email protected], P-HCF endows the electrode with abundant active sites and excellent catalytic activity, thus promoting the kinetics of the oxygen electrode reactions. Based on the above merits, [email protected], P-HCF based rechargeable zinc-air batteries demonstrate improved power density of 93.8 mW cm−2 and superior cyclability of over 600 cycles. Our work emphasizes the significant role of interface chemistry between conductive carbon matrix and transition metal compounds in regulating the catalytic activity and provides a profound insight for the development of highly active and stable oxygen electrode materials.