Interfacial Electron Distribution of Co Nanoparticles Supported on N-Doped Mesoporous Hollow Carbon Spheres Endows Highly Efficient ORR, OER, and HER

The tailoring of the charge transfer between support material and transition metal active phase is an effective strategy for fine tuning the electronic structure of the catalyst active site, and hence improving the activity and stability of the reaction. This works presents that Co nanoparticles supported on N-doped mesoporous hollow carbon nanospheres (Co/NMHCS) decouple the effect of electronic structure on catalytic performance. The detailed experimental and theoretical results reveal the charge distribution at the Co/NMHCS interface due to N-doped MHCS. With tuning the electron redistribution, the interface between Co nanoparticles and NMHCS as the active site shows the strong capability to adsorb and reduce the OOH* and proton, thus leading to the optimal ORR, OER, and HER activity in Co/NMHCS. Furthermore, Co/NMHCS-based Zn-air battery exhibits high power density of 185 mW cm(-2), and high gravimetric energy density of 753 mAh g(Zn)(-1). Density functional theory (DFT) reveals the electrons accumulate directly on the NMHCS support, which originates from an interplay between Co nanoparticles and the NMHCS support. This work provides constructive guidance for precisely regulating the interface electronic structures to achieve excellent electrocatalytic performance.