In situ coupling of Co0.85Se and N-doped carbon via one-step selenization of metal–organic frameworks as a trifunctional catalyst for overall water splitting and Zn–air batteries

摘要: Developing efficient noble metal-free multifunctional electrocatalysts is highly effective to dramatically reduce the overall cost of electrochemical devices. In this work, we demonstrate for first time a facile strategy in situ coupling ultrafine Co0.85Se nanocrystals and N-doped carbon (Co0.85Se@NC) by directly selenizing zeolitic imidazolate framework-67 (ZIF-67) polyhedra. Benefiting from synergistic effect between NC, Co–N–C structure, porous conductive network, Co0.85Se@NC affords excellent oxygen evolution reaction (OER) performance with small overpotential, remarkable stability, high faradaic efficiency. Furthermore, can also efficiently catalyze hydrogen (HER) reduction (ORR), therefore investigated its applications as trifunctional electrocatalyst water splitting Zn–air batteries. When used both anode cathode splitting, low cell voltage 1.76 V sufficient reach current density 10 mA cm−2; obtained batteries exhibit very discharge–charge gap (0.80 at cm−2) long cycle life (up 180 cycles). These results not only synthesis affordable but present huge potential clean energy systems.