LAUSR

Oxygen evolution reaction (OER) with sluggish kinetics represents the key half-cell reaction for some sustainable energy systems, such as electrochemical water splitting, fuel cells and rechargeable metal-air batteries. Two-dimensional transition metal hydroxides present the fine proceeds for OER. Here, we designed a novel two-dimensional hierarchical FeLDH(FeCo)/Co(OH)2 arrays via the growth of 2D-ZIF-67 on carbon cloth, transformation of 2D-ZIF-67 to Co(OH)2 and electrodeposition of FeLDH(FeCo) on Co(OH)2 under ambient temperature. The optimized hierarchical catalyst exhibits high OER activity which requires small overpotential of only 242 mV to drive 10 mA cm-2 (279 mV for 100 mA cm-2), and a durablity for prolonged 100 h at 20 mA cm-2 in 1 M KOH. Studies prove that the interfaces among FeLDH(FeCo)/Co(OH)2 represents the electro catalytic active center for OER. The specific interfaces contribute to accelerate the OER kinetics with respect to the fast transition of intermediate oxygen species. Besides, FeCo alloy favors the promotion of electron transfer among the newly formed interfaces that related to CoOOH under OER process, which leads to the improved durability for OER. Our work gives enlightenment on the design and synthesis of hierarchical bimetallic hydroxides array with high-performance activity and durability, and understanding the origin of the promotion of metal and metal hydroxides for OER.