Pt nanoparticles embedded metal-organic framework nanosheets: a synergistic strategy towards bifunctional oxygen electrocatalysis

To meet the increasing demands for highly active electrocatalysts towards oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), here in this work, a new strategy of synergistic nano-architecture design based on Platinum nanoparticles (Pt NPs) and ultrathin two-dimensional (2D) metal-organic frameworks (MOFs) is developed for bifunctional electrochemical catalysts. Compared with commercial Pt/C and RuO2 catalysts, remarkable enhancements in activity and durability of both oxygen reduction and oxygen evolution reactions are achieved on our PtNPs@MOFs composite materials, with one of the lowest over-potential gaps (Egap) of 665 mV that has ever been reported. The tests on the assembled Zn-air batteries have revealed promising electrocatalytic performance and practical advantage of our new materials as air cathode catalyst. Both experimental results and theoretical study have confirmed the synergistic effect between Pt NPs and MOF nanosheets through a “win-win” electron structural modification, demonstrating the effectiveness of our strategy in developing effective bifunctional oxygen electrocatalysts for various types of electrochemical devices.