Core Shell Nanocomposites Based on Gold Nanoparticle@Zinc Iron Embedded Porous Carbons Derived from Metal Organic Frameworks as Efficient Dual Catalysts for Oxygen Reduction and Hydrogen Evolution Reactions
Core shell nanocomposites based on Au nanoparticle@zinc iron embedded porous carbons (Au@Zn Fe C) derived from metal organic frameworks were prepared as bifunctional electrocatalysts for both oxygen reduction reaction (ORR) and hydrogen evolution reaction (HER) A single Au nanoparticle of 50 100 nm in diameter was encapsulated within a porous carbon shell embedded with Zn Fe compounds. The resulting Au@Zn Fe C hybrids exhibited apparent catalytic activity for ORR in 0.1 M KOH (with an onset potential of +0.94 V vs RHE, excellent stability and methanol tolerance) and for HER as well, which was evidenced by a low onset potential of 0.08 V vs RHE and a stable current density of 10 mA cm 2 at only 0.123 V vs RHE in 0.5 M H2SO4. The encapsulated Au nanoparticles played an important role in determining the electrocatalytic activity for ORR and HER by promoting electron transfer to the zinc iron embedded porous carbon layer, and the electrocatalytic activity was found to vary with both the loading of the gold.