Hydrogen production by electrocatalytic water splitting promises a green and sustainable technology to address serious energy crisis and environmental pollution [1].As well known, the process of electrocatalytic water splitting is composed of two half reaction, i.e.oxygen evolution reaction (OER) at the anode and hydrogen evolution reaction (HER) at the cathode [2].The efficiency of water electrolysis is generally impeded by the sluggish OER process that originates from the multiple proton coupled electron transfer [3].