Bifunctional Electrocatalysts for Overall Water Splitting from an Iron/Nickel‐Based Bimetallic Metal–Organic Framework/Dicyandiamide Composite

Abstract Pyrolysis of a bimetallic metal–organic framework (MIL‐88‐Fe/Ni)‐dicyandiamide composite yield a Fe and Ni containing carbonaceous material, which is an efficient bifunctional electrocatalyst for overall water splitting. FeNi 3 and NiFe 2 O 4 are found as metallic and metal oxide compounds closely embedded in an N‐doped carbon–carbon nanotube matrix. This hybrid catalyst (Fe‐Ni@NC‐CNTs) significantly promotes the charge transfer efficiency and restrains the corrosion of the metallic catalysts, which is shown in a high OER and HER activity with an overpotential of 274 and 202 mV, respectively at 10 mA cm −2 in alkaline solution. When this bifunctional catalyst was further used for H 2 and O 2 production in an electrochemical water‐splitting unit, it can operate in ambient conditions with a competitive gas production rate of 1.15 and 0.57 μL s −1 for hydrogen and oxygen, respectively, showing its potential for practical applications.