Co3O4@Cu‐Based Conductive Metal–Organic Framework Core–Shell Nanowire Electrocatalysts Enable Efficient Low‐Overall‐Potential Water Splitting

In the work reported herein, the electrocatalytic properties of Co3O4 in hydrogen and oxygen evolution reactions have been significantly enhanced by coating a shell layer of a copper‐based metal–organic framework on Co3O4 porous nanowire arrays and using the products as high‐performance bifunctional electrocatalysts for overall water splitting. The coating of the copper‐based metal–organic framework resulted in the hybridization of the copper‐embedded protective carbon shell layer with Co3O4 to create a strong Cu−O−Co bonding interaction for efficient hydrogen adsorption. The hybridization also led to electronically induced oxygen defects and nitrogen doping to effectively enhance the electrical conductivity of Co3O4. The optimal as‐prepared core–shell hybrid material displayed excellent overall‐water‐splitting catalytic activity that required overall voltages of 1.45 and 1.57 V to reach onset and a current density of 10 mA cm−2, respectively. This is the first report to highlight the relevance of hybridizing MOF‐based co‐catalysts to boost the electrocatalytic performance of nonprecious transition‐metal oxides.