Fabrication of hierarchical Co(OH)2@Ni(OH)2 core-shell nanosheets on carbon cloth as an advanced electrocatalyst for oxygen evolution reaction

Abstract Transition metal-based layered double hydroxides have been reported as cost-effective and efficient oxygen evolution reaction (OER) catalysts due to their layered structure and unique redox properties. Moreover, the electrochemical performance can be greatly enhanced by rational design of nanostructures. Herein, the hierarchical Co(OH)2@Ni(OH)2 core-shell nanosheets on flexible carbon cloth (CC) were designed and prepared as advanced OER catalysts. Compared with the commercial RuO2, the Co(OH)2/CC and the Ni(OH)2/CC, the Co(OH)2@Ni(OH)2/CC hybrid electrode exhibits outstanding OER electrocatalytic activity with only ~330 mV at a current density of 10 mA cm−2. Moreover, the Co(OH)2@Ni(OH)2/CC catalyst shows long-term durability without obvious degradation over 10 h. The outstanding electrochemical performance of the Co(OH)2@Ni(OH)2/CC could be attributed to the unique 3D hierarchical core-shell structure and the synergistic effect between Co(OH)2 and Ni(OH)2. Our work offers an effective strategy to prepare advanced electrode materials for OER electrocatalysts.