Facile Route to Achieve Co@Mo2C Encapsulated by N-Doped Carbon as Efficient Electrocatalyst for Overall Water Splitting in Alkaline Media

The development of inexpensive, highly efficient and stable noble metal-free heterostructure bifunctional electrocatalysts is crucial for water electrolysis. Herein, a facile strategy is utilized by pyrolyzing the mixture containing ammonium molybdate tetrahydrate and zeolitic imidazolate framework-67 to achieve a product with Co nanoparticles as core and beta-Mo2C embedded in N-doped carbon as a shell (Co@ beta-Mo2C-NC). The Co@ beta-Mo2C-NC-0.115 (quantity of Mo precursor) composite illustrates an overpotential (eta(10)) of 188 and 330 mV for hydrogen and oxygen evolution reactions, respectively, and a cell voltage of 1.72 V is required for overall water splitting to attain a current density of 10 mA cm(-2) in alkaline media. Remarkably, the Co@ beta-Mo2C-NC-0.115 catalyst exhibits excellent stability for continuous operation of 15 h chronopotentiometry and 25 h chronoamperometry measurements. The satisfactory electrocatalytic performance can be ascribed to the unique core-shell nanostructure, especially the synergistic effect between Co, beta-Mo2C and N-doped carbon. These research findings speculate a straightforward strategy to fabricate MOF derived heterostructures with robust catalytic performance and wide applications in electrocatalysis. (C) 2020 The Electrochemical Society ("ECS"). Published on behalf of ECS by IOP Publishing Limited.