Metal-Organic Framework-Derived Hierarchical (Co,Ni)Se 2 @NiFe LDH Hollow Nanocages for Enhanced Oxygen Evolution.

High-efficient electrocatalysts are crucial for fuel cell applications; however, the whole cell performance is generally restricted by the anodic part because of the sluggish kinetics involved in the oxygen evolution reaction (OER) process. Herein, a hierarchical hollow (Co, Ni)Se2@NiFe LDH nanocage was synthesized by deriving from metal-organic framework (MOF) of ZIF-67. Concretely, it involves first fabrication of hollow rhombic (Co, Ni)Se2 nanocages and then deposition of NiFe layer double hydroxide (NiFe LDH) nanosheets on the surface of nanocages. Notably, the incorporation of Ni into Co-based ZIF-67 (via ion-exchange) could tail the atomic arrangement of the MOF, exposing more additional active sites in the following selenization treatment. The as-synthesized (Co, Ni)Se2@ NiFe LDH demonstrates splendid OER performance with a small overpotential of 277 mV (to launch a current density of 10 mA cm-2), a small Tafel slope of 75 mV dec-1, and a robust durability (a slight stability decay of 5.1 % after 17 h continuous test), not only surpassing the commercial the commercial RuO2, but also being comparable/superior to most reported non-previous metal-based catalysts. Upon analysis, the outstanding OER performance is attributed to the optimized adsorption/desorption nature of iron and nickel/cobalt towards the oxygenated species, and partial delocalization of spin status at the interface via the bridging O2-. This work represents a solid step toward exploration of advanced catalyst with deliberate experimental design and/or atoms tailoring.