TiN @ Co5.47N Composite Material Constructed by Atomic Layer Deposition as Reliable Electrocatalyst for Oxygen Evolution Reaction

An efficient and durable oxygen evolution reaction (OER) electrocatalyst consisting of TiN @ Co 5.47 N is constructed by the integration of plasma nitriding and a delicate atomic layer deposition (ALD) Co x N process. Representative results of comprehensive study are: 1) the material is electrocatalytically active in universal medium. The OER overpotentials are 398, 248, and 411 mV in acidic, basic, and neutral electrolyte, respectively, at a current density of 50 mA cm −2 ; 2) the material records an impressive long-term stability of continuous catalysis for 1500 h, during which the overpotential increases by only 1.3%. The synergistically electronic interaction between TiN and ALD Co 5.47 N, as well as a protective yet active CoTi layered double hydroxides (CoTi LDH) layer formed simultaneously at the interface/surface of TiN @ Co 5.47 N during the electrocatalytic process, is speculated to be responsible for the superior OER performance; 3) the surface Co atoms other than Ti of CoTi LDH, exhibit electrocatalytic activity with dramatically low overpotential based on density functional theory calculations.