Search

Reported herein is an active and durable CoN‐containing oxygen evolution reaction (OER) electrocatalyst which efficiently functions in a neutral medium (pH ≈7). The composite material (N, S)‐RGO@CoN is synthesized by delicate atomic layer deposition (ALD) of CoN on a nitrogen and sulfur (N, S) co‐doped reduced graphene oxide (RGO) substrate. Representative results of the comprehensive study are: 1) The flower‐like sphere RGO substrate prepared by spray drying method features rich physical and chemical properties, which are beneficial for rapid mass/charge transfer to improve the intrinsic OER process; 2) the optimal ALD material for OER tests is afforded by tuning spray conditions and ALD parameters. Versatile structural and compositional characterizations confirm uniform growth and strong chemical coupling of nanostructured CoN on (N, S)‐RGO matrix; 3) the material is electrocatalytically active and durable in a neutral electrolyte, recording an OER overpotential of 220 mV at a current density of 10 mA cm−2 and stability of 20 h continuous catalysis at 20 mA cm−2 with nearly 100% Faradic efficiency; 4) Upon the experimental studies and density functional theory calculations, the eventual mechanism of remarkable OER activity conforms to the structural fate of ALD CoN electronic coupling to the carbon substrate. [ABSTRACT FROM AUTHOR]

An efficient and durable oxygen evolution reaction (OER) electrocatalyst consisting of TiN @ Co5.47N is constructed by the integration of plasma nitriding and a delicate atomic layer deposition (ALD) CoxN 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 Co5.47N, as well as a protective yet active CoTi layered double hydroxides (CoTi LDH) layer formed simultaneously at the interface/surface of TiN @ Co5.47N 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. [ABSTRACT FROM AUTHOR]