Nickel Ditelluride Nanosheet Arrays: A Highly Efficient Electrocatalyst for the Oxygen Evolution Reaction

Abstract Developing efficient electrocatalysts for water oxidation is of vital importance for the electrochemical production of hydrogen (H 2 ) fuels. Herein, we report the hydrothermal synthesis of a NiTe 2 nanosheet array anchored on Ti mesh (NiTe 2 /TM) through the topotactic transformation from a Ni(OH) 2 nanoarray on the basis of an anion exchange reaction. As a robust non‐noble‐metal catalyst electrode for alkaline water oxidation, NiTe 2 /TM exhibits high activity and delivers a small overpotential of 315 mV to realize an anodic geometrical current density of 10 mA cm −2 , with superior long‐term durability. It is suggested that the NiOOH species is evolved as the active phase for water oxidation. This study reveals a very profound earth‐abundant 3D catalyst electrode for electrochemical water splitting towards large‐scale and clean H 2 evolution from water.