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

Developing efficient electrocatalysts for water oxidation is of vital importance for the electrochemical production of hydrogen (H2) fuels. Herein, we report the hydrothermal synthesis of a NiTe2 nanosheet array anchored on Ti mesh (NiTe2/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, NiTe2/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 H2 evolution from water.