Self-assembled NiTe2 nanocrystals as highly efficient and stable electrocatalyst for hydrogen evolution reaction

Abstract

To develop high-efficient electrocatalysts with excellent stability for hydrogen evolution reaction (HER) is a crucial way to alleviate the serious energy crisis. Recently, transition metal tellurides have been reported as promising catalysts for HER. Herein, self-assembled NiTe2 nanostructures including nanocrystals (NCs) and nanoplates (NPs) were synthesized in different solvents by a facile solvothermal method. As novel electrocatalysts, NiTe2 nanostructures show highly efficient HER performance in acidic medium. Particularly, NiTe2 NCs exhibit much faster kinetics for HER. Compared with NiTe2 NPs, NiTe2 NCs demonstrate superior HER performance with a low onset overpotential of 317 mV vs. RHE and a very small Tafel slope of 36 mV dec-1, which is close to that of noble platinum (Pt) catalyst (30 mV dec-1). Moreover, it exhibits excellent stability with more than 95% high current retention after being tested for 1500 voltammetry cycles. The outstanding HER activity of NiTe2 NCs is attributed to its unique interconnection nanostructure and high conductivity. It is promising for NiTe2 NCs as a highly efficient non-noble-metal electrocatalyst to replace Pt-based materials for hydrogen evolution.