Self-assembly of 2D Fe-doped NiTe/NiTe2 heterostructure for boosted oxygen evolution

Abstract

Highly active and low-cost electrocatalysts composed of non-noble metal elements are essential for acquiring the green hydrogen energy through a large water electrolysis device. In this work, to accelerate the oxygen evolution reaction (OER), the Fe-doped NiTe/NiTe2 heterostructures (termed as Fe-NiTe/NiTe2) were synthesized via a facial one-step process, and further characterized by X-ray diffraction, nitrogen adsorption–desorption test, scanning and transmission electron microscopy, and X-ray photoelectron spectroscopy. The optimized Fe-NiTe/NiTe2 exhibits a low overpotential of 284 mV at J = 10 mA cm−2 with a small Tafel slope of 49 mV dec−1 and a remarkable durability within a decline of 4.93% after a long-term chronoamperometry test in alkaline electrolyte. The splendid electrocatalytic performance of Fe-NiTe/NiTe2 is ascribed to bimetallic synergy effect and heterostructure of two tellurides after compared with the corresponding catalysts (i.e., NiTe, Fe-NiTe and Fe-NiTe2). In addition, the mechanism reveals that tellurium ions can obviously increases the covalence of Ni-Te bonds and adsorption energy of OH− at the Ni sites, which will significantly promote the efficiency of water oxidation via electrocatalysis. Therefore, this study offers a feasible method for manufacturing the highly active telluride-based electrocatalysts for OER through a one-step solvothermal method.