Nickel-doped nanobelt structured molybdenum oxides as electrocatalysts for electrochemical hydrogen evolution reaction

Abstract

In this work, nickel has been doped into α-MoO3 and the resulting Ni x Mo1 − x O3 nanostructured materials was examined as electrocatalysts for the cathodic hydrogen evolution reaction (HER). X-ray diffraction (XRD) analysis of the synthesized materials indicated that Ni go into the orthorhombic structure of α-MoO3 up to x = 0.2. Above x = 0.2, NiMoO4 (monoclinic) phase was formed along with the formation of trace quantities of MoO3. Nanobelt (NB) morphologies were observed for oxides with x ≤ 0.2 in transmission electron microscope (TEM) analysis and with the increase in the Ni concentration above 0.2, presence of broken belts along with few spherical particles were observed. The hydrogen evolving rates for various concentrations of Ni in MoO3 has been compared from the linear sweep voltammograms (LSVs) recorded at 500th cycle.