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

In this work, nickel has been doped into α-MoO₃ and the resulting Ni _x Mo_1 − 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.