A Nickel(II) N′-(2-hydroxybenzylidene)morpholine-4-carbothiohydrazide Electrocatalyst for Hydrogen Evolution Reaction

In this study, a nickel(II) N′-(2-hydroxybenzylidene)morpholine-4-carbothiohydrazide complex has been evaluated as an electrocatalyst for the hydrogen evolution reaction (HER) in the presence of 0.2 M [NBu4][BF4], and deaerated DMF. The cyclic voltammetry shows two reduction peaks at -0.95 V and -1.34 V corresponding to the reduction of the couples Ni2+/Ni+1 and Ni1+/Ni respectively and the two oxidation peaks appeared at 0.68 V and 1.04 V. Additionally, the hydrogen evolution reaction was investigated using a known concentration of acetic acid. The second reduction peak was shifted to approximately 57 V relative to the free acetic acid reduction peak. The maximum activity was recorded in the presence of 31.5 equivalents of acetic acid and reached the current saturation at 235 μA.