Hydrogen production performance of novel glycerin-based electrolytic cell

Mesoporous cobalt oxide/nickel foam (NF) is got by a simple chemical method, and a glycerin-based electrolytic cell is rationally assembled with CoO/NF, in which glycerin-KOH aqueous solution is used as electrolyte. Herein, the influence of anodic glycerin oxidation on cathodic hydrogen production is investigated mainly. At 1.35 V vs. reverse hydrogen electrode (RHE), CoO/NF electrode exhibits a current density of 235.71 mA cm−2 for glycerin oxidation, which is about 2.5 times higher than that over Co3O4/NF. For glycerin oxidation, the Tafel slope (189 mV dec−1) over CoO/NF is much lower, compared to that (286 mV dec−1) over Co3O4/NF, demonstrating the robust electrocatalyic reaction kinetics over CoO/NF. For glycerin-contained electrolytic cell, a cell voltage (1.672 V) is needed to reach 50 mA cm−2, which is obviously lower than that (1.975 V) for conventional electrolytic cell. It is obvious that for glycerin-contained electrolytic cell, the required cell voltage has obviously decreased by 0.303 V. This work demonstrates that the substitution of glycerin oxidation for sluggish four-electron OER reaction can greatly promote water electrolysis to hydrogen production. Moreover, this design can not only degrade environmental pollutants, but also produce clean energy, and the reported strategy is obviously environment-benign and cost-effective.