Controlled synthesis of MnS/ZnS hybrid material with different morphology as efficient water and urea electrolysis catalyst

Abstract

Fabrication of earth-abundant, environmentally friendly, high-efficiency and robust bifunctional electrodes for generating hydrogen has become increasingly appealing. Herein, a series of MnS/ZnS nanohybrids grown directly on Ni foams was firstly explored at different temperatures by one-step hydrothermal method for water and urea electrolysis. When it was used as the hydrogen evolution reaction and oxygen evolution reactions catalyst, MZS/NF-180 demonstrates a small overpotentials of 223 mV and 357 mV at a considerable current density of 100 mA cm−2, respectively. Moreover, adapting it as cathode and anode electrode for water splitting in 1.0 M KOH, a low cell voltage of 1.61 V is required for delivering 10 mA cm−2 and cycling lifespan is attained for more than 12 h. Additionally, the electrochemical urea oxidation results demonstrates that MZS/NF-180 demands just cell voltage of 1.37 V (vs RHE) to achieve 100 mA cm−2 in 1 M KOH with 0.5 M urea. And urea-assisted electrolysis cell displayed a low potential of 1.51 V at 10 mA cm−2 and a good stability for a 12 h test. Besides, the theoretical calculations are also conducted to explore the detail of electrocatalyst activity in water splitting.