Zr-MOF/NiS2 hybrids on nickel foam as advanced electrocatalysts for efficient hydrogen evolution.

ABSTRACT

As a typical transition-metal sulfides (TMS), nickel disulfide (NiS2) has attracted great attention in terms of hydrogen evolution reaction (HER). Howbeit, owing to the poor conductivity, slow reaction kinetics and instability of NiS2, its HER activity is still necessary to be improved. In this work, we designed hybrid structures consisting of the nickel foam (NF) as a self-supporting electrode, NiS2 derived from the sulfuration of NF and Zr-MOF grown on the surface of NiS2@NF (Zr-MOF/NiS2@NF). Due to the synergistic effect between the different constituents, the obtained Zr-MOF/NiS2@NF demonstrates ideal electrochemical hydrogen evolution ability in acidic and alkalescent environment, reaching a standard current density of 10 mA cm-2 at overpotentials of 110 and 72 mV in 0.5 M H2SO4 and 1 M KOH electrolytes, respectively. What is more, it also maintains excellent electrocatalytic durability for 10 h in both electrolytes. This work could provide a useful guidance on effectively combining metal sulfide with MOF for high-performance HER electrocatalysts.