Nanohybridization of MoS2 with Layered Double Hydroxides Efficiently Synergizes the Hydrogen Evolution in Alkaline Media

Hydrogen evolution reaction (HER) on earth-abundant molybdenum disulfide (MoS2) in acidic media is a robust process, but is kinetically retarded in alkaline media. Thus, improving the sluggish kinetics for HER in alkaline media is crucial for advancing the performance of water-alkali electrolyzers. Here, we demonstrate a dramatic enhancement of HER kinetics in base by judiciously hybridizing vertical MoS2 sheets with another earth-abundant material, layered double hydroxide (LDH). The resultant MoS2/NiCo-LDH hybrid exhibits an extremely low HER overpotential of 78 mV at 10 mA/cm2 and a low Tafel slope of 76.6 mV/dec in 1 M KOH solution. At the current density of 20 mA/cm2 or even higher, the MoS2/NiCo-LDH composite can operate without degradation for 48 hr. This work not only brought forth a cost-effective and robust electrocatalyst, but more generally opened up new vistas for developing high-performance electrocatalysts in unfavorable media recalcitrant to conventional catalyst design.