Defect-rich MoS2 nanosheets vertically grown on graphene-protected Ni foams for high efficient electrocatalytic hydrogen evolution

Defect-rich MoS2 nanosheets are vertically grown on graphene-protected Ni foam by a facial hydrothermal route. The vertically aligned MoS2 nanosheets with defects such as cracks, amorphousness and oxygen-incorporated disorders endow these as-synthesized catalysts with rich active sites, high conductivity and good stability. The graphene deposited on Ni foam increases its stability in acid. The optimized catalyst exhibits high activity for hydrogen evolution with a quite low overpotential of 140 mV at 10 mA cm−2, a small Tafel slope of 42 mV decade−1, and a large exchange current density of 63 μA/cm2, as well as excellent stability. This performance is superior to most of its analogue MoS2 and many transition metal sulfides. This work will broaden the vision to improve the activity of self-supported electrocatalysts by carefully designing the anchored catalysts.