Amorphous MoS2 Decorated Ni3 S2 with a Core-shell Structure of Urchin-Like on Nickel-Foam Efficient Hydrogen Evolution in Acidic and Alkaline Media.

The large-scale commercialization of the hydrogen evolution reaction (HER) necessitates the development of cost-effective and highly efficient electrocatalysts. Although transition metal sulfides, such as MoS2 and Ni3 S2 , hold great potential in the field of HER, their catalytic performance has been unsatisfactory due to incomplete exposure of active sites and poor electrical conductivity. In this work, via a simple hydrothermal strategy, amorphous MoS2 nanoshells in the form of urchin-like MoS2 -Ni3 S2 core-shell heterogeneous structure is realized and in situ loaded on nickel foam (A-MoS2 -Ni3 S2 -NF). In particular, XPS analysis results show that the coupling of amorphous MoS2 and Ni3 S2 makes the electrode surface exhibit electron-abundant property, which will have a positive impact on HER catalytic activity. In addition, the fully exposed active site of amorphous MoS2 is another crucial factor contributing to its high catalytic performance of A-MoS2 -Ni3 S2 -NF electrode. In particular, at a current density of 10 mA cm⁻2 , the overpotential of electrode is 95 mV (1.0 m KOH) and 145 mV (0.5 m H2 SO4 ). This work highlights the importance of amorphous MoS2 and MoS2 -Ni3 S2 of sea-urchin core-shell structure in optimizing HER performance, which provides an important reference for HER research.