Design and Excellent HER Performance of a Novel 3D Mo–Doped Ni 3 S 2 /Ni Foam Composite

Abstract A new method was applied to facilitate Mo doping in Ni 3 S 2 , which successfully fabricated Mo‐doped Ni 3 S 2 /Ni foam composite. The results of X‐ray diffraction (XRD) and X‐ray photoelectron spectroscopy (XPS) manifest that Mo element was triumphantly introduced into Ni 3 S 2 . The Mo‐doped Ni 3 S 2 /Ni foam composite possesses three‐dimensional (3D) hierarchical structure with column type characterized by scanning electron microscopy (SEM). The diameter of the column is ∼300 nm. Each of these columns is made up of many nanopetals. The hydrogen evolution reaction (HER) test results exhibit that the products have outstanding HER performance. The Tafel slope of the optimal Mo‐doped Ni 3 S 2 /Ni foam composite is 131.7 mV dec −1 . The overpotentials are 97.1 mV and 392.1 mV at the current density of 10 mA cm −2 and 100 mA cm −2 , respectively. Moreover, the products show good stability.