Boosting Hydrogen Evolution Reaction of Nickel Sulfides by Introducing Nonmetallic Dopants

Although introducing heteroatoms into Ni-based compounds is an efficient way to promote HER activity, the absence of rational design strategies, especially for nonmetallic dopants, impedes the development of electrocatalysts. Herein, the role of nonmetallic dopants and alkaline HER performance of nonmetal atom doped Ni3S2 (X-Ni3S2, X = B, C, N, 0, P) electrocatalysts are investigated by combining density functional theory and experiment methods. Results illustrate that heteroatoms in X-Ni3S2 can alter surface electronic states, change active sites, boost H2O dissociation kinetics and optimize H ad-desorption ability. In particular, O-Ni3S2 and C-Ni3S2 exhibit superior HER activity, which only require very low overpotentials of 68.4 and 85.5 mV, respectively, to deliver a geometrical current density of 10 mA cm(-2). Simultaneously, a nice stability of over 50 h has been achieved. This can be attributed to the strong C/O-Ni interaction, which induces favorable charge transfer and, therefore, facilitates the formation of specific optimal active sites for H2O dissociation and H ad-desorption.