Ni-Activated Transition Metal Carbides for Efficient Hydrogen Evolution in Acidic and Alkaline Solutions

Transition metal carbides (TMCs) feature high catalytic activity and superior stability for the hydrogen evolution reaction (HER). However, their platinum-like HER catalytic performance is heavily hindered, due to their strong interaction with hydrogen. Herein, Ni activation of TMCs (M = V, Fe, Cr, and Mo) is proposed through introducing adsorbed nickel atoms on the TMC surface (Ni/TMC). In both acidic and alkaline solutions, a sharp decrease of both overpotentials and Tafel slopes of the Ni/TMC catalysts for HER is achieved. At 10 mA cm(-2), the overpotentials of the Ni/vanadium carbide (VC) and Ni/Fe3C catalysts are 128 and 93 mV in 1mKOH, 111 and 112 mV in 0.5mH(2)SO(4), respectively. Even at 150 mA cm(-2), they exhibit the overpotentials of as low as 270 and 291 mV, respectively. In the alkaline solutions, the performance of these Ni/TMC catalysts is even superior to a Pt/C catalyst. As confirmed from density functional theory calculations and X-ray absorption fine structure analysis, such adsorbed Ni atoms effectively optimize the d-electron structure and improve HER performance. As a versatile strategy, this work provides a universal route to activate TMCs for highly efficient HER in different media.