Hydrogen can be the potential substitute energy carrier for fuel while electrolysis water with hydrogen evolution reaction (HER) is an efficient way to produce hydrogen. Highly active and robust electrocatalysts composed by earth abundant elements are required. Herein, nickel-copper-phosphorus (Ni-Cu-P) electrocatalysts are designed and synthesized by a facile one-step electrodeposition method. A unique pine-needle-like dendrite nanotube morphology of Ni-Cu-P electrocatalyst can be synthesized when copper content changed and impressive HER activity obtained in alkaline and acidic media. Briefly, the overpotential reaches 120 mV in 1 M KOH and 150 mV in 0.5 M H2SO4 at the current density of 10 mA cm-2, with the corresponding Tafel slope reaching 69 mV dec-1. The results are close to that of commercial Pt/C catalysts (37 mV in 1 M KOH). Furthermore, the density functional theory calculations also demonstrate that P-incorporated Ni-Cu, Cu-incorporated Ni-P, and Ni-incorporated Cu-P have the optimized hydrogen adsorption free energy (Δ GH*) of -0.066, -0.157, and -0.003 eV, respectively, which are more suitable than those of Ni-Cu, Ni-P, and Cu-P, respectively. The Ni-incorporated Cu-P even has a much smaller Δ GH* of -0.003 than that of Pt (∼-0.09 eV). We believe that our study will provide a new strategy to design non-noble metal alloy materials for practical applications in catalysis and energy fields.
Keywords: Ni−Cu−P; electrocatalysts; first-principles calculations; hydrogen evolution reaction.