Fabrication of a 3D self-supporting Ni-P/Ni2P/CC composite and its robust hydrogen evolution reaction properties in alkaline solution

Developing robust and low-cost hydrogen evolution reaction (HER) catalysts in alkaline media still faces enormous challenges. Herein, a novel 3D self-supporting nickel phosphorus/nickel phosphide/carbon cloth (Ni-P/Ni2P/CC) composite was fabricated by using combined processes of nickel phosphorus electrodeposition, hydrothermal synthesis and low temperature phosphorization techniques, for the loading of Ni-P nanoparticles and Ni2P nanosheets onto the surface of CC. The characteristics of the fabricated Ni-P/Ni2P/CC composite in terms of crystallinity, surface morphology and chemical components were analyzed, and the HER properties in alkaline solution were evaluated. The synthesized Ni-P/Ni2P/CC composite exhibits preeminent HER activity; among the three composites, the Ni-P/Ni2P/CC-2 sample displays the highest catalytic activity with a low overpotential of 95 mV to afford a current density of 10 mA cm(-2). Moreover, this composite exhibits outstanding electrochemical stability (without apparent loss in HER activity after 2000 cyclic voltammetry cycles). For this self-supporting Ni-P/Ni2P/CC composite, the deposited Ni-P nanoparticles fill the sites not occupied by Ni2P nanosheets on the surface of CC, and thus the effect of the synergy between Ni-P and Ni2P on the enhancement in HER performance is verified. The fabricated Ni-P/Ni2P/CC composite deserves to be considered as an appealing candidate for HER application in alkaline solution.