P-doped CNTs encapsulated nickel hybrids with flower-like structure as efficient catalysts for hydrogen evolution reaction

Abstract

Electrochemical water splitting attracted an increasing attention as a promising approach to produce high-purity hydrogen. Both the design and synthesis of low-cost and high-performance catalysts for hydrogen evolution reaction (HER) remain challenging. Herein, an in-situ growth of carbon nanotubes encapsulated Ni particles on nickel foam is described. This catalyst is synthesized via a one-step chemical vapor deposition (CVD) at different temperatures followed by P-doping treatment (P-doped Ni@CNTs/NF). The corresponding physicochemical and electrochemical results illustrate that the P-doped Ni@CNTs/NF prepared at 600 °C with flower-like structure exhibits excellent activity and stability for HER in acidic electrolytes. In 0.5 M H 2 SO 4 aqueous solution, the sample shows a small overpotential value of −135.2 mV to achieve a current density of −10 mA cm −2 , which also displays acceptable long-term stability for lasting 20 h. This work provides a facile approach to prepare a cost-effective catalyst with high efficiency and might promote further study of the transition metal catalysts for hydrogen evolution in acid environments. © 2018 Elsevier Ltd