N-doped carbon nanoweb-supported Ni/NiO heterostructure as hybrid catalysts for hydrogen evolution reaction in an alkaline phase

Abstract

The design of the cost-effective, efficient, and durable electrocatalysts for hydrogen evolution reaction (HER) is of great importance in the field of clean and renewable energies. In this study, Ni/NiO nanocomposite supported on N-doped carbon nanoweb (Ni/NiO/NCW) hybrid materials are proposed as an efficient electrocatalyst for HER in alkaline media. A series of Ni/NiO/NCW hybrid catalysts were prepared via polymerization of polypyrrole (PPy) in the presence of a surfactant, followed by incipient wetness impregnation and heat treatment techniques. The resulting Ni/NiO/NCW hybrid catalysts exhibit an excellent electrocatalytic properties with a lower overpotential of 105.3 mV (vs RHE) at 10 mA cm(-2), a smaller value of Tafel slope (55.2 mV dec(-1)) and almost 100% Faradaic efficiency. It also shows good stability in performance attenuation during continuous cyclic voltammetry sweeps for 1000 cycles. Its excellent electrocatalytic performance for alkaline hydrogen evolution reaction can be attributed to the synergistic effect associated with the morphological benefit of 3D N-doped carbon nanoweb and Ni/NiO heterostructure with the optimal ratio of Ni to NiO. (C) 2020 Elsevier B.V. All rights reserved.