Highly dispersive NiCo2S4 nanoparticles anchored on nitrogen-doped carbon nanofibers for efficient hydrogen evolution reaction

To solve the energy crisis problem, many efforts have been devoted to develop clean and sustainable alternatives to fossil fuels. Among varieties of pathways to obtain clean energy, electrochemical water splitting is a promising approach. Herein, we had successfully synthesized the NiCo2S4@porous nitrogen-doped carbon nanofibers (NiCo2S4@NCNF) nanocomposite via three successive steps consisted of in-situ oxidative polymerization, calcination, and solvothermal sulfuration reaction processes. The effect of controlled molar ratios to electrocatalytic performance was studied in detail. The optimized NiCo2S4@NCNF nanocomposite exhibits superior electrocatalytic activity for hydrogen evolution reaction with a small overpotential of 117 mV to drive a current density of 10 mA cm(-2). More importantly, it exhibits similar electrocatalytic activity to the initial state even after successive cyclic voltammetry scan for 3000 cycles, indicating its excellent long-term stability. The superior electrochemical performance is attributed to the developed three-dimensional (3D) network nanostructure derived from bacterial cellulose nanofibers, the highly conductive porous nitrogen-doped carbon nanofibers, and the synergistic effect between metal Ni and Co of NiCo2S4. This study permits a new pathway to design efficient electrocatalysts based on eco-friendly materials for the production of clean hydrogen energy. (C) 2019 Elsevier Inc. All rights reserved.