Facile electrochemical synthesis of Ni(OH)2/MoSx catalyst on oxidized carbon fiber for efficient alkaline hydrogen evolution reaction

Abstract

The efficient electrochemical hydrogen evolution reaction in alkaline media through the use of earth-abundant catalysts has received significant attention, as it is a crucial means for sustainable H2 production. Here, we present a facile synthesis approach for Ni(OH)2/MoSx (MoSx: amorphous molybdenum sulfide) catalyst on oxidized carbon fiber support. Carbon fibers are first oxidized by a hydrothermal treatment in a concentrated HNO3 solution, while Ni(OH)2 and MoSx films are consecutively deposited onto the substrate through simple electro-deposition methods from their plating solutions. Benefiting from the hydrophilicity of the oxidized carbon fiber, the abundant electrochemically reactive sites and the synergistic effect between Ni(OH)2 and MoSx, this hybrid catalyst shows a low HER onset potential of 80 mV at 1 mA/cm2, an overpotential of 180 mV at 10 mA/cm2 and a remarkable stability of at least 35 working hours at a H2-evolving current density of 10 mA/cm2 without any obvious overpotential changes.