Hydrogen Evolution Reaction Property of Molybdenum Disulfide/Nickel Phosphide Hybrids in Alkaline Solution

Abstract

The hydrogen evolution reaction (HER) property of molybdenum disulfide (MoS2) is undesirable because of the insufficient active edge sites and the poor conductivity. To enhance HER performance of MoS2, nickel phosphide (Ni2P) was combined with this catalyst and three MoS2/Ni2P hybrids (38 wt % Ni2P addition for MoS2/Ni2P-38, 50 wt % Ni2P addition for MoS2/Ni2P-50, and 58 wt % Ni2P addition for MoS2/Ni2P-58) were fabricated via a hydrothermal synthesis process. Morphologies, crystallinities, chemical components, specific surface areas, and HER properties of the fabricated MoS2/Ni2P samples in an alkaline electrolyte were characterized and tested. In addition, the insight into the HER properties of as-prepared catalysts were revealed by the density functional theory (DFT) calculation. Additionally, the stabilities of pure MoS2, Ni2P, and MoS2/Ni2P-50 samples were evaluated. The results show that the addition of Ni2P can enhance the HER property of the MoS2 catalyst. Although HER properties of the above-mentioned three MoS2/Ni2P hybrids are inferior to that of pure Ni2P, they are much higher than that of MoS2. Among as-prepared three hybrids, MoS2/Ni2P-50 exhibits the best HER performance, which may be due to its uniform morphology, large specific surface area, and excellent stability. The MoS2/Ni2P-50 hybrid shows a high cathodic current density (70 mA/cm2 at −0.48 V), small Tafel slope (~58 mV/decade), and a low charge transfer resistance (0.83 kΩ·cm2).

Keywords

• hydrogen evolution reaction
• molybdenum disulfide
• nickel phosphide
• hydrothermal synthesis
• density functional theory
• alkaline electrolyte