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

Fan Yang,Jun He,Jiayun Yan,Siyue Huo,Ning Kang,Laizhou Song,Xiuli Wang

doi:10.3390/met8050359

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).

Highlights

With growing concerns about environmental pollution and energy crises resulting from overconsumption of coal and fossil fuels, the exploitation of renewable clean energies, such as solar energy, wind energy, hydraulic power, biological energy, fuel cell, and hydrogen energy come to the forefront [1,2,3]
It should be noted that the diffraction peak of (002) plane of MoS2 is undetected
Morphologies, crystallinities, and chemical components of pure MoS2, Ni2 P, three MoS2/Ni2P hybrids obtained via a hydrothermal synthesis process were characterized

Summary

Introduction

With growing concerns about environmental pollution and energy crises resulting from overconsumption of coal and fossil fuels, the exploitation of renewable clean energies, such as solar energy, wind energy, hydraulic power, biological energy, fuel cell, and hydrogen energy come to the forefront [1,2,3]. Among the clean energies mentioned above, hydrogen energy is attracting ever-growing attention due to the convenient production and effective cost [4,5]. The well-known platinum and platinum-based alloys show the best electrocatalytic performance for HER [10,11,12,13]. Their high-cost and scarcity impede their wide applications in practice [14,15,16]. To facilitate HER application, it is urgent to develop low-cost alternatives with Earth-abundant and cost-effective features to replace the noble metals [17,18]. Various non-noble materials including transition metal sulfides [19], selenides [20], oxides [21], carbides [22], and nitrides [23], Metals 2018, 8, 359; doi:10.3390/met8050359 www.mdpi.com/journal/metals

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