Effective Electrocatalytic Hydrogen Evolution in Neutral Medium Based on 2D MoP/MoS₂ Heterostructure Nanosheets.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• The hydrogen evolution reaction (HER) is crucial for clean energy production.
• Neutral media offer advantages over acidic/basic conditions for HER, but require catalysts with specific properties.
• Developing efficient catalysts for neutral HER with good conductivity, porosity, and active sites remains a challenge.

Purpose of the Study:

• To design and synthesize a novel 2D MoP/MoS2 heterostructure catalyst for efficient hydrogen evolution reaction (HER) in neutral media.
• To investigate the catalytic performance and understand the underlying mechanisms of the MoP/MoS2 heterostructure for HER.
• To evaluate the catalyst's potential in overall water splitting applications.

Main Methods:

• Synthesis of 2D MoP/MoS2 heterostructure nanosheets supported on carbon cloth (CC).
• Electrochemical characterization of the catalyst for HER performance in neutral, alkaline, and acidic media.
• X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations to analyze material properties and active sites.
• Fabrication and testing of overall water splitting cells using the MoP/MoS2 cathode and NiFe-LDH anode.

Main Results:

• The MoP/MoS2 heterostructure catalyst achieved a low overpotential of 96 mV for a current density of 10 mA cm-2 in neutral media, significantly outperforming bare MoS2 (199 mV).
• The catalyst demonstrated excellent HER activity in alkaline (54 mV) and acidic (69 mV) media.
• XPS and DFT calculations confirmed the presence of abundant active sites at the MoP/MoS2 heterointerface, good conductivity, and favorable mass transfer properties.
• Overall water splitting cells coupled with NiFe-LDH anodes achieved current densities of 10 mA cm-2 at 1.51 V (1 M KOH) and 1.98 V (1 M PBS), driven by a solar panel.

Conclusions:

• The 2D MoP/MoS2 heterostructure nanosheets represent a highly efficient and stable catalyst for HER across a wide pH range.
• The synergistic effects at the MoP/MoS2 heterointerface are key to the enhanced catalytic activity.
• This catalyst shows significant promise for practical applications in electrocatalysis and solar-driven water splitting for hydrogen production.