Defects Enhance the Electrocatalytic Hydrogen Evolution Properties of MoS₂ -based Materials

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Molybdenum disulfide (MoS₂) is a promising alternative to noble metals for hydrogen evolution reaction (HER) catalysis due to its abundance and cost-effectiveness.
• However, MoS₂ suffers from limited active sites, an inert basal plane, and poor electrical conductivity, hindering its catalytic efficiency.
• Defect engineering offers a viable approach to overcome these limitations and enhance HER performance.

Purpose of the Study:

• This review focuses on defect engineering strategies to improve the electrocatalytic activity of MoS₂ for HER.
• It explores methods to activate the basal plane, increase the number of active edge sites, and enhance conductivity.
• The study aims to provide a comprehensive overview of defect-related research in MoS₂-based HER catalysts.

Main Methods:

• The review discusses the characterization techniques used to identify and analyze defects in MoS₂.
• It covers various preparation methods for introducing controlled defects, such as sulfur vacancies and edge modifications.
• The role of defective conductive carbon supports in improving catalyst conductivity is also examined.

Main Results:

• Defects, particularly sulfur vacancies, can tune the electronic structure of MoS₂, optimizing hydrogen adsorption free energy for improved HER activity.
• Introducing edge defects significantly increases the density of active sites, leading to enhanced catalytic performance.
• Defective conductive carbon supports effectively improve the overall conductivity of MoS₂-based electrocatalysts.

Conclusions:

• Defect engineering is a powerful strategy to enhance the electrocatalytic performance of MoS₂ for HER.
• Tailoring defects allows for simultaneous improvement of intrinsic activity, active site density, and conductivity.
• Further research into defect control and characterization will unlock the full potential of MoS₂ as a sustainable HER catalyst.