Electric field tuned MoS₂/metal interface for hydrogen evolution catalyst from first-principles investigations

Area of Science:

• Materials Science
• Surface Science
• Computational Chemistry

Background:

• Interfacial properties of catalysts are key for designing efficient catalysts.
• Molybdenum disulfide (MoS₂) is a promising electro-catalyst for hydrogen production, with field effects enhancing its activity.
• The atomic-level mechanisms governing MoS₂ electro-catalysis remain poorly understood.

Purpose of the Study:

• To investigate the impact of external electric fields on the interfacial electronic structure of MoS₂/Au systems.
• To elucidate the atomic mechanism behind electric field-enhanced catalysis in MoS₂-based systems.
• To explore the tunability of hydrogen adsorption on MoS₂/Au under electric fields.

Main Methods:

• Density Functional Theory (DFT) based first-principles calculations.
• Utilizing the MoS₂/Au system as a model to study interfacial electronic properties.
• Simulating the effects of an applied external electric field on the catalyst-substrate interface.

Main Results:

• An applied electric field effectively modulates charge transfer between MoS₂ and Au, despite the absence of covalent bonding.
• The electric field can tune the Schottky barrier type from n-type to p-type and reduce its height, facilitating charge injection.
• Hydrogen adsorption energy on MoS₂/Au is controllable within a wide range by modest electric fields.

Conclusions:

• External electric fields offer a powerful tool to control interfacial electronic structures and catalytic activity in MoS₂/Au systems.
• The findings provide fundamental insights into the mechanism of field-effect catalysis, aiding the design of improved catalysts.
• This work paves the way for understanding and controlling catalysts with defects, vacancies, or nanostructures in practical applications.