Two-Dimensional Tetragonal Transition Metal Chalcogenides for High Performance Oxygen Evolution and Reduction: A DFT...

Area of Science:

• Materials Science
• Electrochemistry
• Computational Chemistry

Background:

• High-performance bifunctional catalysts are crucial for electrochemical water splitting and fuel cells.
• Oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts are key components in these energy conversion systems.

Purpose of the Study:

• To investigate 2D tetragonal transition metal chalcogenide (TMX) monolayers as potential bifunctional electrocatalysts for OER and ORR.
• To evaluate the catalytic activity and selectivity of various TMX monolayers using computational methods.

Main Methods:

• Density functional theory (DFT) calculations were employed to study a series of 2D tetragonal TMX monolayers.
• A descriptor, Gmax, was introduced to assess the OER performance.
• The bifunctional index (BI) was used to rank the overall catalytic activity for bifunctional OER/ORR applications.

Main Results:

• Several TMX monolayers, including CdS, CdSe, FeSe, NiSe, and NiTe, exhibited Gmax values below 1.0 V, indicating superior OER activity.
• NiSe demonstrated excellent ORR performance with an overpotential (ηORR) of 0.53 V.
• The catalytic activity ranking based on the bifunctional index (BI) was determined as NiSe > NiTe > FeSe > CdS > CdSe > NiS > TiSe > ZnTe.

Conclusions:

• 2D tetragonal TMX monolayers show significant potential as efficient bifunctional electrocatalysts for OER/ORR.
• NiSe and NiTe are identified as particularly promising candidates for further experimental investigation.
• The findings provide valuable insights for designing next-generation 2D materials for electrocatalysis.