Cobalt Phosphorous Trisulfide as a High-Performance Electrocatalyst for the Oxygen Evolution Reaction.

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Two-dimensional (2D) layered materials are crucial for developing efficient electrocatalysts in energy conversion.
• Metal phosphochalcogenides (MPX3) show potential for water splitting, but oxygen evolution reaction (OER) catalysis remains challenging due to activity and stability limitations.

Purpose of the Study:

• To investigate the OER catalysis of M2P2X6 (MPX3) materials.
• To identify superior MPX3 catalysts for efficient and stable water splitting.

Main Methods:

• Synthesized and screened a series of M2P2X6 materials (M = Mn, Fe, Co, Zn, Cd; X = S, Se).
• Employed liquid-phase exfoliation to enhance catalyst properties.
• Conducted electrochemical studies to evaluate OER performance.
• Utilized quantum chemical modeling to understand catalytic mechanisms.

Main Results:

• CoPS3 exhibited the best OER performance among the tested MPX3 materials, comparable to IrO2 and RuO2.
• Liquid-phase exfoliation of CoPS3 significantly improved OER activity and stability.
• Exfoliated CoPS3 achieved a low overpotential of 234 mV at 10 mA/cm2 and maintained performance at 100 mA/cm2.
• Quantum chemical models indicated edge-site moieties on CoPS3 are key to low overpotentials via a two-site mechanism.

Conclusions:

• CoPS3 is a highly promising electrocatalyst for the oxygen evolution reaction in water splitting.
• Exfoliation enhances CoPS3's catalytic properties, offering a viable strategy for catalyst improvement.
• The findings suggest CoPS3 can be an efficient and stable material for anodic water-splitting reactions.