Heterogeneous core-shell Co₂(PS₃)@Co₂P nanowires with accelerated surface reconstruction for efficient...

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Designing durable and active catalysts for seawater oxidation is crucial but challenging.
• Electrochemical reconstruction of pre-catalysts is key to achieving desired catalytic properties.

Purpose of the Study:

• To design and synthesize a novel core-shell pre-catalyst for alkaline seawater oxidation.
• To investigate the electrochemical reconstruction process and its impact on catalytic performance.
• To understand the structure-composition-activity relationship for efficient oxygen evolution reaction (OER) catalysts.

Main Methods:

• Epitaxial growth of amorphous cobalt phosphide (Co2P) on crystalline cobalt phosphorous trichalcogenide (Co2(PS3)) to form CoPS.
• Utilizing various characterization techniques to analyze the catalyst structure and composition.
• Employing theoretical simulations to understand the mechanism of action.

Main Results:

• The CoPS pre-catalyst rapidly reconstructs into an active CoPS-R catalyst with amorphous-crystalline nanowire structure.
• In situ derived oxyanions (PO4^2-, SO3^2-, SO4^2-) on CoOOH surface optimize the OER intermediates' chemisorption.
• CoPS-R exhibits low overpotentials (357 mV at 200 mA cm^-2, 402 mV at 500 mA cm^-2) and over 500 h durability in alkaline natural seawater.

Conclusions:

• The novel CoPS pre-catalyst effectively reconstructs into a highly active and durable OER catalyst (CoPS-R) for seawater electrolysis.
• In situ generated oxyanions play a critical role in enhancing catalytic performance by tuning electronic structure and optimizing intermediate binding.
• This work provides a new strategy for developing efficient and robust OER catalysts by leveraging pre-catalyst design and controlled electrochemical reconstruction.