Arrayed Cobalt Phosphide Electrocatalyst Achieves Low Energy Consumption and Persistent H₂ Liberation from Anodic...

Area of Science:

• Electrochemistry
• Materials Science
• Clean Energy Production

Background:

• Electrochemical water splitting is key for clean hydrogen (H₂) production.
• Challenges include efficient H₂ recovery and managing energy consumption in electrolysis apparatus.

Purpose of the Study:

• To develop a membrane-free pathway for H₂ purification using a novel electrocatalyst.
• To optimize electrochemical apparatus for efficient H₂ evolution and recovery.

Main Methods:

• Utilized cobalt phosphide nanoarrays (Co₂P/CoP NAs) as a charge mediator in alkaline water electrolysis.
• Investigated the hierarchical array structure and electronic configuration of Co₂P/CoP NAs.
• Performed theoretical calculations to understand the catalytic mechanism for hydrogen evolution reaction (HER).

Main Results:

• Achieved time-separated H₂ and O₂ evolution, enabling membrane-free H₂ purification.
• Co₂P/CoP NAs demonstrated high efficiency as bifunctional electrocatalysts for charge storage and HER.
• Maintained H₂ evolution at 10 mA cm^-2 for 1500 s with a low average voltage of 1.38 V.
• Coupling with ammonia oxidation required only 0.21 V to sustain current for 1188 s.

Conclusions:

• The Co₂P/CoP NAs facilitate efficient HER through optimized hydrogen adsorption and water dissociation.
• The membrane-free architecture offers a low-cost strategy for hydrogen purification technology.
• This approach significantly reduces energy requirements for hydrogen production.