Graphdiyne-Stabilized Cobalt Oxyhydroxide Quantum Dots for Efficient Nitrate-to-Ammonia Electrocatalysis

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Electrocatalytic nitrate reduction reaction (NtRR) is a sustainable alternative to the Haber-Bosch process for ammonia synthesis.
• Challenges include sluggish kinetics and low selectivity due to competing reactions.

Purpose of the Study:

• To develop a high-performance electrocatalyst for NtRR.
• To investigate the role of graphdiyne in modifying cobalt oxyhydroxide.

Main Methods:

• In situ transformation of cobalt oxyhydroxide (CoOOH) nanosheets into quantum dots (QDs) on graphdiyne (GDY).
• Experimental characterization and theoretical calculations to understand interfacial charge transfer and active sites.
• Electrochemical testing of the CoOOH@GDY catalyst for NtRR.

Main Results:

• The CoOOH@GDY catalyst demonstrated excellent NtRR performance.
• Achieved 98.01% Faradaic efficiency for ammonia production.
• Obtained a high NH3 yield rate of 1644 µmol h⁻¹ cm⁻² with high stability.

Conclusions:

• Graphdiyne-mediated interface engineering is effective for designing advanced electrocatalysts.
• The CoOOH@GDY catalyst shows significant potential for efficient and sustainable ammonia synthesis.