Double-Confined Ultrafine Cobalt Clusters for Efficient Peroxide Activation.

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Peroxide activation is crucial for advanced oxidation processes (AOPs) but faces challenges in catalyst development.
• Designing highly active and stable catalysts for efficient pollutant degradation remains a significant hurdle.

Purpose of the Study:

• To develop a novel catalyst with enhanced activity and durability for peroxide activation in AOPs.
• To investigate the structure-activity relationship of confined metal clusters in catalytic pollutant degradation.

Main Methods:

• Facile synthesis of ultrafine cobalt (Co) clusters confined in N-doped carbon dots decorated mesoporous silica nanospheres (Co/NC@mSiO2) using a double-confinement strategy.
• Evaluation of catalytic performance for organic pollutant removal using peroxymonosulfate (PMS) under various pH conditions.
• Density functional theory (DFT) calculations to elucidate the catalytic mechanism and electronic structure.

Main Results:

• Co/NC@mSiO2 exhibited unprecedented catalytic activity and durability compared to unconfined catalysts.
• The catalyst demonstrated effective pollutant degradation across a wide pH range (2-11) with minimal cobalt ion leaching.
• DFT calculations and experimental results confirmed strong PMS adsorption, efficient charge transfer, and optimized electronic structures of Co clusters, facilitating HO• and SO4•− radical generation.

Conclusions:

• The double-confined Co/NC@mSiO2 catalyst represents a fundamental breakthrough in designing highly efficient and stable catalysts for peroxide activation.
• The synergistic effect between confined Co clusters, N-doped carbon dots, and mesoporous silica enhances catalytic performance by optimizing electronic properties and facilitating radical generation.
• This work provides valuable insights into the design principles for advanced catalysts in environmental remediation.