Upcycling Water Pollutants Into Long-Chain Polymers via Synergistic Interfacial Dechlorination and Organic Radical...

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• High-entropy oxides (HEOs) exhibit unique electronic properties due to lattice distortion and multimetal synergy.
• Developing efficient catalysts for pollutant removal and upcycling is crucial for environmental sustainability.

Purpose of the Study:

• To synthesize and evaluate nitrogen-doped carbon-encapsulated HEOs (HEO@NC) as catalysts for efficient pollutant removal and upcycling.
• To investigate the catalytic mechanism of HEO@NC in activating periodate for selective oxidative polymerization of phenolic contaminants.

Main Methods:

• In situ carbothermal reduction for synthesizing HEO@NC catalysts.
• Experimental analyses including density functional theory (DFT) to elucidate catalytic mechanisms.
• Performance evaluation in pollutant removal and wastewater treatment under various conditions.

Main Results:

• HEO@NC demonstrated significantly enhanced periodate activation compared to metal-free catalysts, achieving 449.2% utilization efficiency.
• The catalyst selectively converted phenolic contaminants into polymeric products, even under extreme pH and ionic interference.
• Synergistic effects of HEO components (Co/Ni, Pt, Bi/Pb) were identified, facilitating dechlorination-coupled polymerization and sustained 4-chlorophenol removal.
• HEO@NC maintained >95% efficiency with minimal metal leaching during 20-day treatment of real industrial wastewater.

Conclusions:

• HEO@NC catalysts offer a promising pathway for efficient and sustainable remediation of industrial wastewater.
• The catalyst's ability to activate periodate and enable selective oxidative polymerization presents a low-chemical-consumption approach for pollutant upcycling.