Almost 100 % Peroxymonosulfate Conversion to Singlet Oxygen on Single-Atom CoN₂₊₂ Sites

Area of Science:

• Environmental Chemistry
• Materials Science
• Catalysis

Background:

• Single-atom CoN4 sites are efficient for peroxymonosulfate (PMS) activation.
• The precise identification of active sites and singlet oxygen generation mechanisms in PMS activation remains unclear.

Purpose of the Study:

• To regulate reactive oxygen species generation using atomically dispersed cobalt on nitrogen-doped carbon.
• To elucidate the active sites and singlet oxygen generation mechanism during PMS activation.

Main Methods:

• Experimental characterization of atomically dispersed cobalt on nitrogen-doped carbon.
• Density Functional Theory (DFT) calculations.
• Investigation of PMS activation pathways and reactive oxygen species (ROS) generation.

Main Results:

• CoN2+2 was identified as the dominant active site.
• Singlet oxygen was the predominant ROS, accounting for 98.89% of generation.
• PMS oxidation occurred via a non-radical pathway with simultaneous singlet oxygen generation.
• Generated singlet oxygen efficiently degraded organic pollutants over a wide pH range.

Conclusions:

• Atomically dispersed cobalt on nitrogen-doped carbon provides a platform for controlled ROS generation.
• The CoN2+2 active site facilitates non-radical PMS oxidation and singlet oxygen production.
• This strategy offers an efficient method for organic pollutant degradation in wastewater treatment.