Anchoring Iron Single Atoms into Ordered Mesoporous C₃N₄@N-C Hybrids for Efficient Peroxymonosulfate Activation:...

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Single-atom catalysts on carbon nitride show promise for peroxymonosulfate (PMS) activation in pollutant removal.
• Challenges exist in creating ordered mesoporous structures to maximize surface area and reactive species utilization.

Purpose of the Study:

• To synthesize a single-atom Fe catalyst confined in a mesoporous C3N4@N-C hybrid support (Fe-C3N4@N-C) using a solvent-free nanocasting method.
• To investigate its performance in activating PMS for bisphenol A (BPA) degradation.

Main Methods:

• Solvent-free nanocasting strategy for synthesizing Fe-C3N4@N-C.
• Characterization of catalyst structure, surface area, and pore volume.
• Bisphenol A degradation experiments using PMS activation.
• Mechanistic studies including DFT calculations.

Main Results:

• The Fe-C3N4@N-C catalyst featured atomically dispersed Fe-N4 sites within an ordered mesoporous structure (surface area ~462 m²/g, pore volume 0.46 cm³/g).
• Achieved >99% BPA removal in 20 min and ~77% mineralization in 60 min, with degradation rate constants significantly higher than controls.
• Demonstrated a nonradical pathway dominated by singlet oxygen and electron transfer, showing excellent stability, pH adaptability, and anti-interference.

Conclusions:

• The Fe-C3N4@N-C catalyst effectively activates PMS for efficient BPA degradation.
• The ordered mesoporous structure and Fe-N4 sites are crucial for high catalytic activity and stability.
• This catalyst presents a promising solution for advanced oxidation processes in water treatment.