Redefining water purification: gC₃N₄-CLDH's electrochemical SMX eradication

Area of Science:

• Environmental Chemistry
• Materials Science
• Water Treatment Technologies

Background:

• Pharmaceutical compounds in water pose global environmental and health risks.
• Efficient technologies are needed to remove emerging contaminants like sulfamethoxazole (SMX).
• Novel composite materials offer potential solutions for advanced oxidation processes.

Purpose of the Study:

• To synthesize and characterize a novel graphitic carbon nitride-calcined (Fe-Ca) layered double hydroxide (gC3N4-CLDH) composite.
• To evaluate the electrochemical degradation efficiency of SMX using the gC3N4-CLDH composite.
• To investigate the degradation mechanism and applicability in different water matrices.

Main Methods:

• Synthesis and characterization of gC3N4-CLDH using SEM, XRD, FTIR, and XPS.
• Electrochemical degradation experiments to assess SMX and TOC removal.
• Identification of reactive oxygen species and evaluation of regeneration and pH effects.

Main Results:

• The gC3N4-CLDH composite exhibited well-defined structures and morphology.
• Over 98% SMX removal and 75% TOC removal were achieved under optimized conditions.
• Superoxide and hydroxyl radicals were identified as key reactive species, with excellent performance across various pH levels and good regeneration capability (7 cycles).

Conclusions:

• The gC3N4-CLDH composite is a highly effective and sustainable material for electrochemical SMX degradation.
• While natural organic matter like humic acid can slow degradation, the composite shows efficacy in real water samples (groundwater, industrial wastewater).
• This research provides a strong basis for applying gC3N4-CLDH in real-world water treatment scenarios.