Optimized g-C₃N₄/TiO₂ composites for visible-light-driven sonophotocatalysis in norfloxacin removal

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Antibiotic pollution in water poses a significant environmental and health risk.
• Conventional water treatment methods struggle to effectively remove persistent organic pollutants like norfloxacin.
• Developing efficient and sustainable catalytic systems is crucial for advanced oxidation processes.

Purpose of the Study:

• To synthesize and characterize g-C3N4/TiO2 composites for enhanced sonophotocatalytic degradation of norfloxacin.
• To investigate the structural, morphological, and electronic properties of the synthesized composites.
• To elucidate the mechanism behind the enhanced catalytic activity.

Main Methods:

• Synthesis of g-C3N4/TiO2 composites.
• Structural, morphological, and spectroscopic characterization (e.g., XRD, SEM, TEM, XPS).
• Sonophotocatalytic degradation experiments under visible light and ultrasonic irradiation.
• Liquid chromatography-mass spectrometry (LC-MS) for degradation pathway analysis.

Main Results:

• Successful formation of g-C3N4/TiO2 composites with strong interfacial interactions and effective charge separation.
• Superior norfloxacin degradation efficiency (rate constant of 5.91 × 10^-2 s^-1) compared to individual components and traditional photocatalysis.
• Identification of S-scheme heterojunctions and piezoelectric fields contributing to enhanced activity.
• Demonstration of mineralization into non-toxic byproducts via LC-MS analysis.

Conclusions:

• g-C3N4/TiO2 composites exhibit excellent sonophotocatalytic activity for norfloxacin degradation.
• The S-scheme heterojunction and piezoelectric effects are key to the enhanced performance.
• These composites represent a promising sustainable catalyst for wastewater treatment and antibiotic removal.