ZnO-Modified g-C₃N₄: A Potential Photocatalyst for Environmental Application

Area of Science:

• Materials Science
• Environmental Science
• Photocatalysis

Background:

• Semiconducting materials offer promising solutions for solar energy-driven wastewater treatment.
• Developing efficient photocatalysts is crucial for effective pollutant degradation.
• Graphitic carbon nitride (g-C3N4) and zinc oxide (ZnO) are key materials in photocatalysis.

Purpose of the Study:

• To synthesize and characterize a novel composite photocatalyst of g-C3N4 and ZnO (GCN-ZnO).
• To evaluate the enhanced adsorption and photocatalytic activity of the GCN-ZnO composite for wastewater remediation.
• To investigate the stability and potential of the composite for organic pollutant abatement.

Main Methods:

• One-step thermal polymerization of urea and zinc carbonate basic dihydrate to create the GCN-ZnO composite.
• Characterization of the composite's morphology, surface area, and optical properties.
• Assessment of adsorption and photocatalytic performance under visible light irradiation, including stability tests.

Main Results:

• The GCN-ZnO0.4 sample exhibited an increased surface area (116 m2 g-1) and enhanced visible light absorption compared to pure g-C3N4.
• The composite showed a reduced band gap and significantly improved adsorption and photocatalytic activity, with reaction rates up to three times higher than pure g-C3N4.
• The enhanced performance was attributed to improved photogenerated charge carrier separation due to heterojunction formation between g-C3N4 and ZnO.
• The GCN-ZnO0.4 sample demonstrated good stability over four cyclic runs.

Conclusions:

• The GCN-ZnO composite is a superior photocatalyst for wastewater remediation compared to pure g-C3N4.
• The heterojunction structure effectively enhances charge carrier separation, leading to improved photocatalytic efficiency.
• The material shows significant potential for the abatement of organic wastewater pollutants using solar energy.