Synergistic Ag/g–C3N4 H2O2 System for Photocatalytic Degradation of Azo Dyes

TL;DR

This paper presents a new photocatalytic system using Ag/g-C3N4 and H2O2 to efficiently degrade azo dyes under visible light.

Contribution

The study introduces a synergistic Ag/g–C3N4–H2O2 system with enhanced photocatalytic efficiency for dye degradation.

Findings

g-C3N4 loaded with 6% Ag achieved 100% degradation of methyl orange and methylene blue within 70 and 80 minutes.

Hydroxyl and superoxide radicals were identified as the main active species in the degradation process.

The photocatalyst showed good reusability and stability in the synergistic system.

Abstract

Graphitic carbon nitride (g-C3N4), known for being nontoxic, highly stable, and environmentally friendly, is extensively used in photocatalytic degradation technologies. Silver nanoparticles effectively capture the photogenerated electrons in g-C3N4, enhancing the photocatalytic efficiency. This study primarily focused on synthesizing graphitic carbon nitride via thermal polymerization and depositing noble metal silver onto g-C3N4 through photoreduction. Methyl orange (MO) and methylene blue (MB) were targeted as the pollutants in the photocatalytic experiments under visible light in conjunction with a H2O2 system. The characteristics peaks, structure, and morphology were analyzed using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). g-C3N4 loaded with 6% Ag exhibited superior photocatalytic performance; the photocatalytic fraction of the degraded materials of the MO and MB solutions reached 100% within 70 and 80 min, respectively, upon adding 1 mL and 2 mL of H2O2. ·OH and ·O2− were the primary active free radicals in the dye degradation process within the synergistic system. Stability tests also demonstrated that the photocatalyst maintained good reusability under the synergistic system.

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