Visible Light Photodegradation of Glyphosate and Methylene Blue Using Defect-Modified Graphitic Carbon Nitride Decorated with Ag/TiO₂

Abstract

The presence of various organic pollutants in surface and ground waters has raised serious environmental threats across the world. In the present work, the solvothermal process was applied to prepare a ternary composite of barium defect-modified graphitic carbon nitride (DM g. C3N4) decorated with silver and titanium oxide for the photocatalytic removal of dyes and pesticides in visible light. Methylene blue (MB) and glyphosate were targeted pollutants. Enhanced structural defects in the carbon nitride framework were reported and characterized by using FTIR, SEM, EDS, XRD, and UV/Visible spectroscopy. Various analytical techniques confirmed the proficient coating of titanium oxide and silver on the surface of DM g. C3N4. The photocatalytic efficiency of synthesized materials for the degradation of persistent organic pollutants and various parameters such as the effect of pH, catalytic dosage, the concentration of pollutant, reusability of the catalyst, etc., were estimated by using UV/Visible spectroscopy. Batch experiments were performed to estimate the degradation efficiency and other parameters by using an absorption study. A scavenger analysis confirmed hydroxyl radicals as the main reactive species for the degradation of various pollutants. The results confirm that the ternary composite of barium DM g. C3N4 showed an increased response in the visible region, greater stability, and excellent photocatalytic efficiency toward the degradation of the organic compounds. The results confirm that the maximum degradation of the said organic pollutants occurs in 105 min.

Keywords

• defect-modified graphitic carbon nitride
• glyphosate
• methylene blue
• photocatalytic degradation