Unleashing the Power of Oxygen-Doped Graphitic Carbon Nitride: Enhancing Neutral Red Removal Efficiency

Textile industry wastewater often contains persistent pollutants like neutral red dye, which are challenging to break down and harmful to ecosystems. This study introduces oxygen-doped graphitic carbon nitride (O-g-C3N4) as a photocatalyst to degrade neutral red dye under visible light. Synthesized using a single-step calcination of urea, dicyandiamide, and oxalic acid, O- g-C3N4 was tested for its efficiency in neutral red removal through adsorption and photocatalytic degradation, both in light and dark conditions. Results showed that O- g-C3N4 quickly adsorbed the dye, reaching equilibrium in 30 minutes and achieving a maximum adsorption capacity of 1.86 mg g-1, surpassing bulk g-C3N4. Kinetic analysis indicated that adsorption followed a pseudo-second-order model, suggesting chemisorption as the primary mechanism. Under visible light, O- g-C3N4’s photocatalytic degradation reached 86% neutral red removal, compared to 51% with bulk g-C3N4, largely due to improved light absorption and reduced electron-hole recombination. Degradation of neutral red followed pseudo-first-order kinetics, with O- g-C3N4’s reaction rate three times greater than bulk g-C3N4. The Sips isotherm best fit the adsorption data, confirming heterogeneous active sites and multilayer adsorption. These findings highlight O- g-C3N4’s potential for environmental remediation.