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Turkish Journal of Chemistry

Abstract

Industrial wastewater from sectors such as textiles, printing, and pharmaceuticals contains harmful pollutants, including nonbiodegradable dyes, which pose significant challenges for environmental safety. Neutral red, a cationic dye commonly found in wastewater, obstructs photosynthesis in aquatic ecosystems and carries potential toxicity. Traditional methods of dye removal often prove ineffective due to the chemical stability of these compounds. In this study, oxygen-doped graphitic carbon nitride (O-doped g-C3N4) was synthesized as an innovative photocatalyst for the degradation of neutral red dye under visible light. The material was synthesized through a sustainable process involving the calcination of urea, dicyandiamide, and oxalic acid, and its characteristics were evaluated using various techniques, including XRD, FT-IR, UV-Vis spectroscopy, and SEM. Photocatalytic degradation of neutral red was analysed using a custom photoreactor under visible light. The results demonstrated that O-doped g-C3N4 exhibited enhanced photocatalytic efficiency compared to pure g-C3N4, reducing the recombination of electron-hole pairs and effectively degrading the dye. Adsorption kinetics followed a pseudo-2nd-order model, while adsorption isotherms suggested that the Langmuir model best described the adsorption process, indicating monolayer adsorption. The maximum adsorption capacity of O-doped g-C3N4 for neutral red was 9.643 mg g-1, surpassing pure g-C3N4. The photocatalytic performance of OCN-UD was assessed under visible light, revealing a significant degradation efficiency of 86% for neutral red after 60 minutes, compared to 51% for pure g-C3N4. Kinetic studies indicated that the adsorption of neutral red onto OCN-UD primarily followed a pseudo-2nd-order model, demonstrating chemical adsorption processes. The synergistic effects of adsorption and photocatalysis were evident, as the initial adsorption phase concentrated dye molecules near active sites, facilitating efficient photocatalytic degradation through reactive oxygen species generation. This study highlights the potential of O-doped g-C3N4 as an efficient, eco-friendly solution for the treatment of dye-laden wastewater.

Author ORCID Identifier

MUCHAMMAD TAMYIZ: 0000-0001-6647-9286

DOI

10.55730/1300-0527.3724

Keywords

Adsorption kinetics, neutral red dye removal, oxygen-doped g-C3N4, photocatalytic degradation, visible light photocatalysis

First Page

228

Last Page

240

Publisher

Scientific and Technological Research Council of Türkiye (TUBITAK)

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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