g-C3N4 Based Photocatalyst for the Efficient Photodegradation of Toxic Methyl Orange Dye: Recent Modifications and Future Perspectives

Industrial effluents containing dyes are the dominant pollutants, making the drinking water unfit. Among the dyes, methylene orange (MO) dye is mutagenic, carcinogenic and toxic to aquatic organisms. Therefore, its removal from water bodies through effective and economical approach is gaining increased attention in the last decades. Photocatalytic degradation has the ability to convert economically complex dye molecules into non-toxic and smaller species via redox reactions, by using photocatalysts. g-C3N4 is a metal-free n-type semiconductor, typical nonmetallic and non-toxici polymeric photocatalyst. It widely used in photocatalytic materials, due to its easy and simple synthesis, fascinating electronic band structure, high stability and abundant availability. As a photocatalyst, its major drawbacks are its limited efficiency in separating photo-excited electron-hole pairs, high separated charge recombination, low specific surface area, and low absorption coefficient. In this review, we report the recent modification strategies adopted for g-C3N4 for the efficient photodegradation of MO dye. The different modification approaches, such as nanocomposites and heterojunctions, as well as doping and defect introductions, are briefly discussed. The mechanism of the photodegradation of MO dye by g-C3N4 and future perspectives are discussed. This review paper will predict strategies for the fabrication of an efficient g-C3N4-based photocatalyst for the photodegradation of MO dye.

Automated summary

Industrial effluents containing dyes, especially methylene orange (MO) dye, are major pollutants in water bodies, posing risks to human health and aquatic organisms. Photocatalytic degradation using g-C3N4 as a metal-free semiconductor photocatalyst has emerged as an effective and economical approach for removing MO dye from water. Different modification strategies, such as nanocomposites, heterojunctions, doping, and defect introductions, have been adopted to enhance the efficiency of g-C3N4 in photodegradation. This review discusses these modification approaches, the mechanism of photodegradation, and provides future perspectives for the development of efficient g-C3N4-based photocatalysts.