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

Abstract

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.

Fabrication of graphitic carbon nitride synthesized via pyrolysis for environmental remediation: a detailed experimental analysis with different parametric optimizations

“…The band edge values of the valence and conduction bands of g-C 3 N 4 can be determined by the following equations: E VB = χ − E e + 0.5 E g E CB = E VB − E g where χ is the absolute electronegativity, E e is the energy of free electrons, and E VB and E CB are the valence and conduction band edges of g-C 3 N 4 . The absolute electronegativity χ of g-C 3 N 4 was taken as 4.73 from earlier reported values, 49 while E e was taken as 4.5 eV, 49 and the band gap energy was taken from the band gap value calculated from the UV-vis absorption spectrum given in Fig. 5(a) and (b).…”

Development of the Sb4O5Cl2@NbSe2 Composite: The Impact of 2H-NbSe2 Nanoparticles on Sb4O5Cl2 and Their Application for the Removal of Cr(VI)/Fe(III) and Methyl Orange from Wastewater

“…More importantly, the heavy metal ions iron and chromium, as well as methyl orange, pose a significant long-term threat to water, soil, and living organisms due to their ease of transfer and bioaccumulation. The excessive presence of these contaminants in drinking water can cause serious damage to human beings and aquatic animals through carcinogenic and mutagenic effects. − Iron is commonly found in groundwater and may exist in a soluble form as Fe­(II) or Fe­(OH) + ions or as Fe­(III) ions forming complexes with colloidal minerals or organic matter, which increase the growth of microbes in water. Chromium, on the other hand, occurs in two stable oxidation states in aqueous solutions, namely, +3 and +6, of which Cr­(III) is less toxic and has limited hydroxide solubility compared to Cr­(VI), which is the most toxic oxidation state of chromium and possesses high solubility and mobility in aqueous systems.…”

Carbon Dots from Tire Waste for the Photodegradation of Methyl Orange Dye, Antimicrobial Activity, and Molecular Docking Study

“…[4] Its widespread use in textiles, leather, and paper industries, to color materials like fabrics, paper, and plastics raises environmental concerns. [5] Azo dyes including MO, can persist in water bodies, leading to water pollution, reduced light penetration in water, hampering photosynthesis for aquatic plants, and affecting the aquatic ecosystem. [6,7] Additionally, MO, have been classified as potentially harmful to human health, emphasizing the need for their effective.…”

“…Methyl orange is an azo dye often employed as an indicator in various chemical reactions, exhibits a characteristic transition from orange‐red (acidic) to a yellow (basic) [4] . Its widespread use in textiles, leather, and paper industries, to color materials like fabrics, paper, and plastics raises environmental concerns [5] . Azo dyes including MO, can persist in water bodies, leading to water pollution, reduced light penetration in water, hampering photosynthesis for aquatic plants, and affecting the aquatic ecosystem [6,7] .…”