Azo dyes are one of the most widely used dyes in the world since they are utilized in numerous industries: textiles, printing, food, etc. However, these dyes also represent an environmental threat as about 10-15% of the dyes are released into environment after textile manufacturing. This poses an issue as the dyes absorb light, thus disturbing the aqueous life. Additionally, the degradation products of these dyes (aromatic amines) are often toxic even if the dye itself is not. As such, determination of water purification techniques for the removal of these harmful by-products has become a priority in recent work. Photocatalysis has emerged as one of the most promising methods for this purpose, as it can be carried out under ambient conditions, it is inexpensive, and can be supported on a variety of suitable, environment-friendly materials. However, there is still much to learn about the properties and degradation mechanism of different azo dyes in order to successfully apply this technique. This work utilizes Density Functional Theory (DFT) methods to calculate properties of a variety of aryl azo naphthol dyes, including bond lengths, HOMO/LUMO orbitals, and IR, NMR, and UV spectra, and to explore their degradation mechanisms via photocatalysis. Furthermore, the substitution of different electron-withdrawing and electron-donating groups are to be investigated and compared to determine the effect on the degradation process.

Theoretical investigation of the properties and radical degradation mechanism of aryl azo naphthol dyes

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.