The high QY is possibly due to the existence of nitrogen-containing functional groups, which are generally excellent
auxochromes and greatly enhance photoluminescence.
The attached chromophores and
auxochromes are considered to be the main source of azo dye color, the explanation of the decoloration process is that the radiolysis product of dimethylformamide by 60Co I3-irradiated is the following [9]:
Auxochromes groups (COOH and OH) present in the structure of these pigments causes them to absorb light within the visible energy range from sunlight, in a less efficient way, when compared to commercial dyes, but presenting a lower cost and adequate deposition technique, making their use viable.
The band appears at 211 nm shows the presence of substituted carbonyl or carboxyl system accompanied by
auxochromes [18].
(2000) conducted some studies on the decolourization of acidic dye effluent (Sandolan Yellow--an azo group in association with two aromatic systems and
auxochromes) with applied ultrasound, electro-oxidation and the combined process.