The properties ,uses of Rhodamine B? what is the environmental problem? why to go for degradation? why the impartant of visible light?
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Rhodamine B is a Basic dye and it has two molecular forms of Cationic and Zwitterionic form. Cationic dyes are considered as toxic colorants and can cause harmful effects such as allergic dermatitis, skin irritation, mutations and cancer. In the UV–vis spectra of RhB solution, the absorbance of dye solution at 553 nm (n → π* transition of C=N, C=O groups) is used to monitor the decolonization level.
They also have Xanthene rings and the aromatic compounds constitute an important source of environmental pollution reaching the atmosphere and ground waters because there are widely used as intermediates in the production of pesticides, synthetic polymers, dyes, etc. In other words they are water pollutant and the removal of color from waste effluents becomes environmentally important because even a small quantity of dye in water can be toxic and highly visible.
RhB decomposition can occur in by two mechanism :
•Photocatalytic process → Degradation of the conjugated structure [rings] (no peak shift)
•Photosensitized Process → Degradation via the N-de-ethylation (blue shift)
the first one is mostly observed under UV light and the former one under the visible light. its means that RhB may directly break down to its photo-degraded end products like CO2, NO3 or NOx or via stepwise N-de-ethylation. Bandgap excitation of semiconductor particles can initiate the oxidation and reduction processes of the adsorbed substrate. Alternatively The photosensitization process , requires the adsorbed colored molecule to inject an electron from its excited state into conduction band of semiconductor particles and itself become a positively charged radical, which undergoes further transformation to give stable products.
I give you some keywords so you can search the details :
Rhodamine B is a Basic dye and it has two molecular forms of Cationic and Zwitterionic form. Cationic dyes are considered as toxic colorants and can cause harmful effects such as allergic dermatitis, skin irritation, mutations and cancer. In the UV–vis spectra of RhB solution, the absorbance of dye solution at 553 nm (n → π* transition of C=N, C=O groups) is used to monitor the decolonization level.
They also have Xanthene rings and the aromatic compounds constitute an important source of environmental pollution reaching the atmosphere and ground waters because there are widely used as intermediates in the production of pesticides, synthetic polymers, dyes, etc. In other words they are water pollutant and the removal of color from waste effluents becomes environmentally important because even a small quantity of dye in water can be toxic and highly visible.
RhB decomposition can occur in by two mechanism :
•Photocatalytic process → Degradation of the conjugated structure [rings] (no peak shift)
•Photosensitized Process → Degradation via the N-de-ethylation (blue shift)
the first one is mostly observed under UV light and the former one under the visible light. its means that RhB may directly break down to its photo-degraded end products like CO2, NO3 or NOx or via stepwise N-de-ethylation. Bandgap excitation of semiconductor particles can initiate the oxidation and reduction processes of the adsorbed substrate. Alternatively The photosensitization process , requires the adsorbed colored molecule to inject an electron from its excited state into conduction band of semiconductor particles and itself become a positively charged radical, which undergoes further transformation to give stable products.
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