The sample was subjected to centrifugatiin at 9500 rpm for 10 min before being subjected to analysis through a UV spectro
Attached is the screen shot for the same with the bottom most spectra for blank sample and top most after 30 min degradation
Probably the increase in absorption that you noticed is caused by the generation of by-products, due to the reaction of bisphenol A with i.e. hydroxyl radicals or other oxidising species. It means that the by-products show a larger absorbance than bisphenol A, because of a different extinction coefficient.
I recommend the following:
-Before starting the photodegradation process, you must keep the reaction medium in the dark for at least half an hour.
-Did you add an external source of oxygen? for example, hydrogen peroxide? If so, the radicals that absorb the radiation can be generated in the wavelength range you are using.
-You may be forming intermediate complexes that absorb radiation. That's why you see this effect ...
What catalyst are you using? You might think about changing the catalyst and reaction conditions ...
Sometimes this has happened to us and we have been able to correct it with some experimental changes (concentrations, oxygen source or catalyst).
I recommend the following:
-Before starting the photodegradation process, you must keep the reaction medium in the dark for at least half an hour.
-Did you add an external source of oxygen? for example, hydrogen peroxide? If so, the radicals that absorb the radiation can be generated in the wavelength range you are using.
-You may be forming intermediate complexes that absorb radiation. That's why you see this effect ...
What catalyst are you using? You might think about changing the catalyst and reaction conditions ...
Sometimes this has happened to us and we have been able to correct it with some experimental changes (concentrations, oxygen source or catalyst).
Sir Francisco Manuel Marquez
The reaction mixture was subjected to a dark reaction and then exposed to a light source.
-No external sacrificial reagents were added to the reaction mixture
-Catalyst being used is a composite heterojunction material synthesised by me in our lab
-I even tried degrading BPA by reducing the concentration to 5 ppm from 20 pmm but the same condition persists ( i hope analysisng the Intermediates through other spectroscopic techniques shall shed some light of the overall process)
Thankyou for Your suggestions :-)
The achievement of the adsorption-desorption equilibrium between the organic pollutant and the photocatalyst is very important. Have a look on this study as an example.
Article Development of hierarchically porous LaVO4 for efficient vis...
The incomplete oxidation of Bisphenol A produces metabolites: quinone derivatives, carboxylic acids whose absorption maxima are at the beginning of the UV spectrum.
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