I am working on the photocatalytic degradation of MB dye. It consists of a quartz double jacket with an arrangement for UV lamps of different power ratings (50W, 150W and 250W). I studied the photo degradation of MB dye using undoped ZnO and Samarium doped ZnO (1%,3%and 5%) as photocatalysts. But, photo degradation efficiency (PE) came out to be 47%, 75%, 56%, 78% for undoped ZnO and 1%,3%and 5%Samarium doped ZnO, respectively in 4 hours. I optimised the parameters for different pH, dye conc, photocatalyst concentration. What can be done to improve the PE and that too in lesser timing so as to make it efficient for practical apps? Could there be any problem in apparatus?Why is there shifting of peak towards the the left with degradation?
Dear Sukriti Khera,
What is the distance between the lamp and you solution? You need a correct irradiance to get the degradation. How your reactor is designed? if your reactor are too thick, you may have reduction of the light flux (even if quartz is transparent to UV).
You can also increase your specific surface of you ZnO.
Concerning the shift of your spectra, do you have an increase of the temperature during you experiment? It may explain it.
Regards,
Emile
Thanks for the reply.
The distance between the lamp and the solution is 10 cm. The thickness is being taken care of. There might be an error of +-2 temperature as it is being maintained by adding ice.
Dear Sukriti Khera,
Have you checked the band gap and PL spectra of said materials,that should be able to answer variations in your result.
And for shift of uv-vis spectra towards left is due to degradation of MB and formation of intermediates with new lamda max,so when superimposed leads to the shift.
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