Review Reports

Round 1

Reviewer 1 Report

In this work, the authors have developed a real-time UV/VIS spectroscopy to detect photocatalytic reactions in real time. However, the experimental results obtained so far are limited and lack some actual evidence. Before it can be published, I think some questions should be clearly discussed and a major revision is also necessary.

1. In order to further illustrate the degradation process, the intermediates with different degradation times need to be detected by liquid chromatography.

2. When the amount of catalyst is increased, the catalytic degradation rate should be better, but the effect of sample D is inferior to that of sample C. The author needs to further explain this phenomenon.

3. Dye degradation is too fast to accurately obtain the corresponding mechanism through real-time UV/VIS spectroscopy, the author needs to increase the dye concentration to obtain more information of mechanism.

4. The authors need to give the mineralization rates of different samples to further explain the degree of benzene ring cracking.

5. According to the current results, although this technique can obtain some useful information, it can not accurately infer the mechanism of dye degradation. The author needs to add some applications that can obtain the specific mechanism.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, Woo et al., developed a real-time UV/VIS spectroscopy device to detect photocatalytic degradtion of a synthetic dye (MB) in real time. The set up was caliberated and proved to be effective to yield spectroscopic insight into the process of photocatlaytic degradation with a high resolution up to 20 milisec. Currently, most of the photocatalytic researches focus on the synthesis of novel photocatalyts while little studies pay attenttion to photocatalytic degradation  process using real time technique. This study therefore is of significance to advance the knowledge regarding real time technique to investigate photocatlaytic process. Therefore, I recommend the acceptance of the manuscript after minor revision.

1. The title "Photocatlytic degaradtion” is not accurate, the author only invesitigate the degradation of MB, while this set up may not be applicable to other organic molecules that are not chromophores.

2. The author should also consider the dection limit of the MB. Very high concentration of MB may have inner filter effect.

3. Is it possible to further process the data? For example, the 1st or 2nd derivative of the absorbance curves may yield more inforamtion. 

4. The author only use lab-prepared dye as the degradation target. In real practice, the water matrix may contain components like ions, other organic matters, etc. The authors are recommended to strengthen the discussion or provide their viewpoint regarding this aspect when using their setup.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors responded to each of our questions, and I agree to accept this manuscript.in this journal.