Synthesis of CaWO4 as a Photocatalyst for Degradation of Methylene Blue and Carmine under Ultraviolet Light Irradiation
Round 1
Reviewer 1 Report
Since the author closely analyzes and reports the photocatalytic performance of CaWO4, the result itself is considered sufficiently valuable. However, the composition of the experimental report level lowers the overall quality of the draft and does not sound scientifically at all. Most importantly, many parts are added as Supporting Information, but SI data is not attached. Therefore, a reexamination is strongly requested.
Author Response
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Reviewer 2 Report
Reviewer Comments to Author
After going through the article, I noticed that the authors are doing good efforts but it can be better for discussing the problem and scientific content properly to get published in the current journal.
They have synthesized CaWO4 as a photocatalyst. HOWEVER, I recommend its acceptance with major mandatory revision as per following comments
1. Introduction seems to be very week and need to be improved drastically with proper justification of current work as the titled material is well know and large number of articles are already exist in literature
2. Abstract should be revised.
3. Have the authors tried the degradation with CR/MO dyes ??.
4. Results and discussion needs to be done with more proper justifications and also a Table for degradation efficiency should be included for same as well different materials and compare the current outcomes.
https://doi.org/10.1016/j.jenvman.2022.117134, https://doi.org/10.1016/j.physb.2023.414654, https://www.mdpi.com/2073-4344/13/2/240#, https://doi.org/10.1080/10667857.2022.2107821
5. Conclusion should be rewritten with more specific details ?
6. Update all references accordingly.
Author Response
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Reviewer 3 Report
File attached
Comments for author File: Comments.pdf
Author Response
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Round 2
Reviewer 1 Report
The authors deserve a lot of credit for his efforts in making a revised paper that is an improvement over the original. However, there are still many critical issues that need to be pointed out, so a major revision is required.
1. About the performance of the catalyst: The author decomposed 0.1 g of MR, CR with 1 g of catalyst. This means that the reactivity is low. It is unclear whether the author compared the performance per g in table 1. Also, there must be other examples of CaWO4, and comparisons between same species (including doping) are very important.
2. The authors claim that this work will lead to new ideas, but it is unclear where the originality of this work lies. The synthesis of CaWO4 is not new, nor is the use of scavengers to analyze mechanisms. As the authors claim. Is there good performance without doping and without additional oxidants, and if so, what is the cause?
3. it is very questionable whether this is appropriate for this journal. There is little content from a process perspective and the synthesis method is not new. Or is there something new in synthesis process?
4. Show the energy graph for either direct or indirect band gap (figure 1b).
5. The BET measurement condition is missing. DFT method was used?
6. Figure 1b: Why did the authors measure with UV-DRS rather than conventional UV-vis, and is the pattern shown in figure 1b typical of CaWO4?
7. Figure 1: Figure and caption don't match, h,I,j and what elements.
8. Regarding the zeta potential value: It is a common pattern for oxides to vary linearly with pH. However, the pattern shown in SI is difficult to understand. The author should double-check the reproducibility and accuracy of this data as this is a very important part of drawing results and conclusions.
9. Sections 3.2.4 and 3.3.4 are for supporting information.
10. Restate the purpose of CRs more specifically at the beginning of Section 3.3.1.
11. Regarding stability in CR reactions: Usually, the catalyst's deactivation is indicated by a gradual decrease in reactivity. However, in this experiment, a sharp decrease occurred in the 4th cycle. Please comment on this phenomenon.
12. Line 66: doubled words
13. Line 112: Indicate the role of CTAB, etc.
14. Do the same for the legend in Figure 3, and match the order of the captions.
Author Response
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Reviewer 2 Report
Can be accepted
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Reviewer 3 Report
The authors revised the manuscript as per suggestions and recommend it for publication.
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