Optically Transparent TiO2 and ZnO Photocatalytic Thin Films via Salicylate-Based Sol Formulations
Round 1
Reviewer 1 Report
In this research, TiO2 and ZnO thin films are fabricated and characterized by various techniques, and simulation. Also, photocatalytic performance of the system is examined using methylene blue degradation. The results obtained are interesting in the field; but I have some comments mentioned below:
1. Novelty of research is not clear. Please add a paragraph to the Introduction, to clearly describe the novelty of research.
2. According to Figure 7, the coatings are generally amorphous; and therefore, the presence of TiO2 or ZnO can not be directly concluded. Authors are invited to perform additional characterizations such as Raman spectroscopy to confirm the formation of these phases.
3. UV-Vis spectrum of MB and its absorption peak needs to be explained.
4. Photocatalytic performances need to be compared with alternative materials recently used as the photocatalyst for the degradation of MB. For example: https://doi.org/10.1016/j.mssp.2023.107798; https://doi.org/10.1016/j.jallcom.2021.161201; https://doi.org/10.1016/j.jwpe.2023.103903; https://doi.org/10.1016/j.ceramint.2023.02.089
5. Mechanisms involved in the degradation of MB should be discussed.
6. How about the degradation of alternative dyes?
English edit can improve quality of the manuscript.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In the manuscript optically transparent TiO2 and ZnO photocatalytic thin films were obtained via salicylate-based sol formulations. The work was carried out on up-to-date equipment, which allows one provide complex study of the obtained films. The methods are enough described. ATR-FTIR & DFT investigation of the TiO2 and ZnO salicylate sols are very important. The manuscript can be accepted for publication after major revision and correction of comments.
1. The abstract should be rewritten by summarizing the problem, the method, the results, and the conclusions. Don't use the common observations and suggestions.
2. The abbreviations used must be deciphered. We recommend do not use abbreviations in the abstract (FTIR, UV and others).
3. Why is the synthesis of TiO2 sol carried out at room temperature, and ZnO – using a little heating?
4. Lines 134 and 174 – you need to specify the type of glass substrates (quartz, calcium-sodium) that were used as a substrate. If non-quartz glasses were used, it is necessary to explain how the transmission spectra were taken, because calcium-sodium glasses also absorb, was this taken into account?
5. Why is methylene blue chosen as a model pollutant? MB decomposes under UV irradiation even in the absence of a photocatalyst. Did the authors take this into account in the experiment?
6. Figure 8b. How can the authors explain the sharp rise near 550 nm, and then the decline for the composition of Ti:15 (green curve)? A similar question, how can authors explain the sharp decline and then rise for the red curve (Ti:10)?
7. It is necessary to carefully check and edit the text. For example, 2.2.1 is a technical error, the section title is not written in italics, similarly for some other sections.
8. The English in the manuscript can be improved
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Authors have revised the article and addressed the technical issue.
There are a large number of errors and language issues. Language polish is required.
Reviewer 2 Report
In the manuscript optically transparent TiO2 and ZnO photocatalytic thin films were obtained via salicylate-based sol formulations. The work was carried out on up-to-date equipment, which allows one provide complex study of the obtained films. The methods are enough described. ATR-FTIR & DFT investigation of the TiO2 and ZnO salicylate sols are very important. The manuscript can be accepted for publication
