Preparation of Zn5Mo2O11·5H2O@Sulfonated Graphene by Template Method and Its Anticorrosion Mechanism in Polyurethane Coatings
Round 1
Reviewer 1 Report
Title- Preparation of Sheet Zn5Mo2O11·5H2O@Sulfonated Graphene and its Anticorrosion Performance in Waterborne Polyurethane Coatings
Authors- Z. Zhao, K. Chen, S. Wen, J. Wang, J. Xu, S. Wang, W. Li, J. Song
Manuscript Id- Coatings-1958107
In this manuscript, the authors have synthesized Zn5Mo2O11·5H2O@Sulfonated Graphene coatings on carbon steel via template method, and investigated their corrosion protection performance. Characterization facilities adopted in this manuscript are sufficient to provide the discussion. However, after a careful review with interest, the reviewer has below comments that need to be incorporated extensively into the manuscript. This manuscript also falls short on scientific writing and the English language to meet the standards of MDPI Coatings. The authors are advised to revise the manuscript extensively, and hence recommend a major revision.
Below are some comments/suggestions for the authors;
[1] The authors should consider rewriting of introduction section. I suggest referring to the articles enclosed in Annexure 1, which will help to improve the current understanding of authors about waterborne coatings and enrich the introduction part. Authors are encouraged to refer to those articles.
[2] The authors should also clearly define the novelty of their work. The present introductory section its missing.
[3] How the template method is advantageous over other synthesis methods? Authors should also discuss those aspects briefly. Because, each synthesis method has its own pros and cons, and corrosion protection performance is greatly influenced by process parameters.
[4] Furthermore, how the authors have optimized synthesis parameters? Please explain.
[5] The size and resolution of the Figures could be better. At present its difficult to read.
[6] Which type of peak fitting is adopted in XPS analysis? And why? Needs more clarification.
[7] What was the size of the carbon steel substrate? I hope the authors have used the correct area for corrosion protection performance calculations. Since the authors only mentioned 1 cm x 1 cm, if it’s a plate then how about the other (or back) surface? Authors should either seal the back surface with resin or consider doubling the surface area. Please have a look and refer to the articles from Annexure 1.
[8] The scale markers in SEM images are too small to read.
[9] A quick question: How about the porosity in these coatings? What are its consequences on the corrosion performance of SZMO@SG?
[10] Any specific reason why 3%SZMO@SG exhibits better corrosion protection performance? Needs more clarification
In my opinion;
[1] The work is interesting and authentic. However, manuscripts fall short from the discussion point of view. Authors are also advised to polish their manuscript for the English language. Language is not scientific.
[2] The discussion in the manuscript is speculative. Authors are advised to look into the literature thoroughly and enrich the discussion part.
[3] Many unclear facts are presented in the manuscript. However, I advise the authors to revise the manuscript extensively, and hence recommend a major revision.
Comments for author File: 
Comments.pdf
Author Response
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Author Response File: 
Author Response.docx
Reviewer 2 Report
This article contains good and valuable information about coatings. After correcting the manuscript based on the comments, I will announce my opinion regarding the acceptance or rejection of the article. Consider all the comments below and highlight the changes.
1 – The quality of the language of the article should be reviewed.
2- Do not use long sentences in the abstract. The investigated parameters should be briefly stated in the abstract. In the abstract, state what tests were used and what results were obtained. Extra sentences should be deleted. Before using abbreviations, these words must be spelled out in full.
3- In the introduction, the relationship between metallurgical parameters, microstructural changes and corrosion properties has not been investigated. Introduction is not acceptable in its current format. Use the following articles to complete this section:
- https://doi.org/10.1007/s00339-019-2854-8 , - https://doi.org/10.1039/C9TA03995C , - Characterization of bioactivity behavior and corrosion responses of hydroxyapatite-ZnO nanostructured coating deposited on NiTi shape memory alloy, Ceramics International, Vol. 44 (17), 2018, 21395-21405.
4- coating parameters should be presented in a table.
5- All formulas used must be specified from which reference they are derived.
6- State the standard used for corrosion testing.
6- What was the value of the open circuit potential? How much time was needed for the corrosion potential to reach equilibrium?
7- The results presented in Tables 2 and 3 should be reported along with the standard deviation.
8- The relationship between microstructure (grain size) and corrosion rate has not been investigated.
Author Response
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Author Response File: Author Response.docx
Reviewer 3 Report
Zhao et al. examine the preparation of sheet Zn5Mo2O11·5H2O@sulfonated graphene and its anticorrosion performance in waterborne polyurethane coatings. The article is written nicely, explaining all the aspects related to the study. It will help researchers who are working in the same field. I recommend its acceptance after a minor revision followed by the editorial correction.
1. Title should be modified as it does not give the scientific meaning of the research.
2. Abstract should contain key findings of the work, please add it.
3. In the introduction section, add a few new published works; https://doi.org/10.1016/j.molliq.2022.118867; https://doi.org/10.1016/j.molliq.2022.119384.
4. The conclusion can be improved.
5. Authors can explain more about the EIS and PDP.
6. Please check the entire manuscript and remove grammatical errors.
Author Response
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Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Title- Preparation of Sheet Zn5Mo2O11·5H2O@Sulfonated Graphene and its Anticorrosion Performance in Waterborne Polyurethane Coatings
Authors- Z. Zhao, K. Chen, S. Wen, J. Wang, J. Xu, S. Wang, W. Li, J. Song
Manuscript Id- Coatings-1958107R1
The reviewer had a detailed look at the revised version of the manuscript. The manuscript has been substantially improved and is almost ready for publication. However, below are the issues that need to be amended in the manuscript on a priority basis before its final publication. I request authors to consider these issues positively.
[1] Although the discussion part is significantly improved, it would be nice if the authors try to explain EIS results in more detail. It would be also appreciated to shed some light on the porosity measurement. They can take the help of the articles enclosed below for enriching their discussion part. These are the essential articles, however not cited in the previous version of the manuscript;
https://doi.org/10.1016/j.apsusc.2006.06.030
10.1515/eetech-2018-0006
https://doi.org/10.1080/02670844.2016.1214385
https://doi.org/10.1515/corrrev-2018-0094
[2] I also suggest authors to maintain uniformity in units. For ex., the standard unit for current density is mA/cm2 and not the µA/cm2. In such cases, authors need to do some simple calculations in the data points based on an area exposed during the corrosion testing and modify the data. Furthermore, it would be nice to indicate Y-Axis of Fig. 9 that measured potential is with respect to what? Either vs. OCP or vs. SCE or vs. any other standard electrode. Please look into the above publications and how they have described the EIS and polarization figures. This is mandatory before the final acceptance of the paper.
[3] Again in Fig. 9, is it current density or current or log (current density)? Please verify.
In my opinion;
[1] The manuscript has been improved significantly. Still, there are some grammatical errors in the manuscript, which can be easily fixed during proofreading stage. I recommend its acceptance and congratulate the authors. However, the above comments need to be amended mandatorily before the final publication of the manuscript.
Comments for author File: Comments.pdf
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 2 Report
I recommend "Publish As Is".
Author Response
Dear reviewer，
We thank you very much for the comments and suggestions. The suggestions are valuable and helpful for revising and improving our manuscript. We thank you for the consideration of acceptation again.
Best regards.
