Synergistic Effect of Benincasa hispida Peel Extract and KI on the Corrosion Inhibition of Mild Steel in HCl

Round 1

Reviewer 1 Report

The article, titled 'Synergistic Effect of Benincasa hispida Peel Extract and KI on the Corrosion Inhibition of Mild Steel in HCl,' is well-written and presents an intriguing idea of utilizing plant extract to prevent steel corrosion. I commend the authors on their presentation of this paper.

However, I do have a few minor questions regarding the durability of the proposed solution.

Firstly, I would like to inquire if the adhesion of the peel extract on the mild steel was evaluated using any quantitative methods. It would be valuable to understand the extent to which the coating adheres to the steel.

 Secondly, I am curious to know whether the researchers examined the impact of water on these coatings and whether they exhibit good water endurance. Evaluating the performance of the coating in the presence of water would provide insights into its long-term effectiveness.

Lastly, I would be interested to learn if the authors investigated the corrosion properties of these coatings after a certain period of time. Conducting such tests would shed light on the coating's ability to maintain its corrosion inhibition properties over an extended duration.

 

Author Response

Response letter for manuscript

12^th July, 2023

Dear Reviewers:

Thank you for your letter concerning our manuscript entitled “Synergistic effect of Benincasa hispida peel extract and KI on the corrosion inhibition of mild steel in HCl”. We approve of all the comments and suggestions, as well as we have revised the manuscript according to your kind advices and reviewers’ detailed comments. We hope our revision has improved the manuscript to a level of their satisfaction. As is well known to all, sustainability is one of the famous journals. Therefore, we try our best to improve our manuscript before it's accepted. It is very kind of you for giving us the opportunity for amending our manuscript. Enclosed please find the responses to the reviewers. All revisions in the manuscript are marked in highlight. We sincerely hope this manuscript will be finally acceptable to be published on sustainability. Thank you very much for all your help and looking forward to hearing from you soon.

Sincerely,

Qihui Wang

Reviewer 2 Report

The article has a clear and logical structure. Individual chapters have adequate content of text and accompanying images. The authors present things clearly and in an understandable form for the reader. The introduction is logically written and clearly exposed on a solid base of references and highlights the novelty of the present study.

In fact, each part of the manuscript was carefully constructed and extensively described.  

The experimental procedure is clearly exposed and the results and discussion are extensively detailed.

In conclusion, I can only appreciate the amount of work presented by the authors and as some minor aspects (row 113 - cm2; double check for spelling) will be addressed by the authors the manuscript can be published with minor changes.

Author Response

Response letter for manuscript

12^th July, 2023

Dear Reviewers:

Thank you for your letter concerning our manuscript entitled “Synergistic effect of Benincasa hispida peel extract and KI on the corrosion inhibition of mild steel in HCl”. We approve of all the comments and suggestions, as well as we have revised the manuscript according to your kind advices and reviewers’ detailed comments. We hope our revision has improved the manuscript to a level of their satisfaction. As is well known to all, sustainability is one of the famous journals. Therefore, we try our best to improve our manuscript before it's accepted. It is very kind of you for giving us the opportunity for amending our manuscript. Enclosed please find the responses to the reviewers. All revisions in the manuscript are marked in highlight. We sincerely hope this manuscript will be finally acceptable to be published on sustainability. Thank you very much for all your help and looking forward to hearing from you soon.

Sincerely,

Qihui Wang

Author Response File: Author Response.docx

Reviewer 3 Report

The work studied the corrosion inhibition synergistic effect between BHPE and KI for mild steel in an acidic solution. The study showed that mixing an optimum KI concentration with different BHPE concentrations yields better inhibitor performance. Overall, the work is good. However, many points need to be considered, as shown below:

 

Introduction:

Well written and comprehensive.

 

Experimental work:

 

-       It is better to use “M” instead of mol/L

-       Line 113: “to expose an exposed area of 1.0 cm2” Please consider rewriting it.

-       Line 114-115: Grinding is achieved via SiC paper, and polishing needs a cloth. As far as I am aware, mirror-like comes only after polishing using Colloidal silica. Did the author use the same surface preparation for all samples (surface analysis samples and electrochemical analysis samples)? If so, there is no need to repeat the surface preparation method in every single section of the Material and Method.

 

Results:

 

-       Line 183: “different corrosion solutions” should be “different corrosive solutions”

-       Line 191-192:” This indicates that the BHPE hinders the charge transfer process from making the mild steel protected” weak sentence; please consider rewriting it.

-       Table 2: The unit of CPE is absolutely wrong; the authors must double-check these staff.

-       Table 2: Many of the n1 values are 1. Note that when n=1, CPE is a pure capacitor, which is not the case here. It is clear from Fig.3 that the centres of all the semicircles in the Nyquist plots are depressed below the x-axis, indicating non-perfect behaviour. Thus, the authors need to refit all the data with adding Chi-squared to the table.

-       Line 338-339: What is meant by mixed adsorption behaviour? Did the author mean chemisorption and physisorption? Please cite a reference as well.

 

Many English mistakes were spotted; please revise the language of the whole manuscript.

 

Many English mistakes were spotted in the manuscript.

Author Response

Response letter for manuscript

12^th July, 2023

Dear Reviewers:

Thank you for your letter concerning our manuscript entitled “Synergistic effect of Benincasa hispida peel extract and KI on the corrosion inhibition of mild steel in HCl”. We approve of all the comments and suggestions, as well as we have revised the manuscript according to your kind advices and reviewers’ detailed comments. We hope our revision has improved the manuscript to a level of their satisfaction. As is well known to all, sustainability is one of the famous journals. Therefore, we try our best to improve our manuscript before it's accepted. It is very kind of you for giving us the opportunity for amending our manuscript. Enclosed please find the responses to the reviewers. All revisions in the manuscript are marked in highlight. We sincerely hope this manuscript will be finally acceptable to be published on sustainability. Thank you very much for all your help and looking forward to hearing from you soon.

Sincerely,

Qihui Wang

Author Response File: Author Response.docx

Reviewer 4 Report

1.     Some gramma errors need to be corrected, like line 60 ‘I-’, line 113, line 217, etc.

2.     More relevant work needs to be added to analyze the peak in FTIR spectrum.

3.     The definition of x² in Table 2 needs to be added and the change of corresponding value should be explained. Latest relevant work can be useful:

(1) Liao, B., Ma, S., Zhang, S., Li, X., Quan, R., Wan, S., & Guo, X. (2023). Fructus cannabis protein extract powder as a green and high effective corrosion inhibitor for Q235 carbon steel in 1 M HCl solution. International Journal of Biological Macromolecules, 239, 124358.

(2) Liao, B., Luo, Z., Wan, S., & Chen, L. (2023). Insight into the anti-corrosion performance of Acanthopanax senticosus leaf extract as eco-friendly corrosion inhibitor for carbon steel in acidic medium. Journal of Industrial and Engineering Chemistry, 117, 238-246.

4.      Please explain why the more compact corrosion inhibitor molecules accumulated on the anode surface can cause the negative shift of corrosion potential.

5.     The differences for Fig. 8c and g are minor, localized corrosion in Fig. 8c can be shown in the enlarged view.

6.     As for EDX results, the changes of proportions for Mn, S, P elements are obvious, which are higher than the chemical composition for fresh mild steel. Explain why.

7.     In Eq. (5), Unit for C is mg/L, but in Eq. (6), Unit for Gibbs free energy is J/mol, the molecular weight for BHPE is unknown, how to calculate it.

Minor editing of English language required

Author Response

Response letter for manuscript

12^th July, 2023

Dear Reviewers:

Thank you for your letter concerning our manuscript entitled “Synergistic effect of Benincasa hispida peel extract and KI on the corrosion inhibition of mild steel in HCl”. We approve of all the comments and suggestions, as well as we have revised the manuscript according to your kind advices and reviewers’ detailed comments. We hope our revision has improved the manuscript to a level of their satisfaction. As is well known to all, sustainability is one of the famous journals. Therefore, we try our best to improve our manuscript before it's accepted. It is very kind of you for giving us the opportunity for amending our manuscript. Enclosed please find the responses to the reviewers. All revisions in the manuscript are marked in highlight. We sincerely hope this manuscript will be finally acceptable to be published on sustainability. Thank you very much for all your help and looking forward to hearing from you soon.

Sincerely,

Qihui Wang

Author Response File: Author Response.docx

Round 2

Reviewer 3 Report

The authors have answered all comments.