Hydrogen Horizons: A Bibliometric Review of Trends in Diverse Emission Sectors
Round 1
Reviewer 1 Report
1- The studies you reviewed are old, it is suggested to use newer studies and more reliable databases.
2- The language of the article needs to be revised.
3- The review section on past studies should be presented as a sub-section of the introduction.
4- More studies should be examined and the advantages and disadvantages of these studies should be examined in the form of a table in order to determine the main challenge of the study.
5- Figure (2) is of low quality.
6- Provide related references for figures 3 to 6.
7- Provide relevant references for tables 2 to 6.
8- Considering that the intended study is a review, the conclusion is expected to be more comprehensive and clearer.
9- The section related to future studies should be added at the end of the conclusion
Extensive editing of English language required
Author Response
Good afternoon,
Thank you for your time and your suggestions. Answers for each comment are available below.
1- The studies you reviewed are old, it is suggested to use newer studies and more reliable databases.
The SCOPUS database was chosen because it provides access to a huge number of indexed articles and is a powerful database with extensive sorting, ranking and refinement options. The aim of the bibliometric analysis is to determine, among other things, the research trends of the research object. The article represents the current situation and describes the publications with the most citations, so the analysis of older articles appears in the article.
2- The language of the article needs to be revised.
The recommendation was taken into account, corrections were made.
3- The review section on past studies should be presented as a sub-section of the introduction.
The recommendation was taken into account, corrections were made.
4- More studies should be examined and the advantages and disadvantages of these studies should be examined in the form of a table in order to determine the main challenge of the study.
The recommendation was taken into account, corrections were made (Table 1).
5- Figure (2) is of low quality.
Image quality was improved.
6- Provide related references for figures 3 to 6.
The following figures describe the trends among the articles found using the described search conditions in the SCOPUS database. It is authors own elaboration. Considering the large number of references (1012 articles) used to develop the information presented, we are unable to add all of them.
7- Provide relevant references for tables 2 to 6.
The following figures describe the trends among the articles found using the described search conditions in the SCOPUS database. The authors are unable to add all 1012 articles as references.
8- Considering that the intended study is a review, the conclusion is expected to be more comprehensive and clearer.
A discussion section was added to the paper.
9- The section related to future studies should be added at the end of the conclusion
The recommendation was taken into account, corrections were made.
10 - Extensive editing of English language required
English grammar revision was made. (English-71185, editing certificate attached)
Author Response File: 
Author Response.pdf
Reviewer 2 Report
This paper uses bibliometric method and software VOSviewer to summarize the research on hydrogen supporting sustainable development goals in different sectors. The search term is reasonable, the analysis is in-depth, the result is correct and the conclusion is clear. In particular, the analysis of research hotspots in different industries in recent years can provide an overview and help for researchers in different fields of hydrogen energy to support the Sustainable Development goals.
The shortcomings of the paper include:
1. Is "energy sectors" appropriate in the title? After all, the six sectors discussed are not just the energy sector.
2. In “Materials and Methods”, it only introduces the principle of VOSviewer econometric analysis in theory, but it does not give the meaning explanation of some letters, and does not give an example illustration combined with the research theme words of this paper. It is recommended to add these to improve readability and credibility.
3. “SDG” column in Table 1 shows which sustainable development goals are covered in the most cited publications according to the Elsevier SDG data mapping. Please add how to get the Elsevier SDG data mapping.
4. The format of the paper needs to be perfected. Some figures (Figure 17, Figure 18) are too small to see. Some decimal points are written as commas, such as ANC in Table 2.
5. In the "Mean (Year)" column in Table 4, the first refers to the year, and what does the number after the comma refer to?
6. In the "decarbonisation (2022,0)" below Figure 8, what does the "0" in parentheses refer to?
Due to the depth of this review, it is suggested to be revised and published according to the above comments.
Author Response
- Is "energy sectors" appropriate in the title? After all, the six sectors discussed are not just the energy sector.
The recommendation was taken into account, corrections were made. The new title is "Hydrogen Horizons A Bibliometric Review of Trends in Diverse Emission Sectors"
- In “Materials and Methods”, it only introduces the principle of VOSviewer econometric analysis in theory, but it does not give the meaning explanation of some letters, and does not give an example illustration combined with the research theme words of this paper. It is recommended to add these to improve readability and credibility.
The recommendation was taken into account, corrections were made.
- “SDG” column in Table 1 shows which sustainable development goals are covered in the most cited publications according to the Elsevier SDG data mapping. Please add how to get the Elsevier SDG data mapping.
The suggestion was taken into account, the article was supplemented with relevant information.
- The format of the paper needs to be perfected. Some figures (Figure 17, Figure 18) are too small to see. Some decimal points are written as commas, such as ANC in Table 2.
The recommendation was taken into account, corrections were made.
- In the "Mean (Year)" column in Table 4, the first refers to the year, and what does the number after the comma refer to?
The suggestion was taken into account, typographical errors were corrected.
- In the "decarbonisation (2022,0)" below Figure 8, what does the "0" in parentheses refer to?
The suggestion was taken into account, typographical errors were corrected.
Reviewer 3 Report
Dear Authors,
The paper is well-written. However, I have the following comment
1- I hold significant reservations regarding the query used in your research. Given that green hydrogen can be produced through various methods, many papers related to this subject may not include the terms "hydrogen" or "H2" in their abstract, title, or keywords. I strongly suggest expanding your query to encompass all known production methods for green hydrogen.
Similarly, the use of "sdg OR 147" or "sustainable development goal*" or "sustainability" in your query may exclude relevant research. Not all papers addressing sustainability necessarily employ these specific terms. Therefore, I recommend refining your query to ensure that it more accurately represents the breadth of research in the fields of green hydrogen and sustainability, as an example some Authors may use the word sustainable development instead of "sustainability".
2-Please improve the resolution of the all figures
3-Please add the discussion section
4-Please write of aim the paper at the end of the Introduction
5-Please reorder the table, Table 5 come before Table 4
6-Please review all the references, I found several mistakes, such as "International Journal if Hydrogen", it should be "International Journal of Hydrogen" and in the other references, the journal name is missing, For example, reference number 8.
Good luck
Author Response
1- I hold significant reservations regarding the query used in your research. Given that green hydrogen can be produced through various methods, many papers related to this subject may not include the terms "hydrogen" or "H2" in their abstract, title, or keywords. I strongly suggest expanding your query to encompass all known production methods for green hydrogen.
Similarly, the use of "sdg OR 147" or "sustainable development goal*" or "sustainability" in your query may exclude relevant research. Not all papers addressing sustainability necessarily employ these specific terms. Therefore, I recommend refining your query to ensure that it more accurately represents the breadth of research in the fields of green hydrogen and sustainability, as an example some Authors may use the word sustainable development instead of "sustainability".
The recommendations were taken into account, the analysis was supplemented with the terms "sustainable", "sustainable development", "sustainability assessment", "sustainable energy", "sustainable energy systems".
When examining how the number of results increases when "electrolysis" or "methanation" is added to the keywords, it was concluded that the number of results did not increase significantly. Thus, the number of results obtained with the keyword "electrolysis" increased by less than 30 publications, while the number of results obtained with the keyword "methanation" increased by less than 10 publications. However, the mentioned concern was taken into account and a corresponding addition to the limitations section was made.
2-Please improve the resolution of the all figures
Image quality was improved.
3-Please add the discussion section
A discussion section was added to the paper.
4-Please write of aim the paper at the end of the Introduction
The aim of the study is stated at the end of the introduction.
5-Please reorder the table, Table 5 come before Table 4
The numbering of tables and figures was revised.
6-Please review all the references, I found several mistakes, such as "International Journal if Hydrogen", it should be "International Journal of Hydrogen" and in the other references, the journal name is missing, For example, reference number 8.
The source list was revised and corrected.
Round 2
Reviewer 1 Report
The revised version of the article has not made significant progress. Of course, minor changes can be seen in the text of the article.Minor editing of English language required.
Author Response
Dear reviewer,
Thank you for your comments.
It is unfortunate to hear that you did not see much progress. But we accept this evaluation, obviously, and will consider this experience also in our further work. Perhaps we did not explain well enough beforehand what was changed in the article because based on the recommendations of the first round of reviews, we have supplemented the literature review, significantly expanded the keyword analysis to include additional terms related to sustainability, and also corrected/updated the analysis and discussion part. But, of course, it can always be better.
Despite the previously performed proofreading of a native speaker (certificate attached previously), we indeed found existing spelling errors. Your comment about needed language corrections has been taken into account. We have corrected the remaining language errors in the final version of the article (file with track changes attached).
Thank you once again for your time.
Respectfully,
Authors
Author Response File: Author Response.pdf
Reviewer 3 Report
Dear Authors,
Thank you for your response. I think is the paper is ready for publication now.
I noticed several typos, therefore I highly recommend you to send the paper for proofreading.
Good Luck.
Author Response
Dear reviewer,
Thank you for your comments. The article has been proofread by a native speaker. We have fixed the remaining bugs in the latest version (file attached).
Authors
Author Response File: Author Response.pdf
Round 3
Reviewer 1 Report
The article can be accepted.
