Facile Fabrication of SrTiO₃/In₂O₃ on Carbon Fibers via a Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript presented “Facile Fabrication of SrTiO3/In2O3 on the Carbon Fibers vis a 2 Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production”. The manuscript is of interest as the authors discussed their significantly enhanced photocatalytic H₂ generation. The topic is appropriate, but the manuscript language expression needs improvement, some formatting errors and technical information are missing. In addition, further discussions are required. Therefore, a MAJOR REVISION is suggested., Here are some comments:

 

1.    As Strontium titanate (SrTiO₃) is a perovskite oxide with interesting properties such as high dielectric constant, ferroelectricity, and photocatalytic activity. Indium oxide (In₂O₃), on the other hand, is a semiconductor material known for its transparency and electrical conductivity. The Introduction needs more discussion on the CF/SrTiO3/In₂O₃ heterojunction, authors should compare in tabulated form and discuss their nanocomposites novelty and significance w.r.t some other SrTiO3 based photocatalyst for similar application. Why CF was selected it can be explained well.

2.      All Figures needs detailed captions. In fact, in some picture labeling is also required to clarify that which findings belongs to which material.

3.      There are formatting mistakes in the text and in the citation of the references. The format of the reference in the text is not similar e., look ref no 8, 9, 10 11.

4.     Authors should also include XRD of SrTiO3. Similarly, some other characterization techniques EPR, TGA, EIS or the hydrogen generation reported do not show individual characterization or behavior of CF, SrTiO3, SrTiO3/In2O3, In2O3 respectively in comparison to composite CF/SrTiO3/In2O3 which is reported as best among them for hydrogen generation. For a complete comparative analysis these findings are must.

5.     The EIS data presented in not convincing the author should provide with new measurements.

Comments on the Quality of English Language

 

 

 

Author Response

Dear Ms. Emma Yu and Reviewers:

  Recently, I was sick, so please forgive me for not submitting the revised draft until today.

Thank you for your letter and the reviewers’ comments concerning our manuscript entitled “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers via a self-assembly strategy for enhanced photocatalytic hydrogen production” (ID: sustainability-2874320). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections which we hope meet with approval. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions marked in red in the paper. The responses to the reviewer's comments are also marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

 

Sincerely.

Niu Jiantao

 

Reviewer #1:

Q1. As Strontium titanate (SrTiO₃) is a perovskite oxide with interesting properties such as high dielectric constant, ferroelectricity, and photocatalytic activity. Indium oxide (In₂O₃), on the other hand, is a semiconductor material known for its transparency and electrical conductivity. The Introduction needs more discussion on the CF/SrTiO₃/In₂O₃ heterojunction, authors should compare in tabulated form and discuss their nanocomposites novelty and significance w.r.t some other SrTiO3 based photocatalyst for similar application. Why CF was selected it can be explained well.

Response:

After literature review, it is found that there are few literatures about the preparation of SrTiO₃/In₂O₃ materials, but there are few reports about using SrTiO₃/In₂O₃ as photocatalyst materials. This paper introduces the SrTiO₃/In₂O₃ heterojunction on the surface of carbon fibers and its photocatalytic properties. In the preface, the performance of carbon fiber is introduced, which answers why carbon fiber is used as carrier material.

 

Q2. All Figures needs detailed captions. In fact, in some picture labeling is also required to clarify that which findings belongs to which material.

Response:

According to your suggestion, detailed captions of different samples are added to all Figures. Thanks.

Q3. There are formatting mistakes in the text and in the citation of the references. The format of the reference in the text is not similar e., look ref no 8, 9, 10 11.

Response:

According to your suggestion, the labeling method of references in this text has been revised. Thanks.

 

Q4. Authors should also include XRD of SrTiO₃. Similarly, some other characterization techniques EPR, TGA, EIS or the hydrogen generation reported do not show individual characterization or behavior of CF, SrTiO₃, SrTiO₃/In₂O₃, In₂O₃ respectively in comparison to composite CF/SrTiO3/In2O3 which is reported as best among them for hydrogen generation. For a complete comparative analysis these findings are must.

Response:

According to your suggestion, XRD of SrTiO₃ has been added.The properties of CF/SrTiO₃ have been reported in the previous series of papers, but some performance tests cann't be increased at present, please forgive me.

 

Reviewer 2 Report

Comments and Suggestions for Authors

• *In the introduction, include more information about the problems being studied in the manuscript and add more details about the uses of photocatalysts.

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• *In the experimental section, provide additional information about the synthesis process and the characteristics of the equipment used in material characterization.

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• *Integrate more details about the synthesis method into the introduction.

•  

• *Include a possible mechanism for material formation.

•  

• *Although the XRD results are interesting, it is recommended to conduct a more in-depth analysis of the obtained samples.

•  

• *Add a size distribution analysis to Figure 5.

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• *In the subsequent section of the manuscript, it is advisable to include more information: "...and the excellent electrical conductivity of the carbon fibers promotes the separation, generation, and migration of photogenerated electron-hole pairs in the composite fiber materials, enhancing the photocatalytic hydrogen evolution performances."
•  

• *Include a comparative table of the results obtained from photocatalysis with other similar works.

•  

• *It is recommended to conduct a more thorough analysis of the following lines in the manuscript: "According to the previous research results, the band gap of the pure SrTiO3 sample is 3.32 eV, the conduction band position is -0.55 eV, and the valence band position is 2.77 eV. According to literature reports[35].

Author Response

Dear Ms. Emma Yu and Reviewers:

  Recently, I was sick, so please forgive me for not submitting the revised draft until today.

Thank you for your letter and the reviewers’ comments concerning our manuscript entitled “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers via a self-assembly strategy for enhanced photocatalytic hydrogen production” (ID: sustainability-2874320). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections which we hope meet with approval. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions marked in red in the paper. The responses to the reviewer's comments are also marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

 

Sincerely.

Niu Jiantao

Q1. In the introduction, include more information about the problems being studied in the manuscript and add more details about the uses of photocatalysts.

Response:

Relevant references have been added in the introduction, and the language in the introduction has been modified.

 

Q2. In the experimental section, provide additional information about the synthesis process and the characteristics of the equipment used in material characterization.

Response:

According to your suggestion, “2.1. Materials and Main Equipment” are added in the experimental section, and the names and characteristics of equipments used in the process of material synthesis are introduced.

 

Q3. Integrate more details about the synthesis method into the introduction.

Response:

According to your suggestion, more material synthesis details and corresponding references have been added in the section "2.2 ", and the part has been adjusted and modified.

 

Q4. Although the XRD results are interesting, it is recommended to conduct a more in-depth analysis of the obtained samples.

Response:

The characteristic diffraction peaks of In₂O₃ were not clearly observed in XRD pattern, but the lattice (0.297 nm) belonging to IN₂O₃ was observed in TEM.

 

Q5. Add a size distribution analysis to Figure 5.

Response:

According to your suggestion, add a size distribution analysis to figure 5.

 

Q6. In the subsequent section of the manuscript, it is advisable to include more information: "...and the excellent electrical conductivity of the carbon fibers promotes the separation, generation, and migration of photogenerated electron-hole pairs in the composite fiber materials, enhancing the photocatalytic hydrogen evolution performances."

Response:

According to your suggestion, the subsection section of the manuscript has been modified. Thanks.

 

Q7. It is recommended to conduct a more thorough analysis of the following lines in the manuscript: "According to the previous research results, the band gap of the pure SrTiO₃ sample is 3.32 eV, the conduction band position is -0.55 eV, and the valence band position is 2.77 eV. According to literature reports[35].

Response:

According to your construction, a more analysis to the band gap of the pure SrTiO₃ sample has been conducted, the related references have been added.

Reviewer 3 Report

Comments and Suggestions for Authors

I reviewed the manuscript “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers vis a self-assembly strategy for enhanced photocatalytic hydrogen production”. Overall, the manuscript is written in good scientific language. To confirm their hypotheses, the authors used the strong methods of physico-chemical analysis. They draw on current literature to compare the results with those of other research groups. There are some minor comments to the manuscript, the main one of which concerns the description of the experiment.

Make sure that there are no typos in the title. What 'vis' mean? Why the fabrication is ‘facile’? I haven’t seen any comparisons with other methods, which probably are more difficult.

Lines 18-20, line 52. Please, paraphrase the sentences to avoid the excessive repetitions.

Lines 55, 61 and further. The references are formalized not according to the journal’s guide.

 The experimental description was not provided in a clear way. Section 2.2 left me with many questions regarding details of the carbonization, loading of the layers, solvothermal treatment conditions, etc. Then, in section 2.2.1 called ‘Preparation of Tencel Fiber/SrTiO3’, one can find some details and conditions of the composite production. Is it the same one as described in 2.2? Why indium appeared in the part 2.2.1 about Tencel Fiber/SrTiO₃? Probably, it would be better to reorganize the text in the way when everything is coming with the details in a more logical order. What is the point of making 2.2. and 2.2.1. if there is no 2.2.2? Now, these two subsections are confusing.

2.2.1. What chemically happened to the In seeds during solvothermal reaction?

Line 132. What previous references?

Lines 138, 192, 196. PDF#35-0734? Is it about JCPDS Cards?

Line 167. What I can observe in fig. 3,e is that the nanoplates diameters are bigger than the scale bar of 300 nm. So, the term nano is doubtful.

Line 168. In2O₃

Line 166. If there is a paste structure, what was meant to be on XRD? Does it mean that indium oxide is amorphous?

Figure 6 lacks a, b, c, d… and their description. Also, it is difficult to see the white elements names on the colored background (left up corner).

Provide doi for the references.

Author Response

Dear Ms. Emma Yu and Reviewers:

  Recently, I was sick, so please forgive me for not submitting the revised draft until today.

Thank you for your letter and the reviewers’ comments concerning our manuscript entitled “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers via a self-assembly strategy for enhanced photocatalytic hydrogen production” (ID: sustainability-2874320). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections which we hope meet with approval. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions marked in red in the paper. The responses to the reviewer's comments are also marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

 

Sincerely.

Niu Jiantao

Q1. Make sure that there are no typos in the title. What 'vis' mean? Why the fabrication is ‘facile’? I haven’t seen any comparisons with other methods, which probably are more difficult.

Response:

"vis" should be "via", and the letter is misspelled. Thanks.

 

Q2. Lines 18-20, line 52. Please, paraphrase the sentences to avoid the excessive repetitions.

Response:

This section has been modified. Thanks.

 

Q3. Lines 55, 61 and further. The references are formalized not according to the journal’s guide.

Response:

The format of references has been uniformly revised, thank you.

 

Q4.  The experimental description was not provided in a clear way. Section 2.2 left me with many questions regarding details of the carbonization, loading of the layers, solvothermal treatment conditions, etc. Then, in section 2.2.1 called ‘Preparation of Tencel Fiber/SrTiO3’, one can find some details and conditions of the composite production. Is it the same one as described in 2.2? Why indium appeared in the part 2.2.1 about Tencel Fiber/SrTiO₃? Probably, it would be better to reorganize the text in the way when everything is coming with the details in a more logical order. What is the point of making 2.2. and 2.2.1. if there is no 2.2.2? Now, these two subsections are confusing.

Response:

The subhead 2.2.1 is redundant and has been deleted. In addition, the word order of this part has been modified and the text has been reorganized. Thank you.

 

Q5.  Line 132. What previous references?

Response:

This section has been modified, thank you.

 

Q6.  Lines 138, 192, 196. PDF#35-0734? Is it about JCPDS Cards?

Response:

Yes, it is about JCPDS Cards, and the whole text has been revised.

 

Q7. Line 167. What I can observe in fig. 3,e is that the nanoplates diameters are bigger than the scale bar of 300 nm. So, the term nano is doubtful.

Response:

Fig. 3 (c) is a partial enlarged view of the CF/SrTiO₃ fiber material in fig. 3 (b). In this part, the order of statements in the paper may easily lead to misunderstanding, and we have revised the corresponding part of the paper.

 

Q8. Line 168. In₂O₃

Response:

Thank you, we have made relevant changes.

 

Q9. Line 166. If there is a paste structure, what was meant to be on XRD? Does it mean that indium oxide is amorphous?

Response:

In the XRD test, the obvious diffraction peak of In₂O₃ can't be detected, which may be due to the low content of In₂O₃ or the amorphous structure as you said, which needs further study. In future experiments, we may make further analysis.

 

Q10. lacks a, b, c, d… and their description. Also, it is difficult to see the white elements names on the colored background (left up corner).

Response:

These have been revised and improved according to your suggestion, thank you.

Reviewer 4 Report

Comments and Suggestions for Authors

The paper entitled “Facile Fabrication of SrTiO3/In2O3 on the Carbon Fibers vis a 2 Self-Assembly Strategy for Enhanced Photocatalytic Hydrogen Production focuses on carbon fiber as the support in enhancing the generation and migration of photogenerated electrons and preventing the recombination of photogenerated electron-hole pairs. This is a good study to be considered as publication.

The following comments are recommended for the author to be considered:

-The introduction is short and compared to the existing literature needs to add more references and compare the scientific aspect of this manuscript with other available works.

- If possible for the authors to do, I would recommend to further strengthen the manuscript by more characterizations (photoluminescaence, Raman Spectroscopy, ect).

-I would recommend to compare the efficiency of the photo-catalytic materials of the current manuscript with the same range of materials used carbon fiber for enhancing charge transfer due to the conductivity of the carbon in a table.

Comments on the Quality of English Language

Spell and grammar check in proofreading

Author Response

Dear Ms. Emma Yu and Reviewers:

  Recently, I was sick, so please forgive me for not submitting the revised draft until today.

Thank you for your letter and the reviewers’ comments concerning our manuscript entitled “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers via a self-assembly strategy for enhanced photocatalytic hydrogen production” (ID: sustainability-2874320). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections which we hope meet with approval. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions marked in red in the paper. The responses to the reviewer's comments are also marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

 

Sincerely.

Niu Jiantao

Q1. The introduction is short and compared to the existing literature needs to add more references and compare the scientific aspect of this manuscript with other available works.

Response:

Thank you for your suggestion. We have modified and added the introduction. Thank you.

 

Q2. If possible for the authors to do, I would recommend to further strengthen the manuscript by more characterizations (photoluminescaence, Raman Spectroscopy, ect).

Response:

Thank you for your advice. At present, there is no condition to add more tests for this paper, but we will add more test representations in the later research and paper publication.

Reviewer 5 Report

Comments and Suggestions for Authors

The research was written in a smooth manner and simple language that makes it easy for readers from different fields to comprehend most of its points. The research is of interest to the journal reader, however, there are some aspects that need to be changed or made clearer before this work can be accepted in this prestigious journal.

1-      The manuscript needs a language check from the beginning to the end.

2-      When compared to other published works on the same subject, what novel perspectives does the presented work provide?

3-      In section 2.4, line 132, some references should me mentioned instead of the word (previous references).

4-      In X-ray results, it is better to index (hkl) all peaks on the graph relative to the corresponding PDF cards.

5-      Figure 12 “Electrochemical Impedance Spectra” needs more explanations with some supported references.

6-      In figure 12, the shift in CF compared to the CF/SrTiO3/In2O3 and CF/SrTiO3 should be state.

7-      How the energy band gap was obtained from figure 13?. Some suggested previous work to the authors, i) https://www.mdpi.com/2571-6131/5/4/80,

 ii) https://doi.org/10.1016/j.solmat.2007.05.005,

 iii) https://doi.org/10.1016/j.jallcom.2023.172845,

iv) https://doi.org/10.1007/s10854-020-03717-9

8-      In line 329 “According to the experimental results in Chapter 2 and the previous XPS and EPR test 329 results, it can be known that both SrTiO3 and In2O3 materials in the CF/SrTiO3/In2O3 composite fiber material have a large number of oxygen vacancies.”. The word chapter should be replaced by section.

9-      The Conclusions must be shortened.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

Dear Ms. Emma Yu and Reviewers:

  Recently, I was sick, so please forgive me for not submitting the revised draft until today.

Thank you for your letter and the reviewers’ comments concerning our manuscript entitled “Facile fabrication of SrTiO₃/In₂O₃ on the carbon fibers via a self-assembly strategy for enhanced photocatalytic hydrogen production” (ID: sustainability-2874320). Those comments are valuable and very helpful. We have read through comments carefully and have made corrections which we hope meet with approval. Based on the instructions provided in your letter, we uploaded the file of the revised manuscript. Revisions marked in red in the paper. The responses to the reviewer's comments are also marked in red and presented following.

We would love to thank you for allowing us to resubmit a revised copy of the manuscript and we highly appreciate your time and consideration.

Sincerely.

Niu Jiantao

Q1. The manuscript needs a language check from the beginning to the end.

Response:

Thank you for your suggestion. We have reconfirmed and revised the manuscript.

 

Q2. When compared to other published works on the same subject, what novel perspectives does the presented work provide?

Response:

There are few reports about using SrTiO₃/In₂O₃ as photocatalyst materials. In this paper, we successfully prepared a double-layer core-shell structure of CF/SrTiO₃/In₂O₃ photocatalytic composite fiber, through loading in seeds first, and then by solvothermal method and in-situ growth method, finally studied the mechanism of photocatalytic decomposition of water to produce hydrogen.

 

Q3. In section 2.4, line 132, some references should me mentioned instead of the word (previous references).

Response:

Thank you for your correction. We have made relevant amendments and improvements.

 

Q4. In X-ray results, it is better to index (hkl) all peaks on the graph relative to the corresponding PDF cards.

Response:

In Figure 2, the standard diffraction peaks of SrTiO₃ (JCPDS # 35-0734), In₂O₃ (JCPDS # 06-0416) and the XRD test peaks of SrTiO₃ are added, so there is no index all peaks on the graph.

 

Q5. Figure 12 “Electrochemical Impedance Spectra” needs more explanations with some supported references.

Response:

This section has been revised and relevant supporting references have been added.

 

Q6.  In figure 12, the shift in CF compared to the CF/SrTiO₃/In₂O₃ and CF/SrTiO₃ should be state.

Response:

The analysis maybe not enough. And we will strengthen the study and research in this area in the later period.

 

Q7. How the energy band gap was obtained from figure 13?. Some suggested previous work to the authors, i) https://www.mdpi.com/2571-6131/5/4/80,

10. ii) https://doi.org/10.1016/j.solmat.2007.05.005,

 iii) https://doi.org/10.1016/j.jallcom.2023.172845,

10. iv) https://doi.org/10.1007/s10854-020-03717-9

Response:

At your suggestion, we have added relevant references in the paper.

 

Q8.   In line 329 “According to the experimental results in Chapter 2 and the previous XPS and EPR test 329 results, it can be known that both SrTiO3 and In2O3 materials in the CF/SrTiO3/In2O3 composite fiber material have a large number of oxygen vacancies.”. The word chapter should be replaced by section.

Response:

This part has been modified, thank you.

Q9.   The Conclusions must be shortened.

Response:

The conclusion has been revised, thank you.

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors have addressed all the issues. Minor English proof reading is required. 

Comments on the Quality of English Language

Minor English proof reading is required. 

Author Response

We apologize for the poor language of our manuscript. Thank you for your suggestions. According to your advice, We have now worked on both language and readability and have also involved native English speakers for language corrections. We really hope that the flow and language level have been substantially improved.

Author Response File: Author Response.docx

Reviewer 2 Report

Comments and Suggestions for Authors

The authors made the changes to the manuscript

Author Response

We apologize for the poor language of our manuscript. Thank you for your suggestions. According to your advice, We have now worked on both language and readability and have also involved native English speakers for language corrections. We really hope that the flow and language level have been substantially improved.

Author Response File: Author Response.docx