Effect of Nitrogen Atoms in the CNT Structure on the Gas Sensing Properties of PANI/CNT Composite

Round 1

Reviewer 1 Report

In the paper, “Effect of nitrogen atoms in the CNT structure on the gas sens-2 ing properties of PANI/CNT composite”, the authors presented an interesting study on the morphology, structure, and gas sensitivity to 9 ammonia of composites based on carbon nanotubes (CNTs) with different nitrogen contents. I commend the authors for their work and I recommend the manuscript published with minor revisions. Please check:

1. I think the subgraphs of Figure 4 should be arranged horizontally.

2. Why did the authors choose the to dope with 2 at.% and 4% N atoms into CNTs.

3. I think Figure 6 and 7 is too big, the authors could replot it.

Author Response

We thank the reviewer for their detailed consideration of our manuscript. We hope that after our revisions the manuscript has become better and meets the requirements of the Applied Sciences for published articles.

In the paper, “Effect of nitrogen atoms in the CNT structure on the gas sens-2 ing properties of PANI/CNT composite”, the authors presented an interesting study on the morphology, structure, and gas sensitivity to 9 ammonia of composites based on carbon nanotubes (CNTs) with different nitrogen contents. I commend the authors for their work and I recommend the manuscript published with minor revisions. Please check:

• I think the subgraphs of Figure 4 should be arranged horizontally.

In accordance with the remark, we have rebuilt figure 4 in a horizontal view.

• Why did the authors choose the to dope with 2 at.% and 4% N atoms into CNTs.

The upper limit of the nitrogen concentration was chosen because at [N]>at.4%, a critical decrease in the length of nanotubes is observed. [N]=2 at.% was used as an intermediate. The article reflected the reason why nanotubes with a high content of nitrogen were not used. The added part of the text is highlighted in the manuscript.

• I think Figure 6 and 7 is too big, the authors could replot it.

In accordance with the remark, we reduced the size of Figures 6 and 7.

Reviewer 2 Report

In this manuscript, the authors conducted a comparative study of the influence of nitrogen in CNTs on the morphology, atomic and electronic structure of a composite based on PANI and carbon nanotubes and its gas sensitivity to ammonia. It is the reviewer's opinion the comparative study is sound and interesting. To the best of the reviewer's knowledge, the presenting comparative study was not studied before. The reviewer recommends the publication of this manuscript with minor revision.

-Please state the scientific objectives of the work in the Introduction Section and provide an adequate background.

- Provide enough details to allow the comparative study to be reproduced by an independent researcher.

Author Response

We thank the reviewers for their detailed consideration of our manuscript. We hope that after our revisions the manuscript has become better and meets the requirements of the Applied Sciences for published articles.

In this manuscript, the authors conducted a comparative study of the influence of nitrogen in CNTs on the morphology, atomic and electronic structure of a composite based on PANI and carbon nanotubes and its gas sensitivity to ammonia. It is the reviewer's opinion the comparative study is sound and interesting. To the best of the reviewer's knowledge, the presenting comparative study was not studied before. The reviewer recommends the publication of this manuscript with minor revision.

• Please state the scientific objectives of the work in the Introduction Section and provide an adequate background.

In accordance with the remark, we rewrote the introduction taking into account the wishes of the reviewer.

• Provide enough details to allow the comparative study to be reproduced by an independent researcher.

In accordance with the remark, new text has been added:

in section “2.3. Characterization of samples” value of the work function of the HOPG, against which the AFM probe was calibrated;

in section “2.4. Gas sensing" added a method for calculating sensory characteristics.

Reviewer 3 Report

Comments on applsci-1801522

Title: Effect of nitrogen atoms in the CNT structure on the gas sensing properties of PANI/CNT composite

Journal:  MDPI / applied sciences

 

In this manuscript, a comparative study of the morphology, structure, and gas sensitivity to the ammonia of composites based on carbon nanotubes (CNTs) with different nitrogen contents (un-doped uCNTs – 0 at.%, N-CNT – 2 at.%, N+-CNT – 4 at.%) and polyaniline has been done. Polyani-line-carbon nanotube composites were obtained by in-situ chemical oxidative polymerization of aniline.

After a careful peer-reviewing process, I must inform you that, the subject of this paper is interesting and can be considered for publication in applied sciences after MAJOR REVISION. There are some questions about this submission and some critical amendments are necessary for this work for future submissions. The critical  issues are indicated as follows:

 

1.    Typos and grammar errors are common in the manuscript. A considerable number of sentences are not comprehensible, some of which can be due to typos or grammar errors. Careful proofreading is mandatory for this work.

 

2.    The abstract is not well written but some details of the experimental processes were missed in the abstract. Please revise this section. 

 

3.    The last two lines in the abstract must be improved to increase its readability: “The importance of this work and/or future developments/trends”.

 

4.    The state-of-the-art needs to be described more in “Introduction”. Please revise the last paragraph of this section.

 

5.    The new findings related to this work should be stated in the introduction clearly.

 

6.    Authors must show which questions/problems have been answered in this work. In this case, the correct and detailed information about the recent advances in PANI/CNT composite and its application and testing methods must be provided in this manuscript.

 

7.    In this manuscript, results are not well presented, and discussion on the obtained results must be completely provided in this manuscript. As can be seen, a “comprehensive” and “comparative” discussion is missed in this work. This should be provided as well.

 

8.     Authors are encouraged to provide major findings in the conclusions section with bullet-point style.

 

9.    There is no description of the future plans for research in the first part of the “Conclusions” section. This should be completed in this section.

 

10. Recently published references are beneficial for this work. Please check and use new references focused on your work.

 

11. Also, please double-check and revise the reference list according to the MDPI journal requirements for future re-submission (if available).

 

Author Response

We thank the reviewer for their detailed consideration of our manuscript. We hope that after our revisions the manuscript has become better and meets the requirements of the Applied Sciences for published articles.

In this manuscript, a comparative study of the morphology, structure, and gas sensitivity to the ammonia of composites based on carbon nanotubes (CNTs) with different nitrogen contents (un-doped uCNTs – 0 at.%, N-CNT – 2 at.%, N+-CNT – 4 at.%) and polyaniline has been done. Polyani-line-carbon nanotube composites were obtained by in-situ chemical oxidative polymerization of aniline.

After a careful peer-reviewing process, I must inform you that, the subject of this paper is interesting and can be considered for publication in applied sciences after MAJOR REVISION. There are some questions about this submission and some critical amendments are necessary for this work for future submissions. The critical  issues are indicated as follows:

• Typos and grammar errors are common in the manuscript. A considerable number of sentences are not comprehensible, some of which can be due to typos or grammar errors. Careful proofreading is mandatory for this work.

In accordance with the remark, proofreading of the text of the manuscript was carried out.

• The abstract is not well written but some details of the experimental processes were missed in the abstract. Please revise this section.

In accordance with the remark, we have rewritten the abstract indicating all the main results of the work.

• The last two lines in the abstract must be improved to increase its readability: “The importance of this work and/or future developments/trends”.

Due to the limited size of the abstract, “The importance of this work and/or future developments/trends” is included in the conclusion.

• The state-of-the-art needs to be described more in “Introduction”. Please revise the last paragraph of this section.

In accordance with the remark, the introduction has been rewritten.

• The new findings related to this work should be stated in the in the introduction clearly.

In accordance with the remark, changes were made to the text of the introduction.

• Authors must show which questions/problems have been answered in this work. In this case, the correct and detailed information about the recent advances in PANI/CNT composite and its application and testing methods must be provided in this manuscript.

In accordance with the remark, we rewrote the introduction, taking into account the wishes of the reviewers.

• In this manuscript, results are not well presented, and discussion on the obtained results must be completely provided in this manuscript. As can be seen, a “comprehensive” and “comparative” discussion is missed in this work. This should be provided as well.

We have added to the text of the manuscript a comparison of the sensory characteristics obtained by us with other works.

• Authors are encouraged to provide major findings in the conclusions section with bullet-point style.

In accordance with the remark, the conclusions have been changed and lined up logically by dividing them into paragraphs.

• There is no description of the future plans for research in the first part of the “Conclusions” section. This should be completed in this section.

In accordance with the remark in the "Conclusion" part, plans for further research are given.

• Recently published references are beneficial for this work. Please check and use new references focused on your work.

In accordance with the comment, we have added new references to the manuscript.

• Also, please double-check and revise the reference list according to the MDPI journal requirements for future re-submission (if available).

In accordance with the remark, we have re-edited the reference list.

 

Round 2

Reviewer 3 Report

No more comments