Preparation and Application of Coal-Liquefaction-Residue-Based Carbon Material

Round 1

Reviewer 1 Report

In this manuscript authors have prepared porous carbon from coal liquefaction residue and utilized them for the electrochemical detection of p-nitrophenol. The topic is noteworthy, experiments were conducted well, and the analysis was carefully done. Since the obtained results are of interest for the readers of this Journal, it is recommended for publication after following comments are addressed:

 

1.Give a proper explanation and mechanism for the utilization of KOH.

2.      The manuscript mentions that the coal liquefaction residue-based porous carbon (CLR-PC) material has a porous structure but no characterization has been included. e BET surface area and pore size analysis. must be provided

3.      TEM images of CLR-PC in (Fig.2c, 2d) confirm the porous structure of the CLR-PC material but in the caption, it was written as STM. Give an appropriate explanation.

4.      Equation-1 states that the nitro group of 4-NP goes through a reduction reaction to form hydroxylamine. Please give experimental evidence about the product form.

5.      The EIS measurement of the electrode was carried out in the solution containing 1 mmol·L^-1 [Fe(CN)₆]^3-/4- containing 0.1mol·L^-1 KCl but other experiments were carried out in the PBS buffer solution. Will it affect if the PBS buffer solution is used for EIS measurement? Give an explanation with experimental data.

6.      CLR-PC/GCE electrode was utilized for selective sensing of 4-NP. Why not use 2,4- Di-nitrophenol? Give a proper experimental explanation.

7.      Fig. 9 indicates the interfering substance has a low effect on the detection of 4-NP. But in the manuscript, there is no selectivity data. Please give the experimental evidence for how to select 4-NP. 

8. The manuscript needs to be checked in terms of English clarity and typo errors,and also further relevant reference could be cited; Journal of Environmental Chemical Engineering, 2021, 9, 106656.

 

Author Response

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Author Response File: Author Response.doc

Reviewer 2 Report

Main question addressed by the research: The work addresses the preparation and performance of coal liquefaction residue-based carbon material.

Originality and relevance of the topic: The topic is relevant to the field and it considers a suitable research gap.
Added value of the paper:  The manuscript takes into account the study of this carbon based residue, however the main purpose of it is not clearly stated. The paper should include what aspects are critical for these assessments and clearly explain why they are analysing those and why they are needed at the end of the Introduction.

Quality of figures: Formatting should be consistent and some figures needs corrections such as Figure 6b with the fitting. Where is the x variable?
Specific improvements for the paper to be considered:

1. Abstract is too short and general. It should summarize the main findings and applications of the paper.
   
2. Critical discussion foranalytical application is unclear. No references to discuss about.
3. The selection of the optimal catalytic conditions is unclear.
4. The conclusions are poor and they would need more elaboration so they clearly match the results.

Author Response

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Author Response File: Author Response.docx

Reviewer 3 Report

Author studies the preparation and application of coal liquefaction residue-based carbon material. The manuscript is well written; however, the author needs minor revision before acceptance. Some comments are given below: The first word of the introduction should be capitalized, In section 3.4, it is better to include BET analysis. In section 3.4, the equation can be assigned as a figure. It's better to have a recent 5-year reference.

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

Here are some points were not addressed correctly, for example the following two points were answered by the authors but the references were not added to the references lists

1.Give a proper explanation and mechanism for the utilization of KOH.

Response: Thanks for the good comment from the reviewers. In the synthesis of porous carbon materials generally the KOH as an activator and KOH activation method can produce micropores and mesoporous with small pore size in various structural carbon materials , and improve the micropore and mesoporous ratio of materials. In the revised manuscript the “explanation and mechanism for the utilization of KOH” has a brief explanation and marked with red. (In paragraph 2.2).

1. Just a general introduction is given not proper explanation and mechanism, i am not convinced

2. In addition without a BET results how authors can claim that material is porous and have high surface area. Either they should provide BET analysis or should not claim that material is porous.

3.  Author are claiming about selective detection, while it was not tested with similar compounds.  

 

 

Author Response

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Author Response File: Author Response.doc

Reviewer 2 Report

Paper has significantly improved for publication standards

Author Response

Thanks for the reviewer's comment.

Round 3

Reviewer 1 Report

Revision is Ok, expect the porosity analysis. But manuscript can be accepted for publication in current form.