Nitrogen Doped Superactivated Carbons Prepared at Mild Conditions as Electrodes for Supercapacitors in Organic Electrolyte

Round 1

Reviewer 1 Report

The paper by Mostazo-López et al. deals with the design of Nitrogen Doped Superactivated Carbons Prepared at Mild Conditions as Electrodes for Supercapacitors in Organic Electrolyte. This work is a very good contribution to the field and could be published after major revision as mentioned below:

1. Some recent literature in this field should be cited in the introduction. See for instance: Carbon, 2017, 122, 564-591 and Journal of Physical Chemistry C, 2017, 121, 15188–15197
2. CAs number, purities and provider of all chemicals should be added in the experimental section
3. The paper contains some typographical errors. Please read carefully and correct
4. All abbreviation should be defined when using the first time in the manuscript; What is for instance TPD?
5. Relative error should be added to all values, tables and figures given in the paper. I note that this error should determine the number of digits used after the decimal point.
6. SEM and wettability should be performed and added to the paper
7. Electroactive surface area and not just surface area should be calculated and added to the paper.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

COMMENTS FOR THE AUTHOR:

The reviewed manuscript describes the preparation of activated carbons and modification of samples and their potential use as electrodes for supercapacitors. In general, the experiments, results and their discussion included in the manuscript are presented in convincing manner. I do, however, have some questions, remarks and suggestions which should be considered in order to improve the manuscript prior its publication. They are listed below:

1. For the introduction part, a comprehensive review is needed. For example, the progress of supercapacitors using activated carbons, the effect of porosity on the electrochemical performances, and the effect of heteroatom containing groups (how to prepare the heteroatom doped carbon, etc.) all these should be reviewed.
2. I think it’s interesting to add more reference, for example when the authors explain the effect of nitrogen groups (line 52).
3. In the Materials and methods part, all the details should present, at less some details of the preparation and functionalization methods.
4. In the electro chemical characterization' part, it’s better to write in the first time the name in detail of the PTFE and after that authors can use abbreviation.
5. Authors use a lower currents density (max 1A/g). For interesting applications, higher current densities are needed. Why not use higher current density then 1A/g?
6. Also for the temperature, why the use of higher temperature and why not ambient temperature?
7. Why the authors don’t present the Isotherm of the sample KUA-COOH? I think it’s interesting for the comparison to present all samples. The same for the related heat treated samples of KUA, why not KUA at 500C?
8. How they can explain that after two different treatment and 2 different temperatures,The samples treated at 500C and 800C have exactly the same surface area? Why they don’t present the value of pore diameter of micropore and narrow micropore, they have an important effect on the electrochemical performances of super capacitors.
9. from the table 1. How the authors can explain the no textural difference between samples treated at different temperatures?
10. For the P series, the CV curves do not reveal visible red-ox peaks (Fig. 6) which could be referred to the pseudocapacitance. Could the authors comment this issue?
11. The results presented in the table 4 show that the capacitance of all samples varying from 37 and 41 F/g. So; I think it’s difficult to make comparison of results between samples and try to explain this difference with the chemical functional groups. This difference of 1 or 2 F/g may be due to the experimental errors.
12. I recommend revising the value of the energy density obtained. With lower capacitance I think it’s difficult to have these higher values of energy density.
13. Line 250. I think table 2 and not table 6.2.
14. in the line 211. Authors say that the sample treated at 500C show identical content of oxygen groups. But In the table 2, the sample KUAN500 has 5.1% and the sample KUACONH2-500 has 8%.
15. How the authors can explain the lower specific capacitance of all samples with higher surface area and higher surface chemistry contains. In others works we can find samples with lower surface area then the samples prepared in this work but with higher capacitance and electrochemical performances.
16. why the authors doesn’t present a VC of all sample in three electrode system in order to present the effect of the heteroatom’s on the electrochemical performances ?
17. I think it’s interesting to present except the relationship between resistance and the amount of oxygen determined and also between nitrogen contains and the capacitance.
18. Authors present GCD at lower current densities; I would like to see also the GCD at higher current densities, because it’s very interesting for applications.
19. One of the most important keys for super capacitors is the cycling. Authors present the results after 35 cycles, I think it will more interesting if they present the results after large cycles number. Because for the practice, it’s interesting to have supercapacitor keeping their performance after large number of cycles.

Author Response

Please see the attachment. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

authors addressed most of my comments. Paper could be published now in Carbon.

Reviewer 2 Report

Dear Authors, 
Firstly i would like to thank you for your answers to all our comments and for the quality of the scientific discussion.
congratulations for the quality of your work.
best wishes

A Elmouwahidi