Perspective of Use of Pd/rGO in a Direct Urea Microfluidic Fuel Cell
, J. C. Cruz 2, F. I. Espinosa-Lagunes 3, A. MartÃnez-Lázaro 4, J. Ledesma-GarcÃa 4, L. G. Arriaga 3,* and R. A. Escalona-Villalpando 4
Round 1
Reviewer 1 Report
In this paper, the authors reported the preparation of Pd/rGO and its application as anode as a urea and urine fuel cell. The performance is quite good. It can be accepted for publication after addressing the following issues.
The first direct urea fuel cell was reported in 2010,
Energy Environ. Sci., 2010, 3, 438–441
This key paper should have been cited in the introduction and relevant parts.
The half cell potential for reaction 1, is also reported in this paper.
The paper above also reported the first urine fuel cell thus should be cited in the part on urine fuel cell too.
page 1, line 43, NHE should be 'SHE'. The original source of the paper mentioned above should be cited here.
In abstract. 'The results show that the mix-21ture of Pd/rGo with Nafion® in the cathode compartment is dispersed and adheres to the paper 22fibers, generating electrical contact giving rise to reactions of interest. ' According to the experimental section, Pd/rGO was used as the ANODE, not cathode. Please have a double check.
page 4, 'The limit currents and 135maximum powers obtained in the performance of the cell were concentrated. ', what do you 'concentrated' here ?
Some key papers regarding urea oxidation and urea fuel cells should have been cited.
Author Response
Concerning the work “Perspective of Use of Pd/rGO in a Direct Urea Microfluidic Fuel Cell” with Submission ID 228062802, that we have submitted for consideration to be published in Catalysis. Here we present the comments related to the points raised by the reviewers that kindly reviewed the first version of the manuscript.
Reviewer #1:
Comments to the Author:
- The first direct urea fuel cell was reported in 2010, Energy Environ. Sci., 2010, 3, 438–441. This key paper should have been cited in the introduction and relevant parts. The half cell potential for reaction 1, is also reported in this paper. The paper above also reported the first urine fuel cell thus should be cited in the part on urine fuel cell too.
Dear reviewer, thank you for your comment. The manuscript has been modified and the recommended reference has been added.
- page 1, line 43, NHE should be 'SHE'. The original source of the paper mentioned above should be cited here.
Dear reviewer, thank you for your comment. The manuscript has been modified.
- In abstract. 'The results show that the mix-21ture of Pd/rGo with Nafion® in the cathode compartment is dispersed and adheres to the paper 22fibers, generating electrical contact giving rise to reactions of interest. ' According to the experimental section, Pd/rGO was used as the ANODE, not cathode. Please have a double check.
Dear reviewer, the document has been double checked and modified.
- page 4, 'The limit currents and 135maximum powers obtained in the performance of the cell were concentrated. ', what do you 'concentrated' here ?
The authors have modified the paragraph for a better understanding considering the concentration where a higher global performance of the fuel cell is obtained.
- Some key papers regarding urea oxidation and urea fuel cells should have been cited.
The manuscript has been modified and the recommended reference has been added.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
In this manuscript, the authors synthesized the Pd/rGO and used it in a direct urea microfluidic fuel cell. Further, the authors optimized basic parameters such as urea, KOH and H2SO4 concentration, and flux rate. The manuscript is suggested to be accepted after the following issues are addressed;
1) In Figures 1a and b, the authors should improve the image quality. The compound name and scale bare are not visible.
2) The author should add more information related to the XRD, such as crystalline size, lattice parameters etc.
3) In Figure 1b, some peaks are indexed; the authors should index all the peaks and also add the Rietveld refinement.
4) To check the composition analysis, the authors should add characterizations such as XPS, EDX etc.
5) When the KOH electrolyte's molarity increases, what is the device's performance?
6) In the materials and method section, the authors should provide information about the source of precursors.
7) There are many terms, such as PMMA; the authors should define them and then use them as abbreviations.
8) The authors should add a comparative table or figure to compare the results with previous results to enhance the device's novelty.
9) Many spelling and formatting typos in this paper, and the authors should check and revise them thoroughly.
Author Response
April 17th, 2023
Dear Professor Dr. Vincenzo Baglio
Editor-in-Chief
Catalysis
Concerning the work “Perspective of Use of Pd/rGO in a Direct Urea Microfluidic Fuel Cell” with Submission ID 228062802, that we have submitted for consideration to be published in Catalysis. Here we present the comments related to the points raised by the reviewers that kindly reviewed the first version of the manuscript.
Reviewer #2:
Comments to the Author
In this manuscript, the authors synthesized the Pd/rGO and used it in a direct urea microfluidic fuel cell. Further, the authors optimized basic parameters such as urea, KOH and H2SO4 concentration, and flux rate. The manuscript is suggested to be accepted after the following issues are addressed.
- In Figures 1a and b, the authors should improve the image quality. The compound name and scale bare are not visible.
Dear reviewer, thank you for your comment. The manuscript has been modified.
- The author should add more information related to the XRD, such as crystalline size, lattice parameters etc.
Dear reviewer, thank you for your comment. Through the analysis by refinement of Rietveld, which is appended in the supplementary information as Fig.S1, the adjustment of the signals was made with the parameters of the crystallographic database (COD Data), where the Bragg equation and Scherrer equation were used to determining FWHM and the size of the particles of the mean peak of the Pd / rGO, where the average value of the crystallite size is 6.40 nm (Table S1), microstrain 3.41x10-3, dislocation density 49.13x10-3 nm-2 (Table S2) and the network parameters of Pd and rGO are observed in Table S3. Finally, the comparison was made with the team's database, so it was compared with JCPDS, which corresponds to the analysis signals of the Pd/Rgo sample, which are annexed in Figure 1b of the manuscript.
- In Figure 1b, some peaks are indexed; the authors should index all the peaks and also add the Rietveld refinement.
Dear reviewer, thank you for your comment. The manuscript has been modified in Figure 1 b, adding the peaks by refinement and network parameters by JCPDS.
- To check the composition analysis, the authors should add characterizations such as XPS, EDX etc.
Dear reviewer, thank you for your comment. The manuscript has been modified by attaching XPS analysis for the analysis of composition and oxidation states before and after microfluidic cell analysis.
- When the KOH electrolyte's molarity increases, what is the device's performance?
As shown in figure 3-b, the OCP, current density and power with the change of KOH can be observed, the following table summarizes the change of these parameters.
|
KOH /mM |
OCP / V |
J / mA cm-2 |
W / mW cm-2 |
|
0.1 |
0.41 |
10 |
2 |
|
0.7 |
0.51 |
25 |
4 |
|
1 |
0.63 |
98 |
16 |
|
2 |
0.72 |
158 |
36 |
|
5 |
0.83 |
160 |
38.5 |
- In the materials and method section, the authors should provide information about the source of precursors.
Dear reviewer, the required information was added.
- There are many terms, such as PMMA; the authors should define them and then use them as abbreviations.
The manuscript has been modified. Polymethyl methacrylate (PMMA).
- The authors should add a comparative table or figure to compare the results with previous results to enhance the device's novelty.
Dear reviewer, thank you for your comment, we add more references to support this information.
- Many spelling and formatting typos in this paper, and the authors should check and revise them thorough.
Dear reviewer, thank you for your comment. The entire document has been thoroughly reviewed as recommended.
Thank you very much in advance for your kind consideration to our work.
Sincerely yours,
Dra. Mayra Polett Gurrola
Earth Sciences Department,
Cátedra-CONACYT-Tecnológico Nacional de México/ Instituto Tecnológico de Chetumal
Av. Insurgentes No. 330, Esq. Andrés Quintana Roo, Colonia David Gustavo Gutiérrez, Apdo. Postal 267 C.P. 77013, Chetumal, Quintana Roo, México
Phone: 52-442-5118545
Email: mayra.pg@chetumal.tecnm.mx
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
Accept in the present form.
