Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols
Round 1
Reviewer 1 Report
Comments to the Author Manuscript catalysts-2051413
Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols. In my opinion this manuscript is very interesting and well-carried study. The experimental approach is sound. The manuscript is well-organized, all the conclusions are supported by the presented data, and authors used advanced methods for characterization of fabricated nanocatalysts such as SEM, TEM, XRD etc.
However, there are some missed points related to manuscript presentation details. Based on these points, this manuscript can be recommended for publication in the journal after major revisions with due consideration of the specific comments below.
1. The introduction section should be carefully revised and a more detailed analysis of the current achievements in the research area should be presented. This section should reflect the most relevant and progressive research on the subject. The relevance and especially the novelty of the research should be written very carefully.
2. Did authors studied reusability of prepared catalysts for several runs?
3. Authors recommended providing comparative catalytic activity data from the previously published studies on the similar reactions.
4. English language and style are fine/minor spell check required
5. The conclusion section should be elaborated and improved. The author should bring specific conclusions in accordance with obtained results.
Author Response
Dear Reviewers,
Thank you for your precious time to constructive comments on our manuscript titled “Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols” for Catalysts (Manuscript ID: catalysts-2051413). We sincerely appreciate your confirmation, questions and advices of our work. Accordingly, we have supplied the corresponding response and revision based on the comments. We sincerely hope that our responses will fully address your concerns about our work.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript entitled “Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols” focus on the synthesis of Ti3C2Tx (T = OH) was prepared from Ti3AlC2 by HF etching. Five samples of Ti3C2Tx were synthesized by varying the exposition time between 24 and 48 h. The synthesized photocatalysts were characterized using various techniques and tested in the photocatalytic reduction of CO2 under visible light. Several comments were raised by analyzing the results presented by the authors. Thus, the authors should compare their results with those recently reported elsewhere in the literature and discuss the advantage of their materials. This analysis is very brief in the present version and should be majorly revisited before the final decision on the acceptance of the article to publication.
I recommend this manuscript to publication only after corrections of following points
Abstract: Line 14: indicate what means "36" in the abbreviation
1- The introduction section should be improved. It is too brief and it lacks objectivity. More content should be added recounting previous recent studies which have been carried out as well as their weakness and why the present study is meaningful and necessary.
Line 29: references 7,8 instead of 7-8
2- Result and discussion
The presentation if Figure 1 should be revisited. Figure of XRD pattern should be presented alone. The XRD peaks aren't legible. Idem for Raman spectra
Line 46: to correct: Diffraction peaks of Ti3C2Tx are correspond to…
Line 46: change the nomenclature: it should be like this: JCPDS No. 52-0875
Lines 46-50: “Stacking peak {002} shifts to lower angle compared with Ti3AlC2, indicating extended interlayer spacing [11]. Ti3C2Tx-36 shows the lowest {002} intensity in all Ti3C2Tx, presenting minimum layer numbers”.
According to the patterns of figure 1, it is impossible to make this remark. The authors should improve the presentation of Figure 1.
Why the sample Ti3C2Tx-36 shows the lowest intensity? Explain.
Line 53: the authors should indicate the value of this vibration on the figure.
Line 58: some of images of figure 2 must be presented as Supplementary information
Lines 65,66: the authors should give more details on the statement “… The stacking layered structure may cause the less active sites exposure.”
Lines 70,71: “The interbedded self-supporting structure not only exposes more active sites but also preserves morphology stability”: more details were needed. The stability of the morphology should be analyzed with thermogravimetric analysis.
Lines 71-75: The obtained S(BET) values are too low so that their evolution is significant.
Line 76: The authors should explain on the statement: “The extended interlayer spacing provides more active sites and benefit for photogenerated carrier diffusion”
Lines 79-82: The XPS results must be interpreted more deeply.
The oxygen atoms detected by the XPS analysis are not all active sites. The authors should be interested to OH groups.
The authors must discuss on the evolution of the percentage of the different O as a function of etching time. They should present the O1s XPS spectra of the different samples.
Line 85: The authors should explain on the statement “… there are few -F function groups after Al removal (Figure S3c-d).”
Line 90: How the authors differentiate the nature of oxygen atoms? they should analyze the samples with FTIR.
Lines 95,96 and figure S4b: The extrapolation to E=0 should be redo. I doubt that Eg=1.26 eV for all samples. Considering your UV-vis spectra and the corresponding Kublka Monk transforms, the Eg should change with the etching time!
Line 101: “reaction” instead of “rection”
Line 145: The authors should explain on the statement “Interbedded self-supporting structure are responsible…”
3- Materials and Methods
- Materials Characterization:
Line 154: The authors must present the characterization techniques in the same order that they appearing in the results.
Lines 158 and 164: repetition
- Photocatalytic reaction:
Line 181: the authors should explain why they used 4°C as a reaction temperature
4- Conclusion:
- Line 193,194: this conclusion requires TG analysis
References:
The authors should add the DOI if possible
Author Response
Dear Reviewers,
Thank you for your precious time to constructive comments on our manuscript titled “Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols” for Catalysts (Manuscript ID: catalysts-2051413). We sincerely appreciate your confirmation, questions and advices of our work. Accordingly, we have supplied the corresponding response and revision based on the comments. We sincerely hope that our responses will fully address your concerns about our work.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Authors replied for all my queries. But I suggest to add to the table S1 results of this study for the best comparison and visibility.
Afterward this manuscript could be accepted
Author Response
Dear Reviewers,
Thank you again for your precious time to constructive comments on our manuscript titled “Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols” for Catalysts (Manuscript ID: catalysts-2051413). We sincerely appreciate your confirmation, questions and advices of our work. Accordingly, we have supplied the corresponding response and revision based on the comments. We sincerely hope that our responses will fully address your concerns about our work.
Author Response File: Author Response.pdf
Reviewer 2 Report
I have no further comments for the authors. I think the authors' answers are convincing enough for the article to be published.
Author Response
Dear Reviewers,
Thank you again for your precious time to constructive comments on our manuscript titled “Constructing Active Sites on Self-Supporting Ti3C2Tx (T = OH) Nanosheets for Enhanced Photocatalytic CO2 Reduction into Alcohols” for Catalysts (Manuscript ID: catalysts-2051413). We sincerely appreciate your confirmation, questions and advices of our work. Accordingly, we have supplied the corresponding response and revision based on the comments. We sincerely hope that our responses will fully address your concerns about our work.
