High-Efficiency Photon-Capturing Capability of Two-Dimensional SnS Nanosheets for Photoelectrochemical Cells

Round 1

Reviewer 1 Report

The manuscript entitled “High-Efficiency Photon-Capturing Capability of Two-Dimensional SnS Nanosheets for Photoelectrochemical Cells” by  Xiaoguang Huang, Heechul Woo, Peinian Wu, Myungkwan Song and Jin Woo Choiby  is very interesting and, generally speaking, well prepared and written. The authors prepared, studied and discussed 2D SnS in relation to the construction and using them in photoelectrochemical cells. The manuscript is generally well prepared, nevertheless I would like to  suggest a few possible corrections:

• In the Introduction, I do not know what the Authors mean by “..and a few carrier transport distances for water splitting.” Do you mean short distance?
• Figure 2a shows XRD patterns of S1, S2, S3 samples. At the first glance, I cannot see much difference between the patterns of S2 and S3. Therefore, I do not understand the sentence “The intensity of the (111) peak was the strongest in S2; however, the (040) was evident in S3.” What seems to me is: in both patterns (040) is the strongest, whereas in S2 (111) is slightly stronger than in S3. Please, explain that.
• The sentences: “First, this might be due to the film density. When the sheets are denser, the lattice dimensions are distinct from those of the chemically identical materials. When the deposition temperature is increased, the SnS lattice parameters may increase slightly.” should be modified. First of all, unit cell parameters do not depend on density. They might depend on the crystallite size, however in the case of the SnS studied in the manuscript, the crystallite seem too large for that. The unit cell parameters usually depend on the point defect content, so that it may be influenced by temperature, atmosphere or some other details of synthesis. Nevertheless, the Authors did not give the details of the procedure for unit cell determination which they used, but in view of the xrd patterns shown in Fig. 2a, I suppose that the accuracy of unit cell parameters determination is not high.
• The sentence “With the promise of converting sunlight into photocurrent, the optical band gap should obtain electrons to perform work after the absorption of sunlight.” seems to be awkwardly written. I do not think, the band gap “obtains electrons to perform work”.
• The terms in equation (1) should be defined/described.
• The fragment “It is undesirably dense in the S1 and S2 films; these imperfections in the grain boundary can inhibit electrical conduction. A desirable dense surface was generated in the S3 film..” require some explanation/corrections. I do not understand that S1 and S2 are undesirably dense while S3 has desirable dense surface. I assume, S3 is rather not dense.
• In Experimental: POCVD should be PECVD
• In the sentence: “..which exceeded that reported in previous studies on SnS nanosheets.” the reference/references are necessary.

Author Response

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Author Response File: Author Response.DOCX

Reviewer 2 Report

The article itself is well written, although a) it presents some less rigorous aspects in the interpretation of certain results. The authors carried out a literature review that allows explaining the context of the present work; b) For the article to be accepted, it is necessary to clarify and improve some aspects.

1) the XPS is missing in the abstract;

2) it seems strange to me that the material and methods section is at the end. It is best to move to point 2 (after the introduction). Reorder everything according to this change;

3) Figure 3-): there are two peaks that are not assigned. Please make the assignment because one of them has a high intensity. The position appears to be oxygen... and the precursor materials are hydrated. Could oxygen be considered an impurity in this case? Is possible obtain FTIR to check?

4) Figure 5: Which of the lines corresponds to the dark current and to the ligth current?

5) Figure 7: write Raman instead of Ramam. the discussion held on the basis of this figure is insufficient. Please provide more information. The two peaks must be assigned.

Author Response

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Author Response File: Author Response.DOCX

Round 2

Reviewer 2 Report

The authors have addressed all the comments and suggestions I made in the first review. The quality of the article has significantly improved. I don’t have further suggestions. The paper is now acceptable for publication.