In Situ Growth of NiSe2-MoSe2 Heterostructures on Graphene Nanosheets as High-Performance Electrocatalyst for Hydrogen Evolution Reaction
Round 1
Reviewer 1 Report
This paper presents the synthesis of NiSe-MoSe hybrid materials supported on reduced graphene. There are other papers in this field that they mentioned in the intro but a more detailed description of those reports and how this investigation builds on their work would be helpful to differentiate it from the previous reports. The data looks pretty good but I have some major concerns about the interpretation of their data and some missing information.
In the experimental, they put in a 1:1 ratio of Mo and Ni but they never report the final composition.
I also wonder if they can control the composition and if it makes any difference in catalytic results.
The xrd data only shows NiSe2 so I wonder where the Mo is and if is is doping the NiSe or simply amorphous. A lattice constant comparison of their product with NiSe2 could detect doping of the NiSe with Mo vs small amorphous nanoparticle of MoSe that are phase separated.
The raman data is also noisy, can they get a stronger signal and compare the peak positions of the pure phases to the composite materials to see if there are any shifts in the vibrations.
The XPS data would be easier to visualize if it was in a table. Peak positions, amounts etc for the pure and composite materials.
The elemental mapping in figure 4 e-h does doesn’t appear to have a corresponding image.
The did not report particle size of either phase or the surface area of these samples.
Figure 7 doesn’t really add much to the paper. It looks more like a table of contents image and could be removed from the text.
Author Response
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Reviewer 2 Report
In this work, Dai et al. have reported a NiSe2/MoSe2 heterostructure anchored on graphene nanosheets synthesized via a facile hydrothermal synthesis route. They have performed detailed material characterization and electrochemical evaluation of the material and compared it to baseline materials. Overall, the manuscript is well written in detail. Hence, I recommend the acceptance of this work.
Minor comment:
The manuscript should be checked for English language and grammatical errors, for instance: line 55 “To such these issues”. Also, some sentences are incomplete, for instance: In line 52 “decompose water molecules to produce”
Author Response
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Reviewer 3 Report
The work presented in the manuscript is a routine study. Already more than a thousand papers are available for metal selenide-hetero junction. This paper does add anything new in the field of materials design or the mechanism of water splitting. The activity of the catalyst is also moderate.
Although self-citation is low, irrelevant papers from two different labs are over-cited.
Author Response
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Round 2
Reviewer 1 Report
The authors have addressed all of my previous concerns and the resulting manuscript is acceptable for publication.
Author Response
Thank you for your comments
Reviewer 3 Report
(i) I do not find any improvement in the revised manuscript. The introduction part cannot justify the importance of the work. The activity of the catalyst is extremely poor compared to the literature reports. The authors have tabulated selected data in Table S2 to show the activity of the catalyst is better than in the previous reports.
(ii) Few sentences are difficult to understand (highlighted in yellow in the attached file). In fact, there is no meaning.
(iii) The XPS is completely misinterpreted. The presence of Ni2+ is obvious. It should be rewritten.
(iv) Why does heterojunction improve the HER activity?
(v) It is not clear why the authors have used the term in situ. I do not find any in situ methods.
(vi) Why 2D peaks are missing in the Raman spectra?
(vii) Why Mo is in a 6+ oxidation state?
(viii) The reference section does not include the pioneering works of the different labs around the world.
(ix) What is the zoom-in image?
(x) Chemical formulas are wrong.
(xi) Grammatical correction is required.
Author Response
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Author Response File: Author Response.pdf
Round 3
Reviewer 3 Report
There is no modification in the manuscript. It is exactly the same manuscript originally submitted. Only 4 sentences have been modified. Completely rewriting the manuscript is required in the light of present studies. Although the authors demanded that the catalyst is new, the catalyst system is multiple time explored. At the same time, hydrothermal synthesis is also well known for the synthesis of MSex-MoSey types catalysts. Therefore, I cannot recommend the manuscript for publication in its current form.
