Oxygen-Vacancy-Rich Fe@Fe3O4 Boosting Fenton Chemistry
and Weidong Kan 5Round 1
Reviewer 1 Report
More detailed characterization of the core-shell catalyst system is needed. Very important reduction rates are not really observed and it is important to be able to elucidate the influence of Fe0 during Fenton reduction reactions. It is considered the importance of the effect combined of iron catalysts with oxygen vacancy and the redox properties of the catalysts should be analyzed in more depth
Author Response
Please kindly see the attached file.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This manuscript focuses on the synthesis of Fe@Fe3O4 catalysts for Fenton Chemistry. The catalysts were thoroughly characterized with XRD, TEM, XPS, and so on. Various details were investigated for the catalytic performance. However, it is very confusing, and some results are not accurate and conflict with each other. Overall, the manuscript must be revised properly. Here are some suggestions.
Why did author use (220) rather than (311) to calculate the particle size of Fe3O4?
In HRTEM fig.6. there is a clear black gap for Fe2O3-S-P, but a smooth interface for Fe2O3-N-E.
In 2.3.1 section, The reduction was carried out at 350. So the review doubt the correction of the analysis to link the activity to the appearance of Fe0, which is occurred in the range of 473~673. Beside, the H2O2 was added into solution, so the iron species in reaction solution may not the same as the one after reduction treatment. Then the analysis between activity and share of Ov and Fe2+ may not reflect the real situation of catalysts.
In 2.3.2 section, the author mentioned that” Fe2O3-S-P reduced in H2 at varying temperatures from 300-450 261 oC was conducted. The PXRD results confirmed that Fe2O3 was the major phase after 300 262 oC reduction (Figure 11). After reduction at 350 oC, Fe0 was the major phase with the co-263 existence of Fe3O4. After further increasing the temperature to 450 oC, Fe0 was the only 264 phase”Such results conflict with the in-situ XRD analysis.
For the exposure to air analysis, the more excise details should be provided, such as: exposure time, temperature. These factors may affect the depth of Fe2O3 layer. Furthermore, all measurement details related to exposure to air should be mentioned, since the catalysts are so sensitive to air.
In addition, the review think the in-situ xrd or XPS for the oxidation of catalysts by air may be interesting and meaningful.
Minor editing of English language required.
Author Response
Please kindly see the attached file.
Reviewer 3 Report
In this work iron oxides of four different model systems are designed through a conventional precipitation method plus H2 reduction treatment. These systems feature Fe@Fe3O4 with abundant oxygen vacancy, Fe0 and Fe3O4 particles with interface structures, and Fe3O4-dominated nanoparticles of different sizes. These materials are applied in the decomposition of methyl orange as a model reaction to assess the Fenton chemistry.
However, some critical issues remain to be solved and a thorough revision was needed:
1. The “introduction” and “results and discussion” sections of the manuscript can be strengthened and supported with some papers related to the literature and cited (optional for authors): J. Mol. Struct. 1263 (2022) 133160.
2. The advantages and disadvantages of iron oxides should be investigated.
3. On what basis the authors chose this particular methyl orange. Did they check for others? Cite the following reference: Appl. Organomet. Chem. 36 (2023) e7113.
4. The ion leaching during the decomposition process should be indicated.
5. The authors should make reusability of the iron oxides nanoparticles and comparison with literature.
6. The manuscript needs thorough revision to improve the text quality and readability of the work.
In this work iron oxides of four different model systems are designed through a conventional precipitation method plus H2 reduction treatment. These systems feature Fe@Fe3O4 with abundant oxygen vacancy, Fe0 and Fe3O4 particles with interface structures, and Fe3O4-dominated nanoparticles of different sizes. These materials are applied in the decomposition of methyl orange as a model reaction to assess the Fenton chemistry.
However, some critical issues remain to be solved and a thorough revision was needed:
1. The “introduction” and “results and discussion” sections of the manuscript can be strengthened and supported with some papers related to the literature and cited (optional for authors): J. Mol. Struct. 1263 (2022) 133160.
2. The advantages and disadvantages of iron oxides should be investigated.
3. On what basis the authors chose this particular methyl orange. Did they check for others? Cite the following reference: Appl. Organomet. Chem. 36 (2023) e7113.
4. The ion leaching during the decomposition process should be indicated.
5. The authors should make reusability of the iron oxides nanoparticles and comparison with literature.
6. The manuscript needs thorough revision to improve the text quality and readability of the work.
Author Response
Please kindly see the attached file.
Author Response File: Author Response.docx
Round 2
Reviewer 2 Report
The manuscript has been correctted properly according the comments.
