Double Complex Salt [Co(NH3)6][Fe(CN)6] Plasma Treatment
, Oleg Golubev 2, Vladimir Vinogradov 1, Sergei Svidersky 2, Alena Grabchak 2, Diana Manukovskaya 1,*, Mihail Ivantsov 2 and Mayya Kulikova 2Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThis manuscript proposes a novel method for preparing CoFe₂O₄ spinel nanoparticles via plasma treatment of double complex salt (DCS) [Co(NH₃)₆][Fe(CN)₆]. The topic is closely related to the fields of materials science and green synthesis, and the research also demonstrates potential environmental benefits. However, there are several shortcomings in the manuscript that need to be addressed before considering publication.
1.The authors claim that the plasma-assisted method is more environmentally friendly and efficient than traditional methods, but no direct comparison between this method and traditional synthesis routes is provided. Conducting a comparative analysis with at least one traditional method in terms of energy consumption, reaction time, particle size, and phase purity would help enhance the innovativeness and influence of this research.
2.All images require higher clarity. The images are drawn too roughly. It is recommended to improve the quality of the figures, refine the annotations, and enhance readability.
3.In this study, the results under each experimental condition are derived from a single experiment. To verify the reproducibility of the results of mass loss, phase composition, and grain size measurements, repeated experimental data and error bars are indispensable.
4.The structural and chemical evolution of the double complex salt (DCS) during plasma treatment has not been fully characterized. It is recommended to supplement X-ray photoelectron spectroscopy (XPS) analysis to determine the oxidation states of cobalt (Co) and iron (Fe) as well as the degree of ligand removal.
5.It is suggested to supplement transmission electron microscopy (TEM) to directly observe the morphology and dispersibility of the nanoparticles. Relying solely on the coherent scattering region (CSR) data from XRD to draw conclusions about particle size cannot fully confirm the nanostructural characteristics of the product.
Author Response
Reviewer 1
This manuscript proposes a novel method for preparing CoFe₂O₄ spinel nanoparticles via plasma treatment of double complex salt (DCS) [Co(NH₃)₆][Fe(CN)₆]. The topic is closely related to the fields of materials science and green synthesis, and the research also demonstrates potential environmental benefits. However, there are several shortcomings in the manuscript that need to be addressed before considering publication.
Answer:
Dear Reviewer!
We are deeply grateful for your attention and time. We have tried to answer all your questions. Working with the article in the process of answering significantly improved the text and clarity of presentation. Please note: Changes made in accordance with the comments of the respected reviewers are written in red text. Changes to the English language are written in blue font.
Reviewer 1
1.The authors claim that the plasma-assisted method is more environmentally friendly and efficient than traditional methods, but no direct comparison between this method and traditional synthesis routes is provided. Conducting a comparative analysis with at least one traditional method in terms of energy consumption, reaction time, particle size, and phase purity would help enhance the innovativeness and influence of this research.
Answer:
Thanks for your valuable comment. Plasma treatment of the solid materials is considered as more energy efficient method compared to thermal destruction, as the active plasma particles readily react with the solid material and convert it into the product without any external heating. The duration of the plasma impact on the material is much lower compared to the conventional thermal processes. Ecological aspect is much more complicated at the current stage, but in the future, the electricity for plasma generation can be obtained from the renewable sources. As for the application of plasma for the treatment of the DCS, the processing time was significantly reduced and the obtaining spinels from the treated samples became possible.
Reviewer 1
2.All images require higher clarity. The images are drawn too roughly. It is recommended to improve the quality of the figures, refine the annotations, and enhance readability.
Answer:
Thanks for your comment. The quality of the figures was increased
Reviewer 1
3.In this study, the results under each experimental condition are derived from a single experiment. To verify the reproducibility of the results of mass loss, phase composition, and grain size measurements, repeated experimental data and error bars are indispensable.
Answer:
Thank you for the valuable comment. Indeed, the reproducibility of the plasma treatment was taken into the consideration. In order to exclude the possible fluctuations, each experiment was conducted for three repeatable times. It was concluded that the mass of the treated DCS sample was similar in each series of experiment. Nevertheless, we added the error of the mass measurement in the Results and Discussion section. Data on the errors in determining the CSR have been added to Figure 12.
Reviewer 1
4.The structural and chemical evolution of the double complex salt (DCS) during plasma treatment has not been fully characterized. It is recommended to supplement X-ray photoelectron spectroscopy (XPS) analysis to determine the oxidation states of cobalt (Co) and iron (Fe) as well as the degree of ligand removal.
Answer:
Elemental analysis showed the absence of nitrogen and hydrogen in the composition of sample A-6-1000, therefore, coordinated ammonia was completely removed as a result of plasma+thermolysis treatment. The carbon content is 0.9±0.1 wt.%, which indicates that 4.7% of the original carbon content, which is part of the cyano groups, remained in the calcination residue in the DCS. XPS analysis was added to the Manuscript text.
Reviewer 1
5.It is suggested to supplement transmission electron microscopy (TEM) to directly observe the morphology and dispersibility of the nanoparticles. Relying solely on the coherent scattering region (CSR) data from XRD to draw conclusions about particle size cannot fully confirm the nanostructural characteristics of the product.
Answer:
We have added SEM images analyses to the Manuscript. We have found that CSR are 40 nm, while particles are 200-1000 nm. The discussion is given in the text.
Reviewer 2 Report
Comments and Suggestions for AuthorsThis paper describes the use of plasma discharges to modify the double compolex slat to make a spinel.
The English in the manuscript really needs substantial work.
The Introduction is far too long for the level of work done. The Introduction does not need to describe everything that metal containing nanoparticles can do. Focus only on what this type of spinel nanoparticle can do or os useful for. Most of the rest of the Introduction is not needed. For example, there is no discussion of catalysis in the paper nor is the quality of the spinel nanoparticles that are being synthesized in this work tested for anything. Shorten the entire Introduction by close to 90%
The figure in the Supporting Information might as well be in the text as it is the only supporting material and this makes no sense.
The figures need some work. The Lissajous curve in figure 2 can be improved.
The traces in Figures 7, 8, and 10 are too faint to be readable and need to be made darker.
Figure 11 needs error bars. Can a curve be fit to the data in Figure 11? It looks like a modified S-shaped curve might work. Why is there a variation of the particle size with temperature? Why are larger particles formed at higher temperatures?
The authors note environmentally friendly process in the abstract but do not discuss this or demonstrate it in the manuscript.
There needs to be more discussion of the quality of the spinel that is formed.
Comments on the Quality of English LanguageNeeds major work
Author Response
Reviewer 2
This paper describes the use of plasma discharges to modify the double compolex slat to make a spinel.
Answer:
We are deeply grateful for your feedback. We have tried to answer all your questions. Working with the article while answering significantly improved the text and clarity of presentation. Please note: Changes made in accordance with the comments of the esteemed reviewers are written in red text. Changes to the English language are written in blue font.
Reviewer 2
The English in the manuscript really needs substantial work.
Answer:
Thank you for your attention to the text of our manuscript. We have asked an editor with extensive experience in Academic English to review the manuscript. Changes to the English language are written in blue font.
Reviewer 2
The Introduction is far too long for the level of work done. The Introduction does not need to describe everything that metal containing nanoparticles can do. Focus only on what this type of spinel nanoparticle can do or os useful for. Most of the rest of the Introduction is not needed. For example, there is no discussion of catalysis in the paper nor is the quality of the spinel nanoparticles that are being synthesized in this work tested for anything. Shorten the entire Introduction by close to 90%
Answer:
Thank you for this remark! We have shortened the introduction somewhat according to your remark. Let us note that almost all (except two) of the discussed DKS and the catalysts obtained from them are directly related to the topic of our study. They all contain Co and/or Fe, as do our DKS. We believe that it is important and necessary to describe them in order to show the relevance of our study and our awareness of the field of similar scientific work in modern science.
Reviewer 2
The figure in the Supporting Information might as well be in the text as it is the only supporting material and this makes no sense.
Answer:
We thank you especially for this comment. We have done as you have recommended.
Reviewer 2
The figures need some work. The Lissajous curve in figure 2 can be improved.
The traces in Figures 7, 8, and 10 are too faint to be readable and need to be made darker. Answer:
The figures quality has been improved.
Reviewer 2
Figure 11 needs error bars. Can a curve be fit to the data in Figure 11? It looks like a modified S-shaped curve might work. Why is there a variation of the particle size with temperature? Why are larger particles formed at higher temperatures?
Answer:
We have improved the images. Errors + approximation graph have been added to Figure 11 (now Figure 12). The increase in particle size with increasing processing temperature occurs due to particle agglomeration, which leads to the formation of larger particles.
Reviewer 2
The authors note environmentally friendly process in the abstract but do not discuss this or demonstrate it in the manuscript.
Answer:
You are absolutely wright. We have rewritten the abstract.
Reviewer 2
There needs to be more discussion of the quality of the spinel that is formed.
Answer:
We have added some experimental results that have deepened our knowledge of the obtained spinels.
Round 2
Reviewer 2 Report
Comments and Suggestions for AuthorsThe paper is substantially improved. The new Figure 13 has many issues with it. The text is too small to read and the lines are too faint. After fixing this figure in all of its parts, the paper is acceptable.
