Preparation of Fe₃O₄/NiO Nanomaterials by Electrodeposition and Their Adsorption Performance for Fluoride Ions

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The manuscript describes the preparation of coatings based on NiO nanomaterial modified with Fe2O3 by electrodeposition for applications in the adsorption of Fluorine ions. The work is interesting and also reports the investigation of the effect of the Ni:Fe ratio on the structural, phase composition, and surface morphology of the coating nanomaterials. The authors showed a correlation between iron oxide content with the adsorption properties of the materials. However, there are some important points that need to be corrected and addressed in the revision. In general, the authors claim the preparation of "magnetic" materials, but the magnetization measurements were not carried out for them. Moreover, the authors need to provide data and discussion about the results obtained for the isolated NiO and Fe2O3 materials, including structural characterizations, morphological characteristics, and application as adsorbents for fluorine ions, aiming at improving the scientific soundness of the present work. I am certain that the manuscript will gain in quality if the authors address all the points raised in the revision. 

The authors can find all the comments and questions in the attached file.

Comments for author File: Comments.pdf

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Minor corrections required.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript describes an adsorbent nanomaterial for fluoride ions. According to my opinion this is a nice work but corrections are needed before acceptance.

In Page 1, line 29 write fluoride instead of fluorine.

What do the abbreviations HFM and RTC mean?

I advise to write "stirring speed" instead of "mixer speed" in Table 2. Why was set even that value in it?

Please make clear what material was used as adsorbent throughout the experiments as in 2.3 magnetic magnesium oxide is mentioned. The aim of work is introducing magnetic NiO/magnetite nanomaterial.

On the other hand it should be clarified what method was used to measure the fluoride ion concentration, ionselective electrode or ICP-OES? If both of them, which was applied when?

Also in 2.3 "amount of metal ion" is written, my opinion is that it is fluoride ion or was an other ion studied as adsorbing specie?

In 3.6 what material was formed as NiF is incorrect, was it possible that exchange with hidroxide ions occurred in Ni(OH)₂?

Comments on the Quality of English Language

Basically English is good but at some places mistakes are found.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors, 

Great work! I am happy with the improvement of the work. The new version of the manuscript is now suitable for publication.

Author Response

Dear Prof.,

Thank you for your useful comments.

Have a good day!

Dr. Hongbin Zhang

Reviewer 2 Report

Comments and Suggestions for Authors

Some of my previous comments still need to be addressed. please see the attachment.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

Some minor corrections are needed.

Author Response

Please see the attachment.

Author Response File: Author Response.doc