Current Scenario of MXene-Based Nanomaterials for Wastewater Remediation: A Review

Round 1

Reviewer 1 Report

Dear Authors,

 

After familiarizing with the submitted review I found following issues.

 

1. English has to be improved. Typos like biodegration, missing linkers, comas etc.

2. MXene owns the hydrophilic nature incorporated with hydrophicity and active functional group on its surface extracts the adsorptive nature to tackle ionic/molecular species for environmental resolution - sentence like this has to be rewritten.

3. Furthermore, the morphology of MXene flakes structure was identified by some characterization method such transmission electron microscopy (TEM) and scanning electron microscopy (SEM) which displays nanotube-like structures. - I always though we have accordion-like multilayers and graphene-like MXene flakes.

4. In all the tables and description please write on what type of MXenes other people made their research. Multilayers - M-MXenes or single ones - S-MXenes. Similarly M-Ti3C2Tx / S-Ti3C2Tx.

5. Lines 152-159 and 178-184 are a repetition.

6. Part 1.3 is redundant.

7. Figure 5 should be removed. It shows fault results with unsuccessful execution of MXene formation protocol.  HCl-LiF should give monolayers, not multilayers. Do not cite bad research.

8. The review structure is also kinda reversed. As I understood, the wastewater remediation starts with polutants, adsorption of them over material, then all the photocatalysis catalysis processes i.e. Therefore, after the synthesis part, Enviromental application and adsorption should go first.

9. Also it is better for the reader, if all the mechanisms in general are described prior the actual application of MXenes, so 4.2 Photocatalysis mechanism -> 4.1. Photocatalysis.

10. I would totaly drop the toxicity and ecological power (btw what is the ecological power????)  unless you want to go into MXene cytotoxicity and biocompatybility studies. You mentioned surface chemistry, flake size, transition metals influence, but such research on human cell lines has been done -> please check A. Jastrzębska / B. Scheibe works.

11. You mention the Regeneration studies of MXene-based nanomaterials. However, there is no real info on MXenes environmental instability. MXenes in water =  time dependent decomposition toward transition metal oxides. And the Review is about wastewater remediation. Means MXenes in water. Therefore, this thing has to be included as well as info related how to potentialy stabilize material so it may work properly.

12. The instability problem is also a key factor in MXene application in photoelectrochemical processes. Where oxidized / defected MXenes with TiO2 layer exhibit i.e. higher charge separation of MXene-based photocatalyst. This is typical for all papers including MXene hydrothermal treatment. Therefore, the designation: MXene-based nanomaterials - is an excuse for placing all materials togather without putting an effort into checking cited papers - what is true or false.

Author Response

Please see the attachment. Thank you.

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors describe the “Current Scenario of MXene-Based Nanomaterials for Wastewater Remediation: A Review.”Well written.

Comments:

1.     Line:102, While using of  MXene in electrolytic solution it will be increase the Concentration Gradient? Explain the reason.

2.     Table;1 , Ti3AlC2 mass (g)  and Etching temp. (°C) is same Ref 19, Ref 27  , but What is the reason of Etching time (hr) is different , Recommend to author give the clarification.

3.     Throughout the manuscript, In  tables Should give the Ref is Like “Reference”.

4.     Figure 6 (a) /Figure 7 (a) images is it’s not clear. Check it.

5.     Authors should cite recent publications for the introduction. Should be more elaborative.

6.     A through grammatical check, Space, Commas (,), spelling mistakes must be performed for the entire manuscript.

Author Response

Please see the attachment. Thank you.

Author Response File: Author Response.pdf

Reviewer 3 Report

This manuscript reports the MXene-based nanocomposites for wastewater remediation and water-splitting applications. This manuscript was systematic and well-organized. After careful consideration, I believed it is suitable for publication in this journal. However, We found several mistakes (typo/grammatical errors) and also give a proper space between each column in the tables. Please correct the errors the throughout the manuscript to enhance the quality of the manuscript.

Author Response

Please see the attachment. Thank you.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Good work.