Trimesoyl Chloride-Melamine Copolymer-TiO₂ Nanocomposites as High-Performance Visible-Light Photocatalysts for Volatile Organic Compound Degradation

Round 1

Reviewer 1 Report

Wang et al. describe here the synthesis of trimesoyl chloride-melamine grafted TiO2 nanoparticles for the photocatalytic decomposition of Benzene. Overall, the research is interesting and appropriate to the journal. However, some more work is needed to address some of the important questions and below are my comments-

• In the introduction, “adsorption” need to be replaced by “absorption” for the description of visible light activity,
• The IR spectra for the material at 3000-3500 cm-1 region is not clear. I am assuming these region will be dominated by surface hydroxyl and water. I would expect significant change due to the polymer binding to the TiO2 through the surface –OH groups in that region.
• Is it possible to monitor the changes in IR under gaseous benzene atmosphere?
• They mentioned, after the polymer grafting, the particle size decreased from 10 nm to 7 nm due to the amide bonds. These values seem more similar than different to me. What is the error limit of the TEM particle size distribution? Please show the histogram. Do they have any other evidence regarding the decrease in particle size after amide bond formation?
• The major problem is there is no clear explanation of the mechanism of the catalysis. They hypothesize the faster rate could be due to trap sites. Is there any evidence?
• Is it possible to observe that the composite material can uptake any benzene by isotherm?

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

This work deals with the preparation and characterization of a chlorine-melamine-TiO2 catalyst. The authors used the prepared catalyst for the destruction of benzene under visible irradiation. The novelty is moderate. The subject of the work belongs to the catalyst. However, the work needs modifications before publication.

The authors use Taguchi design to see the importance of each parameter for the synthesis of the material. Why did they not based on these results to further optimize the synthesis (for example, towards a higher hydrothermal temperature?

Table 1 the fifth row (factor 4) must be time and not temperature

There is no equation derived from the factorial design?

The authors must perform actinometry to provide us the real power expressed as photos. Time inside the reactor. The nominal power has no meaning

2.6 the authors attributed the enhanced efficiency here only to shift of the absorbance at the visible spectrum are sure that is, is the only and (main) reason?

It would be interesting to see some results of the characterization AFTER reuse, for example, after five cycles. Kinetics does not say the whole truth sometimes.

 

 

 

 

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

In this paper, the authors reported the preparation of trimesoyl chloride-melamine copolymer (TMP)-TiO₂ nanocomposites for volatile organic compound degradation.

They found the optimal condition for the preparation of the nanocomposite applying the Taguchi L9 (3⁴) orthogonal array design, and reported that the obtained TMP-TiO₂s are efficient visible-light photocatalysts for gas-phase benzene degradation.

The characterization of TMP-TiO₂ nanocomposite and photocatalytic activity tests were performed suitably by using various experimental methods such as TEM, SEM, FT-IR, XPS and benzene gas photocatalytic reactor designed in their laboratory.

Although I think that this paper should be published, there are some comments as follows.

 

Comments

1. Table 1 should be correct. (For example, column fifth)
2. 1

SN → S/N

3. Line 100,104,108,110

4a, 4b, 4c, 4d → 3a, 3b, 3c, 3d

4. 3

The Fig. c should be exchanged with Fig. d.

5. 5e inset

The figure is not clear.

6. Line 215, 216, 274

CuCl2, TiO2 → CuCl₂, TiO₂

7. Which factor is the most important key one to enhance the photocatalytic activity of TMP-TiO₂ nanocomposites, in the following new properties of the nanocomposites, interparticle porosity, abundant active site, decrease in TiO₂ nanoparticle size, mixed anatase-rutile, photo-absorption in visible-light region, and decrease in the band gap?
8. Did you measure the photocatalytic activity of unmodified TiO₂ and TMP-TiO₂?

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors appropriately addressed the comments from the reviewers. The manuscript is now OK to accept.

Author Response

We appreciate your time and efforts for this manuscript.

Reviewer 2 Report

The authors revised their work according to the reviewers suggestion. The work now is suitable for publication

Author Response

We appreciate your time and efforts for this manuscript.