Photocatalytic Activity and Reusability of F, Sm3+ Co-Doped TiO2/MWCNTs Hybrid Heterostructure for Efficient Photocatalytic Degradation of Brilliant Black Bis-Azo Dye
Round 1
Reviewer 1 Report
Manuscript deals with the Photocatalytic Activity and Reusability of F, Sm3+ Co-Doped 2 TiO2/MWCNTs Hybrid Heterostructure for Efficient Photocata- 3 lytic Degradation of Brilliant Black Bis-Azo Dye. But publication point of view some modification is necessary.
1) There are a few grammatical mistakes. Please check the manuscript for grammar and English.
2) What is the novelty of the present work? Rewrite it at the end of the introduction section.
3) Compare your photocatalytic results with other researchers' work and present them in table form.
4) In Fig. 4 add error bars.
5) Add XPS study of prepared material.
6) Recycling experiments should be provided, and XRD or XPS should characterize F, Sm3+ Co-Doped 2 TiO2/MWCNTs composites after photocatalytic reaction to check the stability of the catalyst.
7) To confirm mineralization add a TOC study.
8) The photocatalytic reaction mechanism should be further explored by the necessary experiments, such as the trapping experiments for hydroxide radical and the ESR experiments for the O2·
9) To enrich the manuscript add some references
i) Ultrasonics sonochemistry 61, (2020) 104849
ii) Catalysts 12 (10), (2022) 1290
10) Calculate the conduction and valence band potentials of the prepared materials
Author Response
The authors would like to thank and appreciate the reviewers for devoting time to adding value through critical evaluation of the manuscript. All the reviewers’ comments make valuable contributions towards the quality of the manuscript and have been considered and responded to in Tables 1 and 2. In addition, the revisions have been factored in the final manuscript submission as highlighted in the Manuscript with track changes.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript catalysts-2105929, entitled “Photocatalytic Activity and Reusability of F, Sm3+ Co-Doped TiO2/MWCNTs Hybrid Heterostructure for Efficient Photocatalytic Degradation of Brilliant Black Bis-Azo Dye”. In this article, the author synthesized Fluorine-Sm3+ co-doped TiO2 (FST3) photocatalysts and photocatalysts were evaluated for photocatalytic degradation of Brilliant Black (BN) bis-azo dye in aqueous solution under simulated solar irradiation. This is a sustainable method for wastewater treatment with the potential to reduce both operating and disposal costs. A comparison of reusability between pure TiO2 and FST3/C1 showed 33.4% and 7% drop-in photocatalytic activity, respectively, after 5 cycles of use, 536 attributed to photocatalyst recovery after use. Their presentation on paper writing was not so exciting. But the topic is interesting for the referee. Therefore, I recommend publication only after minor revisions.
1) The abstract is not impressive in this paper. The author needs to change the abstract for better understanding.
2) Page No:3, line 109,111 and 112; Needs to remove space in between numbers (3 200-3 600, 1 500 and 1 300).
3) Figure 1 (a); the FTIR is showing a high percentage of moisture (according to O-H stretch peak). So, Is the results in this paper with moisture? If yes, the author needs to clarify the effect of moisture on your results.
4) Figure 1: the author needs to represent all the figures whose peak is corresponding to compounds (like Figure 1(d)).
5) The author needs to include a good image of Figure 2(b).
6) Page No: 9; In Discussion 3.1: the author needs to show/include Brilliant Black BN azo dye structure.
7) Figure 4: the author needs to include good quality figures.
8) Page 9; the author explained proposed mechanism for photodegradation. Figure 5 shows, the LUMO of MWCNT is lower than the CB of TiO2. Explain the possible mechanism. Is it possible, when exited MWCNT to transfer electrons to CB of TiO2 (according to Figure 5)?
Author Response
The authors would like to thank and appreciate the reviewers for devoting time to adding value through critical evaluation of the manuscript. All the reviewers’ comments make valuable contributions towards the quality of the manuscript and have been considered and responded to in Tables 1 and 2. In addition, the revisions have been factored in the final manuscript submission as highlighted in the Manuscript with track changes.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
The revision made by the author is satisfactory, and the present form of the manuscript should be accepted.
