Photocatalytic Degradation of Ciprofloxacin by UV Light Using N-Doped TiO₂ in Suspension and Coated Forms

Round 1

Reviewer 1 Report

In the current manuscript, CIP was removed from simulated wastewater using photocatalytic process 14 (PCP) with suspension nano-TiO2 as catalysts. The catalyst was modified using the co-deposition 15 process for various loading by Nitrogen in various weight percent of Nitrogen (0, 4.3, 5, 5.7 wt.%) 16 to obtain N-TiO2 catalyst in order to enhance the CIP removal process. The nitrogen-loaded catalyst 17 N-TiO2 was characterized using Energy Dispersive X-ray (EDX), Scanning electron microscopy 18 (SEM), and Fourier transform infrared spectroscopy (FTIR). The performance of the net TiO2 catalyst 19 used in PCP process was examined under various operating conditions to study their effect on the 20 CIP removal process, such as the initial concentration of the CIP (6, 12, 18, 30 ppm), pH (3, 5, 7, 9), 21 flowrate (0.4, 0.8, 0.95, 1.5 L/min).

The manuscript needs urgent revision for being reconsidered in Catalysts journal, based on the following comments.

1. Title should be rewritten based on the modification type of TiO2. Illumination source should be included too.
2. The abstract should clearly highlight the essence of problem you addressed, the novelty of the work, since lots of publications have been released on N-TiO2 photocatalysts. Underscore the scientific value-added (not what are mentioned in the experimental section in details!) to your paper in your abstract. That would help a prospective reader of the abstract to decide if they wish to read the entire article.
3. The abstract is too long and weary.
4. I think nitrogen is doped into the bulk structure no loaded on the surface. Accordingly, change the keywords and whatever you stated in the content in regard with it.
5. A large number of novel photoactive materials have been published in the past years, should be addressed smoothly. For your reference, Please consider these one as examples:

-          https://www.sciencedirect.com/science/article/abs/pii/S0925838820333193

-          https://www.sciencedirect.com/science/article/abs/pii/S0926860X22003179

6. Subsection 2.2.2 should be edited considering comment 4.
7. The English of the manuscript should be improved.
8. The quality of figures is very poor. Fig 2 for instance; where are axis titles?? Texts are not clear.
9. SEM images; should be well addressed the presence of ambiguous segments on the surface of microparticles!
10. Fig 4, spectra is true! Look at the content in PDF version, legends are not clear. axis titles again!!! All figures must be well revised to improve the content. It is a mess.
11. Figures font style must be a unique type. Change everything accordingly.
12. How many times the experiments were repeated to evaluate the error bars? Should be clearly stated in the experimental section.
13. Captions for the figures of the photocatalytic results must clearly state the operating conditions during the test. Change everything accordingly.
14. A typical UV-vis spectrum of CIP during the photocatalytic removal under optimal conditions must be provided.
15. Please make sure your conclusions' section underscores the scientific value-added of your paper, and/or the applicability of your results. Highlight the novelty of your study. Clearly discuss what the previous studies that you are referring to are.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Sarah A. Abdulrahman et al. reported “Photocatalytic Degradation of Ciprofloxacin by Modified TiO₂ Nano-catalysts”. The present work is looking interesting and acceptable to publish in catalysts journal after the minor revision.

Comments and suggestions

1.      The title must be attractive for the readers. It’s very simple and not attractive.

2.      The abbreviation in the abstract is not good habit. Remove all the abbreviation from the abstract part.

3.      The introduction part need more improvement with updated references.

4.      What is mean by nano-TiO₂ catalyst? Although we all know that its size will be in nano. How you confirm its size? Although we need TEM for such type of analysis. How the nitrogen was confirmed that bond with TiO₂ surface?

5.      Mention the % purity of all the chemical in materials part.

6.      Where is EDS table for element composition. It should be included in the revised manuscript.

7.      Why the scale bar is different in SEM images it must be same because it is a comparison of two different sample. Please try to provide more SEM images for comparison. One SEM Image is not enough for suck kind of studies.

8.      The photocatalytic study was done at what sun? 1 sun, 2 sun or 3 sun?

9.      The FTIR data should be draw in Origin software. It’s not acceptable in the present form.

10.  Improve the English throughout the manuscript.

11.  Draw the mechanism of photocatalytic degradation.

12.  The following articles will be helpful to improve the introduction part of the present work.

https://doi.org/10.1016/j.jece.2021.105580, https://doi.org/10.1016/j.jece.2019.103291  https://doi.org/10.1021/acsaem.9b01530

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Thanks to the authors for inserting the comments well.

Acceptance is recommended.