Photocatalytic Degradation of Organic and Inorganic Pollutants to Harmless End Products: Assessment of Practical Application Potential for Water and Air Cleaning

Round 1

Reviewer 1 Report

In this manuscript, the authors reviewed advances of photocatalytic degradation of organic and inorganic pollutants. However, I do not recommend the publication of this work at this stage for the following reasons:

1. The title was a too general topic, which could be more focused considering your manuscript contents. The keyword of “mechanism” should be replaced.

2. The light irradiation was not clearly demonstrated, what about visible light and UV light, etc.? The diversity and mechanisms should be added clearly.

3. I am confused why this review should be divided into these main sections. The relations and significance of the contents should be described in detail in the introduction.

4. Schematic illustration can be created in the introduction to demonstrate the manuscript structure. Besides, composite figures are also needed in section 2.1-2.2.

5. The contents of all the figures are too simple. As a comprehensive review, the authors are suggested to expand each figure into enriched combinations, which could contain various typical examples. Some simple figures can also be merged into one.

6. The authors should add one special section to propose perspectives or challenges for future researches in this field, and a corresponding schematic figure need to be created.

7. The review can be revised with a more clear structure. The headings and also some subheadings can be revised for better demonstration and understanding.

8. The references should be checked with the right formats.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Reviewer 2 Report

This work summarizes the recent advances reported for photomineralization of various recalcitrant contaminants from indoor air and water, focusing on (i) newly developed photocatalytic materials, (ii) reaction mechanism, (iii) identification and quantification of degradation intermediates, and (iv) implication of ROS in degradation pathways. The photocatalytic abatement of aqueous inorganic nitrogen-based pollutants (e.g. NO3–, NH4+). In this case the efficiency of the photocatalyst is assessed from the decrease in ions concentration containing nitrogen occurring via elimination of gaseous products are briefly discussed. However, the overall impression for this review study is lack of novelty and has not disclosed new results/findings. There are many similar review journals/articles have been well reported especially on  the “photocatalytic degradation of organic and inorganic pollutants to harmless end products”. The summary results are commonplace and easy to be expected. Therefore, I cannot recommend publication of this paper under the present situation. This work should be seriously revised and needs more detailed and careful investigations. The following comments should be addressed for the improvement of this manuscript.

1.      1-The authors should emphasize what is the novelty of their summary works/investigations as compared to previous publications. The current scope of review is broad and the summary development or focus area need to be further improved.

2.     2- The authors should provide a fair and complete literature review about the previous works about “newly developed photocatalytic materials” as compared to conventional type materials.

3.    3- The authors are suggested to carry out detailed investigations on “photocatalytic abatement of aqueous inorganic nitrogen-based pollutants (e.g. NO3–, NH4+)” with recent development of promising photocatalysts in improving the photocatalysis reactions.

4.      4- All the figures captured from other sources need to be cited and provide the permission license agreement accordingly.

5.      5- The future direction, commercialization aspects and perspectives for photomineralization of various recalcitrant contaminants from indoor air and water as compared to the current / conventional system need to be discussed in detail before the conclusion section.

6.    6- The carefully English correction is necessary for the whole manuscript. There are several grammatical mistakes and errors were found throughout the manuscript. Please check and revise accordingly.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The article entitled "Photocatalytic degradation of organic and inorganic pollutants to harmless end products″ discusses a review of recent advances in photocatalysis, a method for removing harmful chemicals from the environment using solar light and catalytic materials. The review focuses on the challenges facing photocatalysis, such as the formation of harmful intermediate products, low reaction rates, limited catalyst stability, and difficult catalyst recovery. The review also covers the use of photocatalysis for the removal of pollutants from indoor air and water, as well as the abatement of aqueous inorganic nitrogen-based pollutants, such as NO3- and NH4+. The efficiency of photocatalysis is evaluated by measuring the decrease in the concentration of nitrogen-containing ions and the elimination of gaseous products.

This review is suitable for publication after some major revision.

Concerning our main remarks, corrections and suggestions about your work are:

1.Can you provide more information about the specific pollutants and contaminants that your research focuses on?

2.How does the efficiency of heterogeneous photocatalysis compare to other advanced oxidation processes for environmental remediation?

3.Can you explain the mechanisms of degradation reactions in more detail?

4.Can you provide examples of other methods that can be used in conjunction with photocatalysis for the treatment of larger organic molecules?

5.Can you discuss any limitations or challenges of photocatalytic technologies for environmental remediation?

6.How can photocatalytic technologies be made more cost-effective and practical for large-scale implementation?

7.Can you give some examples of the areas or industries where these photocatalytic technologies have been implemented or are currently being implemented?

8.Can you discuss any recent developments in the field of photocatalytic technology?

9.How does the presence of oxygen affect the photo dissociation rate of methanol on photocatalyst surface?

10.How does the gap energy, surface area and particle size of the photocatalyst affect the photocatalytic efficiency of oraganic pollutant mineralization?

11. How does the concentration of pollutants and the dosage of photocatalyst affect the efficiency of photocatalytic removal of VOCs from water?

12. Manuscripts should refer to and cite as much as possible from the last years. Some high-quality literatures about photocatalyst and sustainability of water in recent years can be referenced and cited, such as Arabian Journal for Science and Engineering 1-11 (2021) https://doi.org/10.1007/s13369-022-06899-y; Journal of Desalination and Water Treatment 194 (2020) 439-449.

Author Response

Please see the attachment

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I'm satisfied with your responses. Good luck.

Reviewer 2 Report

In overall, this manuscript was technically well revised. This revised manuscript meets the criteria of Catalysts. Therefore, in my opinion, the revised manuscript can be accepted for publication.

Reviewer 3 Report

No comments