Porphyrins Acting as Photosensitizers in the Photocatalytic CO2 Reduction Reaction
Round 1
Reviewer 1 Report
This perspective provides the state of the art of the reported dyad systems composed of Zn porphyrin and metal complex catalysts that has been used for improving the performance of photocatalytic systems. The perspective on this field is timely, given the high research activity on this topic. I think this perspective will be publishable after revision. The authors are encouraged to consider the following suggestions:
1. When talking about the reduction behavior of Zn porphyrin, it would be better to cite the relative OERS and CV cures in the perspective.
2. The following references are currently missing from the paper that would be good to include:
1) Porous fixed-bed photoreactor for boosting C–C coupling in photocatalytic CO2 reduction. eScience, 2(4), 428-437.
2) Construction of Z-Scheme In2S3-TiO2 for CO2 Reduction under Concentrated Natural Sunlight. Chinese Journal of Structural Chemistry, 2022, 41(1): 2201034-2201039.
Author Response
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Author Response File: 
Author Response.pdf
Reviewer 2 Report
The work presents an excellent overview in the field of zinc porphyrin-based photosensitizers. However, I would recommend adding more literature published in the last few years (2019-2023). Also, a table with various sensitizers, solvents used and catalytic properties would greatly simplify the perception of information.
1. in the introduction, it would be appropriate to compare the catalytic properties of metal complexes and some other photocatalysts for CO2 reduction, such as semiconductors.
2. description of the charge transfer in the Z-scheme is necessary (line 47)
3. more attention needs to be paid to the role of solvents in photocatalytic systems. For example, there is no discussion in lines 174-178 about increase in activity in BIH/TEOA system.
4. also, CO2 reduction products require discussion. Heterogeneous catalysts often lead to the formation of a mixture of products, CO, methane, and formaldehyde. It is necessary to emphasize the features of the process with the participation of sensitizers that lead to the formation of CO and absence CH4 or other compounds.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Manuscript ID: catalysts-2151393; entitled “Porphyrins Acting as Photosensitizers in the Photocatalytic CO2 Reduction Reaction”. In this article, the author focused on reported dyad systems composed of Zn porphyrin and metal complex catalysts and discussed the problems they faced and also introduced two types of the Zn porphyrin-Re complex systems that achieved high durability and efficiency in the photocatalytic CO2 reduction by solving these problems. Their presentation on paper writing was not so exciting. But the topic is interesting for the referee. Therefore, I recommend publication only after major revisions.
1) The abstract is not impressive in this paper. The author needs to change the abstract. Include the motivation and necessity of this Perspective.
2) In the introduction, the author didn’t provide more information regarding the Photocatalytic CO2 reduction reaction. The author needs to include more introduction for the photocatalytic part.
3) In Abstract Line 13: correct the CO2 presentation.
4) Why most porphyrins are used Zn compared to other metals, any specific reason, needs to explain clearly. I think that the author needs to include detailed studies and the advantages and drawbacks of these applications.
5) Page No:3, Line 72: The author has written “Magnesium porphyrins are highly sensitive toward acid’. I agree with the sentence. But Zn porphyrins are also highly sensitive toward acid. Comment on these issues and include the proper reasons for better understanding.
6) Page No.4; Line 138-139: the author has written “The fluorescence quenching resulted from the intramolecular electron transfer from the S1 of porphyrin to the Re complex.” The author needs to include where exited (porphyrin).
7) Page NO. 6, line 223: is it free-base or Zn porphyrin or free-base and Zn porphyrin? Needs to correct.
8) In page No7 and 8: I didn’t find the free base H2P-phen=Re absorption spectra and emission spectra. Include both spectrums and compared them with Zn porphyrin.
9) It is a perspective article. So, the author needs to decrease/shorter the conclusions
10) Please verify each sentence of this paper, Some typo errors.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Thank you to the author for addressing all the raised comments from reviewers. The authors have carried out the modifications and the corrections to the queries raised and indeed have provided more information in the revised version. Therefore, I recommend this manuscript for publication in Catalysts as it is without further modifications.
