Bio-Coated Graphitic Carbon Nitrides for Enhanced Nitrobenzene Degradation: Roles of Extracellular Electron Transfer
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors1.The target of this paper is not clear. What is the target of nitrobenzene degradation or ammonia production? May be like water purification or energy production, I don’t Know, it is not clear.
2.Why do you choose fluorinated and ND g-C3N4 as modification? this point must be clarified.
3.Why don’t you try to do the effect of weight (for adding different volume of bio-hybrid material)?
4.-There are unclarity in the most of figures, graphs and tables like each material must be signed and cycled in SEM images- Peaks in XRD patterns must be labeled with name and the number of each phase – The same previous comment for XPS and FTIR – The numbers in Table 1 are conflicted ……..etc).
-Try to get a single format for all figures and graphs like the same color and style.
5.Fig.1 a (SEM image), you say that E coli cells break, the problem is that g-C3N4 is not appeared in the image.
6.-Fig.2 a (XRD pattern), you say that E coli cells break in presence of g-C3N4, you have to explain why there are no changes in peaks of E coli and it looks like other samples.
-You should test the different graphitic materials without biological material to identify its peaks.
-You don’t talk about 45o, 56o and 75o peaks
7.-Fig.2c (FTIR pattern), The same problem, there are peaks (from 1600 to 400) that you don’t talk about them.
-The red spectrum has differences from others spectrum at 3280cm-1, why is that?
8.Fig.4 (DRS) The resolution and format are so bad and not clear. And we do not know which is which.
9.- For photocatalytic performance, you should do Zeta potential or point of zero charge to get more information about the surface and choose the best condition (pH).
- You should increase the reaction time as the rate is not affected significantly by the time, you might get better result.
10.- Role of dissolved oxygen: After dissolving oxygen, f g-C3N4 becomes better than ND g-C3N4, Why?
-What is the benefit of UV pretreatment and you did not discuss the bad result for applying it.
11.You have to do scavenger tests to investigate which active radical responsible for degradation.
Comments on the Quality of English LanguageKeep modifying it.
Author Response
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Reviewer 2 Report
Comments and Suggestions for AuthorsThe authors describe a research article entitled “Bio-coated graphitic carbon nitrides for enhanced nitrobenzene degradation: Roles of extracellular electron transfer”. The topic of the manuscript is interesting, and the manuscript constitutes an interesting article concerning the development of photocatalysts for the degradation of pollutant. A detailed conclusion highlighting the main results of this work. The work is well-written and a well-constructed introduction has been established by the authors. Interesting and convincing results are also presented in this manuscript. Overall, I think that this is a manuscript that I recommend for publication after inclusion of minor revisions.
1. The authors mentioned in the abstract the visible light photocatalytic performance. What is the wavelength range of the xenon lamp used?
2. It is recommended to annotate the crystal planes and symbols in the XRD patterns to clearly reflect their corresponding phases.
3. Fig.9，suggest providing specific band potentials.
Author Response
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Reviewer 3 Report
Comments and Suggestions for Authors
1. English in the Manuscript should be thoroughly checked and corrected. Please check the spelling of the words in line 44 of the paper.
2. Abstract should be elaborated concisely.
3. Discuss about nitrobenzene in introduction.
4. Is this synthesis method a prototype? In other case authors should add relevant references.
5.The peaks of C1s and N1s high-resolution spectra should be analyzed with the corresponding references cited.
6. The units in Figure 4 and Figure 5 should be labeled within the figures.
7. The graphic information in Figure 6 should be supplemented and complete.
8. Table S1 and Table S2 are repeated. Adsorption ratios of nitrobenzene on pristine and bio-coated g-C3N4, ND-g-C3N4, and F-g-C3N4 need to be provided.
9. The authors should provide hydroxyl trapping experiments to verify ROS measurements.
10. The titles of Part IV and part V are repeated, please check and revise them carefully.
11.The Conclusions section should include:
* A highlight of your hypothesis, new concepts and innovations.
* A summary of key improvements compared to findings in literature
* Your vision for future work
Comments on the Quality of English LanguageModerate editing of English language required.
Author Response
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Reviewer 4 Report
Comments and Suggestions for AuthorsIn the article, Bio-coated graphitic carbon nitrides for enhanced nitrobenzene degradation: Roles of extracellular electron transfer. Pure g-C3N4, g-C3N4 with nitrogen defects (ND-g-C3N4), and fluorinated g-C3N4 (F-g-C3N4) were fabricated and then coated with representative bacteria, i.e., Escherichia coli MG 1655. The as-obtained bio-hybrids were characterized using integrated spectroscopic techniques, and the photocatalytic activities were then evaluated through the degradation of nitrobenzene in aqueous solution under visible light illumination. The adsorption of g-C3N4 nanoparticles was witnessed onto bio-aggregates, and surface hydrophilicity was convinced to be determined in the toxicity of photocatalysts in a dark environment. This work contains some new findings, however, in my opinion, some work needs to be further supplemented.
1. The Author should mention the lattice plane in each XRD peak with compare the standard JCPDS card No. Because the reported g-C3N4 is generally shown in the broad peak at 27o. So please check with proper references.
2. How to confirm the nitrogen defect in the ND-g-C3N4 samples. From Fig. 3 all of the N 1s spectra are the same. Are there any specific changes in the Fig. 3? Please discuss this in detail.
3. The authors must provide quantitative data to prove the defect's nature. Could you explain the weight % by either EDS and/or XPS spectra?
4. If possible, reusability tests should be performed.
5. More morphological characterization after catalytic or stability tests, such as the SEM image of the ND-g-C3N4 is needed.
6. Generally, the collection of literature looks poor. So, I suggest the author, should improve with more recent references related to g-C3N4 catalyst.
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Reviewer 5 Report
Comments and Suggestions for AuthorsThe manuscript describes a comprehensive study of biocoated g-C3N4 and a detailed analysis of morphological characteristics and composition. The efficiency of photocatalytic degradation of nitrobenzene is shown, the mechanisms of interaction of the photocatalyst with nitrobenzene are analyzed, and the role of E.Coli is shown.
The introduction includes references published earlier than 2018, newer articles should be added. Authors also should compare the efficiency of the developed photocatalysts with the results of other authors on the photocatalytic degradation of nitrobenzene.
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Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors addressed my questions and I would recommend the acceptance of this submission.
Comments on the Quality of English LanguageReseable Ok for publication.
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Reviewer 3 Report
Comments and Suggestions for AuthorsThe article has been modified according to the requirements and can be accepted.
Comments on the Quality of English LanguageMinor editing of English language required.
Author Response
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