A Study on the Evaluation Methods of Nitrogen Oxide Removal Performance of Photocatalytic Concrete for Outdoor Applications
Round 1
Reviewer 1 Report
This work devised and set up a simple experimental apparatus for evaluating the photocatalytic performance of materials in actual outdoor situations. It is valuable for environmental remediation. Therefore, we recommend this work for publication after minor revision.
1. Figure 2 showed that the intensity of the sunlight irradiation decreased from 1.06 p.m. to 4.06 p.m.. However, in line 121-123, it was stated that “the substantial light intensity was there regardless of the sun's location”. It is puzzling.
2. What kind of materials is the cover of the dark reactor?
3. In Figure 11, the quartz window should be transparent just like that in Figure 12.
4. There are some grammatical mistakes. For example, the phrase “On the other hand” in line 16, 25, and 58 should be used by coupling with “On the one hand”.
5. The subscript of TiO2 in the references should be checked carefully.
Author Response
The author expresses their gratitude to the reviewer for the valuable comments. All the comments are addressed, and the manuscript is amended accordingly. The detailed response is documented in the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The manuscript " A study on the evaluation methods of nitrogen oxide removal performance of photocatalytic concrete for outdoor applications " had been reviewed. The proposed publication is very interesting from an application point of view, but I have some comments:
1. More information regarding the photocatalyst should be added (chemical structure, crystal structure, absorbance range, how the photocatalyst was applied on the surfaces etc.).
2. The photocatalytic layer in the Fig.1 should be marked, because it is not clear.
3. The English writing should be improved in whole manuscript.
4. The abstract is too general.
5. Why exactly such measurement conditions were tested “NOx gas was supplied at a concentration of 3.0 ppm, a 112 flowrate of 3.0 L/min, and a relative humidity of 50%.”
6. The results are presented as a report rather than a publication.
7. All graphs should be corrected and presented in a better form.
8. How the NO concentration was analyzed? What kind of detector was used?
9. The NO photodegradation mechanism should be presented.
10. What are the decomposition intermediates?
Author Response
The author expresses their gratitude to the reviewer for the valuable comments. All the comments are addressed, and the manuscript is amended accordingly. The detailed response is documented in the attached file.
Author Response File: Author Response.pdf
