Evidence of Synergy Effects between Zinc and Copper Oxides with Acidic Sites on Natural Zeolite during Photocatalytic Oxidation of Ethylene Using Operando DRIFTS Studies

Round 1

Reviewer 1 Report

The authors describe in their manuscript entitled “Evidence of synergy effects between zinc and copper oxides with acidic sites on natural zeolite during photocatalytic oxidation of ethylene using operando DRIFTS studies” the synthesis, characterization, and photocatalytic oxidation testing of zinc and copper oxides on zeolite material. The developed structures were characterized using several methods and photocatalytic oxidation of ethylene performance was also discussed. The manuscript needs major revisions listed below before publication.

1.        In Table 2, the band gap value of FS_Zn/Cu is the highest (3.90) among FS_Zn, FS_Cu and FS_TiO2, while that of ZH_Zn/Cu is the lowest (2.65) among FS_Zn, FS_Cu and Z_Nat. Could you please give more explanation?

2.        In Figure 6, why ZH_Cu showed the highest ethylene adsorption but the lowest photocatalytic degradation among FS_Zn, FS_Zn/Cu and FS_TiO2?

3.        How about the additive amount of single metal oxide and the ratio of double metal oxide? 

4.        Please add the results of reaction kinetics.

5.        I consider the mechanism of photocatalytic degradation should be further disclosed.

6.        There are some literatures on Cu/Zn complexes over ZSM-5 or SiO2 applied in photocatalytic oxidation (10.1016/j.jhazmat.2021.125802), your innovation should be emphasized.

Author Response

Dear reviewer; we appreciate the comments done during the peer reviewing process. In the document below we try to answer your questions and we indicate in bold where they have been incorporated in the new manuscript. 

Please, see the attachment

Best regards

Norberto Abreu et al.

Author Response File: Author Response.pdf

Reviewer 2 Report

Abstract

1.      Abstract too general and superficial. Re-write the abstract by incorporating the results obtained from the experiments (statistical data). At least the best results obtained. So that the reader find the maximum information by reading the abstract, among the different combinations used which is best.

Introduction

1.      Please include the loss in statistics because of ethylene.

2.      Line 34: “Even at low concentration and temperature, ethylene can accelerate aging”, please mention the concentration of ethylene; at what concentration it can cause damage?

3.      Give more examples similar to titanium dioxide.

4.      Kindly highlight why only ZnO and CuO? There are other metal oxides with similar features, such as MnO, MgO, CoO, etc.

5.      Provide few examples, where ZnO and CuO have been used for similar purposes.

Materials and Methods

            Methodology was well presented.

1.      Please cite the reference articles, if the “modifications of the support” was done based on the previously published articles.

Results and Discussion

1.      Based on Band Gap Energy (ZH_Zn/Cu – 2.65, ZH_Zn – 2.75, ZH_Cu – 2.70, FS_TiO2 – 3.50), however from Figure 5 and 6, FS_TiO2 showed second best results even though the BGE is much higher than other modified zeolites. Please explain.

2.      Data obtained from the experiments was properly supported by the characterization results.

Conclusion

1.      If possible, please mention on how it can be further improved to achieve better results.

References

1.      Try to identify the literature to compare the results obtained from the present work with that of other published methods.

2.      Among the cited references in the “Results and Discussion” section, none of them were used for comparison of the removal efficiency.

Author Response

Dear reviewer; we appreciate the comments done during the peer reviewing process. In the document below we try to answer your questions and we indicate in bold where they have been incorporated in the new manuscript.

Please see the attachment

Best regards

Norberto Abreu et al.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have revised their manuscript accordingly. Now this manuscript can be published as it is.