Designed Synthesis of PDI/BiOCl-BiPO₄ Composited Material for Boosted Photocatalytic Contaminant Degradation

Round 1

Reviewer 1 Report

Please see the attachment.

Comments for author File: Comments.pdf

Author Response

Dear Editor,

 

We have made the major revision to this manuscript according to the comments of the reviewers and your suggestions. Point-by-point replies to the reviewer’s comments are attached to this letter. We greatly appreciate you and the helpful suggestions of the reviewers, and we believe that we have adequately addressed their concerns. Please feel free to let us know if you need further clarifications.

Thank you very much for considering the manuscript for publication as an article paper in Catalysts.

 

 

 

Best regards.

Sincerely yours,

Prof. Huaqiang Zhuang

College of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou 362000, P. R. China

Email: [email protected]

 

 

 

 

 

 

 

 

 

 

 

Point-by-point Response to the #Reviewer

Comments:

This work “Designed synthesis of PDI/BiOCl-BiPO4 composited material 2 for boosted photocatalytic contaminant degradation” reports PDI-BiOCl-BiVO4 ternary composites for their photocatalytic activity. The results are presented with proper experimental proofs. However, the mechanism and conclusion part needs to be discussed in detail. Some of the experiments are missing which are crucial for photocatalysts (see comments). I recommend this work to be published after major revision.
1. In the introduction, there were reports of composite materials exhibiting ~94.5 % TC degradation under 80-90 minutes, while in this report the activity is not upto these reports. Why you choose this system and what is the contribution of this work in advancement of science in the field compared to current literature?
2. The activity of catalysts is not calculated, calculate the degradation of TC and RhB and compare the results in discussion. Compare the results of this study with the literature in tabular form.
3. In photocatalytic study section, calculate the rate of reaction for different catalysts and compare these results with other literature in tabular form. Reusability and catalytic stability studies are missing, add these results. (see reference: DOI: 10.1039/D1CY01644J, Catal. Sci. Technol., 2022, 12, 6704)
4. In EIS Nyquist’s plots, no semi-circle is visible. How you reach to conclusion based on radius of semicircle?
5. In the introduction and experimental section, there is mention of SEM analysis, but I did not find any discussion or SEM images in the results and discussion part. Provide SEM and EDX results with discussion.
6. Mechanism is not properly discussed, as to confirm the it is type II heterojunction or Z-scheme system you need to calculate band positions (CBM and VBM) for the catalyst individually (see reference: doi.org/10.1021/acsomega.8b01054), and then compare it with redox potentials for hydroxyl radicals (•OH) and superoxide radicals (•O2-) formation by constructing a proper energy level diagram to show the proposed mechanism (see reference: DOI: 10.1039/D1MA00304F Mater. Adv., 2021, 2, 4832).
7. P-5, L-180: rewrite the line.
8. Thoroughly, check the manuscript for grammatical errors and typos.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Question 1. In the introduction, there were reports of composite materials exhibiting ~94.5 % TC degradation under 80-90 minutes, while in this report the activity is not upto these reports. Why you choose this system and what is the contribution of this work in advancement of science in the field compared to current literature?
Response 1: Thanks for the referee’s kind suggestion. Recently, our group has focused on the research of PDI and BiOCl materials in the field of photocatalytic contaminant degradation, so we try to couple with them to construct the efficient composite material. In addition, some previous reports did exhibit the good photocatalytic performance for TC degradation. Our work did not display the excellent photocatalytic active for TCH degradation, but the design concept of the ternary composite materials and novel PDI/BiOCl-BiPO₄ material show a certain degree of innovation and creation.

 

Question 2: The activity of catalysts is not calculated, calculate the degradation of TC and RhB and compare the results in discussion. Compare the results of this study with the literature in tabular form.

Response 2: Thanks for the referee’s comments. The degradation efficiency of TCH and RhB contaminants has been added in the manuscript. Sentence “Thereinto, the degradation efficiencies of PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 98%, 97% and 79% respectively, as shown in Fig.S1.” has been revised and added in the manuscript. Sentences “The degradation efficiency of tetracycline hydrochloride degradation for PDI, BiOCl-BiPO₄, PDI(2%)/BiOCl-BiPO₄, PDI(5%)/BiOCl-BiPO₄ and PDI(8%)/BiOCl-BiPO₄ samples was shown in Fig. S3. Obviously, the degradation efficiencies of PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 81%, 77% and 60% simulated solar light irradiation, respectively.”have been revised and added in the manuscript.

 

Figure S1. The degradation efficiency of all of as-prepared samples for RhB degradation.

Figure S2. The degradation efficiency of tetracycline hydrochloride degradation for PDI, BiOCl-BiPO₄, PDI(2%)/BiOCl-BiPO₄, PDI(5%)/BiOCl-BiPO₄ and PDI(8%)/BiOCl-BiPO₄ samples under simulated solar light irradiation.

 

 

Question 3: In photocatalytic study section, calculate the rate of reaction for different catalysts and compare these results with other literature in tabular form. Reusability and catalytic stability studies are missing, add these results. (see reference: DOI: 10.1039/D1CY01644J, Catal. Sci. Technol., 2022, 12, 6704)

Response 3: Thanks for the referee’s kind suggestion. The stability test of PDI(5%)/BiOCl-BiPO₄ sample has been added in the manuscript. Sentences “In order to further explore the stability of PDI/BiOCl-BiPO₄ composite photocatalysts, the PDI(5%)/BiOCl-BiPO₄ sample was continuously investigated, as shown in Fig. S3. There appears slight decrease for the RhB degradation efficiency of PDI(5%)/BiOCl-BiPO₄ sample after three cycles, suggesting that the PDI(5%)/BiOCl-BiPO₄ composite photocatalyst possesses the stability and reusability.” have been revised and added in the manuscript.

Figure S3. Stability test of PDI(5%)/BiOCl-BiPO₄ sample for RhB degradation.

 

The Plot of -ln (C_t/C₀) vs. irradiation time shows RhB and TCH degradation kinetics in Figs. S2 and S5. Sentences “The composite materials showed a close degradation efficiency in 150 min degradation time, but the degradation rate of PDI(5%)/BiOCl-BiPO₄ was much higher than that of the other samples, as displayed in Fig. S2. The apparent rate constants (k) of the RhB degradation for PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 0.037 min^-1, 0.027 min^-1 and 0.07 min^-1.” have been revised and added in the manuscript. Sentences “The degradation efficiency of tetracycline hydrochloride degradation for PDI, Bi-OCl-BiPO₄, PDI(2%)/BiOCl-BiPO₄, PDI(5%)/BiOCl-BiPO₄ and PDI(8%)/BiOCl-BiPO₄ samples was shown in Fig. S4. Obviously, the degradation efficiencies of PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 81%, 77% and 60% simulated solar light irradiation, respectively. The plot of -ln (C_t/C₀) vs. irradiation time for TCH degradation kinetics furtherly demonstrated the enhancement photocatalytic performance of PDI(5%)/BiOCl-BiPO₄. The apparent rate constants (k) of the RhB degradation for PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 0.037 min^-1, 0.027 min^-1 and 0.07 mim^-1, as displayed in Fig. S5.This result is consistent with the result of RhB degradation, indicating the advantage of PDI incorporated.” have been revised and added in the manuscript.

Figure S2. Plot of -ln (Ct/C0) vs. irradiation time shows RhB degradation kinetics.

 

Figure S5. Plot of -ln (C_t/C₀) vs. irradiation time shows TCH degradation kinetics under simulated solar light irradiation.

 

Sentence “Besides, the comparison of degradation efficiencies of different photocatalysts was exhibited in Table 1, which fully demonstrated the advantages of PDI/BiOCl-BiPO₄ composite photocatalysts.” has been revised and added in the manuscript.

 

Table 1. Comparison of degradation efficiencies of different photocatalysts

Catalyst	Pollutant	Pollutant concentration	Amount of catalyst	Photocatalytic efficiency	References
BiOCl	4-CP	50 mg L-1,50 mL	50 mg	69%, 300 min	33
Bi24O31Cl10	TCH	10 mg L-1, 100 mL	100 mg	80.1%, 150 min	34
Cu2O–TiO2	TCH	30 mg L-1, 50 mL	50 mg	81.4%, 240 min	35
CdS-TiO2	TCH	50 mg L-1, 50 mL	50 mg	87%, 480 min	36
Bi2.5Sr1.5Nb2Ti0.5Cr0.5O12	TC	6.66 mg L-1, 50 mL	100 mg	89%, 300 min	37
PDI(5%)/BiOCl-BiPO4	RhB	10 mg L-1, 50 mL	25 mg	98%, 150 min	Present work
PDI(5%)/BiOCl-BiPO4	TCH	10 mg L-1, 50 mL	25 mg	81%, 150 min	Present work

 

 

Question 4: In EIS Nyquist’s plots, no semi-circle is visible. How you reach to conclusion based on radius of semicircle?
 

Response 4: Thanks for the referee’s kind suggestion. Although the semi-circle didn’t were completely displayed in EIS Nyquist’s plots, the different diameters of arc radius could be figured out from their results. The previous works (Journal of Alloys and Compounds, 902 (2022) 163752.; Separation and Purification Technology, 248 (2020) 117040.; Ceramics International, 46 (2020) 460-467.) have clearly demonstrated the conclusion.

 

Question 5: In the introduction and experimental section, there is mention of SEM analysis, but I did not find any discussion or SEM images in the results and discussion part. Provide SEM and EDX results with discussion.

Response 5: Thanks for the referee’s comments. The SEM analysis has been added in the manuscript. Sentences “Furthermore, the SEM images of BiOCl-BiPO₄, PDI and PDI(5%)/BiOCl-BiPO₄ were shown in Fig. 3. Distinctly, Figs. 3 a and b showed that the BiOCl-BiPO₄ sample was composed of some particles and blocks. Figs. 3 c and d displayed that the PDI material was a layered structure to form the large-block material. After the combination of PDI and BiOCl-BiPO₄ material, their morphologies were reconstructed, as exhibited in Figs. 3 e and f.”have been revised and added in the manuscript.

 

 

Figure 3 Figure 3 SEM images of BiOCl-BiPO4 (a and b), PDI (c and d) and PDI(5%)/BiOCl-BiPO4 (e and f).

 

Question 6: Mechanism is not properly discussed, as to confirm the it is type II heterojunction or Z-scheme system you need to calculate band positions (CBM and VBM) for the catalyst individually (see reference: doi.org/10.1021/acsomega.8b01054), and then compare it with redox potentials for hydroxyl radicals (•OH) and superoxide radicals (•O2-) formation by constructing a proper energy level diagram to show the proposed mechanism (see reference: DOI: 10.1039/D1MA00304F Mater. Adv., 2021, 2, 4832).

Response 6: Thanks for the referee’s kind suggestion. The mechanism has been reconsidered. Sentences “Because of the existence of p-n heterostructure between BiOCl and BiPO₄ materials [39, 40], the photo-generated electrons will migrate toward BiPO₄. Besides, it can be obtained from the previous reports that the E_CB and E_VB for BiOCl (BiPO₄) were − 0.43 and 3.02 eV (− 0.34 and 3.53 eV for BiPO₄) respectively [41], and the E_CB and E_VB of PDI were -0.93 and 0.87 eV [42]. If the separation and transfer pathway of photo-generated electron-hole pairs follows the type Ⅱ heterojunction, the electrons in the CB position of PDI will be transferred to the CB position of BiOCl-BiPO₄ and holes in the VB position of BiOCl-BiPO₄ will be transferred to VB position of PDI. However, when the holes of VB position of BiOCl-BiPO₄ were transferred to the VB position of PDI, it did not have enough ability to oxidize H₂O into the •OH radicals (E_•OH/H2O = +2.68 V vs. NHE), [43] because it owned more negative potential.” have been revised and added in the manuscript.

 

Question 7: P-5, L-180: rewrite the line.

Response 7: Thanks for the referee’s kind suggestion. The sentence has been rewritten. Sentence “It can be obtained that the PDI/BiOCl-BiPO₄ composited material showed an enhancement photocatalytic performance in comparison to BiOCl-BiPO₄ and PDI materials.” has been revised and added in the manuscript.

 

 

Question 8: Thoroughly, check the manuscript for grammatical errors and typos.

Response 8: Thanks for the referee’s kind suggestion. These mistakes have been revised in the manuscript. In addition, the English of the manuscript has been checked and improved. Thanks again for your clever and useful suggestion.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

In this manuscript, entitled “Designed synthesis of PDI/BiOC-BiPO₄ composited material for boosted photocatalytic contaminant degradation”, Kai Yang and co-authors reported the degradation of tetracycline hydrochloride and rhodamine B by the prepared ternary PDI(5%)/ BiOC-BiPO4 composited materials. The conduced active species trapping experiment and proposed reaction mechanism indicating that this newly prepared photocatalysts with efficient degradation performance because the introduction of PDI can reduce the recombination of photo-generated holes and electrons and be beneficial to the photocatalytic reaction process. The useful insights into the design and synthesis of this work guarantees its high importance for specialists and significant general interest. And I believe it will attract considerable attention in photocatalyst materials and it should be published in Catalysts after some revisions:

1. The authors claimed that the optimized PDI(5%)/BiOC-BiPO₄ composited materials with excellent photocatalytic activity for tetracycline hydrochloride and rhodamine B. The quantitative data of degradation efficiency should be provided and comparison of the other reported photocatalysts with PDI(5%)/BiOC-BiPO₄ would emphasize the claimed advantage of this study.

2. For the photocatalytic activity of tetracycline hydrochloride and rhodamine B degradation in Figure 4 and Figure 5, have the authors done repetitive studies? If so, then they should show the error bars in the relative figures.

3. From the referee point of view, the reaction mechanism suggested (Figure 9) and discussed in the corresponding text cannot fully support the photocatalytic degradation process. The solid experiment evidence should be provided, or the literature research to support the authors’ idea. The active species trapping experiments in Figure 6 only compared the degradation efficiency between different photocatalysts, but it cannot confirm that the generation of active species (h⁺ and •O^2-) directly. There are many methods to prove the generation of catalytic active species, for example, electron paramagnetic resonance spectroscopy, nuclear magnetic resonance spectroscopy, etc.

4. How about the reusability of the photocatalyst? Can the photocatalyst be regenerated?

5. In experimental part the supplies of materials and their degree of purity must be added.

6. The format of the References should be double checked.

e.g., 4). Olusegun, S. J.; Larrea, G.; Osial, M.; Jackowska, K.; Krysinski, P., Photocatalytic Degradation of Antibiotics by 378 Superparamagnetic Iron Oxide Nanoparticles. Tetracycline Case. In Catalysts, 2021; Vol. 11; 5). He, Z.; Siddique, M. S.; Yang, H.; Xia, Y.; Su, J.; Tang, B.; Wang, L.; Kang, L.; Huang, Z., Novel Z-scheme In2S3/Bi2WO6 380 core-shell heterojunctions with synergistic enhanced photocatalytic degradation of tetracycline hydrochloride. Journal of 381 Cleaner Production 2022,339, 130634; et al.

Comments for author File: Comments.pdf

Author Response

Dear Editor,

 

We have made the major revision to this manuscript according to the comments of the reviewers and your suggestions. Point-by-point replies to the reviewer’s comments are attached to this letter. We greatly appreciate you and the helpful suggestions of the reviewers, and we believe that we have adequately addressed their concerns. Please feel free to let us know if you need further clarifications.

Thank you very much for considering the manuscript for publication as an article paper in Catalysts.

 

 

 

Best regards.

Sincerely yours,

Prof. Huaqiang Zhuang

College of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou 362000, P. R. China

Email: [email protected]

 

 

 

 

 

 

 

 

 

 

 

Point-by-point Response to the #Reviewer

Comments:

In this manuscript, entitled “Designed synthesis of PDI/BiOC-BiPO4 composited material for boosted photocatalytic contaminant degradation”, Kai Yang and co-authors reported the degradation of tetracycline hydrochloride and rhodamine B by the prepared ternary PDI(5%)/BiOC-BiPO4 composited materials. The conduced active species trapping experiment and proposed reaction mechanism indicating that this newly prepared photocatalysts with efficient degradation performance because the introduction of PDI can reduce the recombination of photogenerated holes and electrons and be beneficial to the photocatalytic reaction process. The useful insights into the design and synthesis of this work guarantees its high importance for specialists and significant general interest. And I believe it will attract considerable attention in photocatalyst materials and it should be published in Catalysts after some revisions:
1. The authors claimed that the optimized PDI(5%)/BiOC-BiPO4 composited materials with excellent photocatalytic activity for tetracycline hydrochloride and rhodamine B. The quantitative data of degradation efficiency should be provided and comparison of the other reported photocatalysts with PDI(5%)/BiOC-BiPO4 would emphasize the claimed advantage of this study.
2. For the photocatalytic activity of tetracycline hydrochloride and rhodamine B degradation in Figure 4 and Figure 5, have the authors done repetitive studies? If so, then they should show the error bars in the relative figures.
3. From the referee point of view, the reaction mechanism suggested (Figure 9) and discussed in the corresponding text cannot fully support the photocatalytic degradation process. The solid experiment evidence should be provided, or the literature research to support the authors’ idea. The active species trapping experiments in Figure 6 only compared the degradation efficiency between different photocatalysts, but it cannot confirm that the generation of active species (h+ and •O2-) directly. There are many methods to prove the generation of catalytic active species, for example, electron paramagnetic resonance spectroscopy, nuclear magnetic resonance spectroscopy, etc.
4. How about the reusability of the photocatalyst? Can the photocatalyst be regenerated?
5. In experimental part the supplies of materials and their degree of purity must be added.

6. The format of the References should be double checked.

e.g., 4). Olusegun, S. J.; Larrea, G.; Osial, M.; Jackowska, K.; Krysinski, P., Photocatalytic Degradation of Antibiotics by 378 Superparamagnetic Iron Oxide Nanoparticles. Tetracycline Case. In Catalysts, 2021; Vol. 11; 5). He, Z.; Siddique, M. S.; Yang, H.; Xia, Y.; Su, J.; Tang, B.; Wang, L.; Kang, L.; Huang, Z., Novel Z-scheme In2S3/Bi2WO6 380 core-shell heterojunctions with synergistic enhanced photocatalytic degradation of tetracycline hydrochloride. Journal of 381 Cleaner Production 2022,339, 130634; et al

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Question 1. The authors claimed that the optimized PDI(5%)/BiOC-BiPO4 composited materials with excellent photocatalytic activity for tetracycline hydrochloride and rhodamine B. The quantitative data of degradation efficiency should be provided and comparison of the other reported photocatalysts with PDI(5%)/BiOC-BiPO4 would emphasize the claimed advantage of this study.
Response 1: Thanks for the referee’s comments. The degradation efficiency of TCH and RhB contaminants has been added in the manuscript. Sentence “Thereinto, the degradation efficiencies of PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 98%, 97% and 79% respectively, as shown in Fig.S1.” has been revised and added in the manuscript. Sentences “The degradation efficiency of tetracycline hydrochloride degradation for PDI, BiOCl-BiPO₄, PDI(2%)/BiOCl-BiPO₄, PDI(5%)/BiOCl-BiPO₄ and PDI(8%)/BiOCl-BiPO₄ samples was shown in Fig. S3. Obviously, the degradation efficiencies of PDI(5%)/BiOCl-BiPO₄, BiOCl-BiPO₄ and PDI samples were 81%, 77% and 60% simulated solar light irradiation, respectively.”have been revised and added in the manuscript.

Figure S1. The degradation efficiency of all of as-prepared samples for RhB degradation.

Figure S2. The degradation efficiency of tetracycline hydrochloride degradation for PDI, BiOCl-BiPO₄, PDI(2%)/BiOCl-BiPO₄, PDI(5%)/BiOCl-BiPO₄ and PDI(8%)/BiOCl-BiPO₄ samples under simulated solar light irradiation.

 

Table 1. Comparison of degradation efficiencies of different photocatalysts

Catalyst	Pollutant	Pollutant concentration	Amount of catalyst	Photocatalytic efficiency	References
BiOCl	4-CP	50 mg L-1,50 mL	50 mg	69%, 300 min	33
Bi24O31Cl10	TCH	10 mg L-1, 100 mL	100 mg	80.1%, 150 min	34
Cu2O–TiO2	TCH	30 mg L-1, 50 mL	50 mg	81.4%, 240 min	35
CdS-TiO2	TCH	50 mg L-1, 50 mL	50 mg	87%, 480 min	36
Bi2.5Sr1.5Nb2Ti0.5Cr0.5O12	TC	6.66 mg L-1, 50 mL	100 mg	89%, 300 min	37
PDI(5%)/BiOCl-BiPO4	RhB	10 mg L-1, 50 mL	25 mg	98%, 150 min	Present work
PDI(5%)/BiOCl-BiPO4	TCH	10 mg L-1, 50 mL	25 mg	81%, 150 min	Present work

 

Sentence “Besides, the comparison of degradation efficiencies of different photocatalysts was exhibited in Table 1, which fully demonstrated the advantages of PDI/BiOCl-BiPO₄ composite photocatalysts.” has been revised and added in the manuscript.

 

Question 2: For the photocatalytic activity of tetracycline hydrochloride and rhodamine B degradation in Figure 4 and Figure 5, have the authors done repetitive studies? If so, then they should show the error bars in the relative figures.

Response 2: Thanks for the referee’s comments. The photocatalytic performance of PDI/BiOCl-BiPO₄ composite photocatalysts has been carried out to degrade the tetracycline hydrochloride and rhodamine B under different experimental conditions to verify the advantage of composite materials and its stability.  

.

 

Question 3: From the referee point of view, the reaction mechanism suggested (Figure 9) and discussed in the corresponding text cannot fully support the photocatalytic degradation process. The solid experiment evidence should be provided, or the literature research to support the authors’ idea. The active species trapping experiments in Figure 6 only compared the degradation efficiency between different photocatalysts, but it cannot confirm that the generation of active species (h+ and •O2-) directly. There are many methods to prove the generation of catalytic active species, for example, electron paramagnetic resonance spectroscopy, nuclear magnetic resonance spectroscopy, etc.
Response 3: Thanks for the referee’s kind suggestion. The possible reaction mechanism has been revised and added in the manuscript. Thanks for the referee’s kind suggestion. The mechanism has been reconsidered. Sentences “Because of the existence of p-n heterostructure between BiOCl and BiPO₄ materials [39, 40], the photo-generated electrons will migrate toward BiPO₄. Besides, it can be obtained from the previous reports that the E_CB and E_VB for BiOCl (BiPO₄) were − 0.43 and 3.02 eV (− 0.34 and 3.53 eV for BiPO₄) respectively [41], and the E_CB and E_VB of PDI were -0.93 and 0.87 eV [42]. If the separation and transfer pathway of photo-generated electron-hole pairs follows the type Ⅱ heterojunction, the electrons in the CB position of PDI will be transferred to the CB position of BiOCl-BiPO₄ and holes in the VB position of BiOCl-BiPO₄ will be transferred to VB position of PDI. However, when the holes of VB position of BiOCl-BiPO₄ were transferred to the VB position of PDI, it did not have enough ability to oxidize H₂O into the •OH radicals (E_•OH/H2O = +2.68 V vs. NHE), [43] because it owned more negative potential.” have been revised and added in the manuscript.

  In addition, the active species trapping experiments have been able to prove the generation of active species. The t-BuOH, EDTA-2Na and p-benzoquinone (BQ) were used as the scavengers to trap hydroxyl radicals (•OH), holes (h⁺) and superoxide radicals (•O₂^-), respectively. Some previous reports, Such as Chemical Engineering Journal, 429 (2022) 132105, Applied Surface Science, 544 (2021) 148885, Journal of Environmental Sciences, 101 (2021) 351-360, and Chemical Engineering Journal, 382 (2020) 122842, have clearly demonstrated the effective means.

 

Question 4: How about the reusability of the photocatalyst? Can the photocatalyst be regenerated?
Response 4: Thanks for the referee’s kind suggestion. The stability test of PDI(5%)/BiOCl-BiPO₄ sample has been added in the manuscript. Sentences “In order to further explore the stability of PDI/BiOCl-BiPO₄ composite photocatalysts, the PDI(5%)/BiOCl-BiPO₄ sample was continuously investigated, as shown in Fig. S3. There appears slight decrease for the RhB degradation efficiency of PDI(5%)/BiOCl-BiPO₄ sample after three cycles, suggesting that the PDI(5%)/BiOCl-BiPO₄ composite photocatalyst possesses the stability and reusability.” have been revised and added in the manuscript.

Figure S3. Stability test of PDI(5%)/BiOCl-BiPO₄ sample for RhB degradation.

 

Question 5: In experimental part the supplies of materials and their degree of purity must be added.

Response 5: Thanks for the referee’s comments. The relevant materials have been added in the experimental section. Sentences “All the chemicals involving in synthetic catalysts were of analytical reagent grade and no further purification. Bismuth nitrate pentahydrate (Bi(NO₃)₃·5H₂O), sodium phosphate dibasic dodecahydrate (NaH₂PO₄∙12H₂O), hexamethylene tetramine (C₆H₁₂N₄), potassium chloride (KCl), lithiumchloride (LiCl), perylene-3,4,9,10-tetracarboxylic dianhydride (PTCD), imidazole (C₃H₄N₂), 3-aminopro-pionic acid (C₃H₇NO₂) trimethylamine (C₆H₁₅N), hydrochloric acid (HCl), nitric acid (HNO₃), ethanol (EtOH), rhodamine B (RhB), tetracycline hydrochloride (TCH) benzoquinone (BQ), tert-butyl alcohol (t-BuOH), ethylenediaminetetraacetic acid disodium (EDTA-2Na). Deionized water was used for all the experiments.” have been revised and added in the manuscript.

 

Question 6: The format of the References should be double checked.

e.g., 4). Olusegun, S. J.; Larrea, G.; Osial, M.; Jackowska, K.; Krysinski, P., Photocatalytic Degradation of Antibiotics by 378 Superparamagnetic Iron Oxide Nanoparticles. Tetracycline Case. In Catalysts, 2021; Vol. 11; 5). He, Z.; Siddique, M. S.; Yang, H.; Xia, Y.; Su, J.; Tang, B.; Wang, L.; Kang, L.; Huang, Z., Novel Z-scheme In2S3/Bi2WO6 380 core-shell heterojunctions with synergistic enhanced photocatalytic degradation of tetracycline hydrochloride. Journal of 381 Cleaner Production 2022,339, 130634; et al.

Response 6: Thanks for the referee’s comments. The relevant references have been revised.

References

 

1. Wu, C.-J.; Valerie Maggay, I.; Chiang, C.-H.; Chen, W.; Chang, Y.; Hu, C.; Venault, A., Removal of tetracycline by a photocatalytic membrane reactor with MIL-53(Fe)/PVDF mixed-matrix membrane. Chem. Eng. J. 2023, 451, 138990.
2. Guo, F.; Huang, X.; Chen, Z.; Sun, H.; Shi, W., Investigation of visible-light-driven photocatalytic tetracycline degradation via carbon dots modified porous ZnSnO₃ cubes: Mechanism and degradation pathway. Sep. Purif. Technol. 2020, 253, 117518.
3. Jiang, H.; Wang, Q.; Chen, P.; Zheng, H.; Shi, J.; Shu, H.; Liu, Y., Photocatalytic degradation of tetracycline by using a regenerable (Bi)BiOBr/rGO composite. J. Clean. Prod. 2022, 339, 130771.
4. Olusegun, S. J.; Larrea, G.; Osial, M.; Jackowska, K.; Krysinski, P., Photocatalytic Degradation of Antibiotics by Superparamagnetic Iron Oxide Nanoparticles. Tetracycline Case. Catalysts, 2021, 11.
5. He, Z.; Siddique, M. S.; Yang, H.; Xia, Y.; Su, J.; Tang, B.; Wang, L.; Kang, L.; Huang, Z., Novel Z-scheme In₂S₃/Bi₂WO₆ core-shell heterojunctions with synergistic enhanced photocatalytic degradation of tetracycline hydrochloride. J. Clean. Prod. 2022, 339, 130634.
6. Cheng, M.; Zhang, Y.; Lai, B.; Wang, L.; Yang, S.; Li, K.; Wang, D.; Wu, Y.; Chen, G.-H.; Qian, J., Nitrogen and phosphorus co-doped porous carbons (NPCs) for peroxydisulfate (PDS) activation towards tetracycline degradation: Defects enhanced adsorption and non-radical mechanism dominated by electron transfer. Chem. Eng. J. 2022, 140615.
7. Chen, W.; Huang, J.; He, Z.-C.; Ji, X.; Zhang, Y.-F.; Sun, H.-L.; Wang, K.; Su, Z.-W., Accelerated photocatalytic degradation of tetracycline hydrochloride over CuAl₂O₄/g-C₃N₄ p-n heterojunctions under visible light irradiation. Sep. Purif. Technol. 2021, 277, 119461.
8. Pei, C.-Y.; Chen, Y.-G.; Wang, L.; Chen, W.; Huang, G.-B., Step-scheme WO₃/CdIn₂S₄ hybrid system with high visible light activity for tetracycline hydrochloride photodegradation. Appl. Surf. Sci. 2021, 535, 147682.
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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

For the revised manuscript "Designed synthesis of PDI/BiOCl-BiPO4 composited material for boosted photocatalytic contaminant degradation" the authors have addressed most of the issues. However, some comments still need answers along with some new comments that arise.

The issues are listed below:

1.       To calculate rate of a reaction by pseudo-first order reaction, the linear plot should pass through at least 2 points, but in Fig.S2, except for PDI and blank none of the linear plots pass through two points. Similarly, in Fig.S5, the plot should pass through the origin (0,0), but here, except for PDI and blank, none of the plots pass through the origin. The reaction rate calculated from these plots is wrong. Recalculate the rates for these reactions and report them in the manuscript.

2.       Fig.10 is not changed, although it was clearly mentioned in previous comments to calculate the CBM, VBM and redox potentials for the catalysts and mention them in the figure 10.

3.       What about EDX? Why is it missing? It can tell about the ratio of elements and confirm the catalyst composition, whether the B

4.       For stability, XRD pattern of catalysts after reaction (cyclic tests) must be recorded to confirm whether the decrease in activity is due to structural degradation or might be due to loss of some co-catalyst.

5.       For, EIS Nyquist plots, these works (Journal of Alloys and Compounds, 902 (2022) 163752.; Separation and Purification Technology, 248 (2020) 117040.; Ceramics International, 46 (2020) 460-467.) do not clearly present the results, as in these works, no arc / semicircle is observable and still they mentioning about arc or its diameter. As mentioned in the text, “the diameter of arc

radius on the EIS Nyquist plot….P-9,L-278) does not make sense. First of all, there is no arc/ semicircle visible and secondly, what does “diameter of arc radius” mean? Repeat the result as to compare the data, some semicircle-like feature must be visible in EIS plots.

 

6.       Check the references again, as Ref. 33 is wrongly cited.

Author Response

Dear Reviewer,

We have made the major revision to this manuscript according to the comments of the reviewers and your suggestions. Point-by-point replies to the reviewer’s comments are attached (see the attachment). We greatly appreciate the helpful suggestions of the reviewers, and we believe that we have adequately addressed their concerns. Please feel free to let us know if you need further clarifications.

Thank you very much for considering the manuscript for publication as an article paper in Catalysts.

Best regards.

Sincerely yours,

Prof. Huaqiang Zhuang

College of Chemical Engineering and Materials Science, Quanzhou Normal University, Quanzhou 362000, P. R. China

Email: [email protected]

Author Response File: Author Response.pdf