A Green Chemistry and Energy- and Cost-Effective Approach in Innovative Advanced Oxidation Processes Through Photoactive Microgels for Sustainable Applications
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have synthesized and characterized PNIPAM microgels integrated with Rose Bengal as a photosensitizer, presenting their potential for use in photocatalytic applications and green synthesis of 5-hydroxy-2(5H)-19 furanone, a C4 building block intermediate. This manuscript reported a promising and innovative approach for addressing sustainability challenges in wastewater treatment and chemical synthesis. However, as the content of this study involves wastewater treatment and chemical synthesis, the focus is not prominent, so it is suggested that the authors readjust and focus on one aspect.
Comments on the Quality of English LanguageThe language writing of the manuscript needs to be improved.
Author Response
Dear Reviewer,
I hope this letter finds you well. I am writing to inform you that following your comment during the review phase, we have made several modifications to the manuscript.
The authors believe that the focus of this study is prominent, and with the aim of improving its quality, the manuscript has been significantly enhanced in terms of both the introduction and the presentation of the research results. To this end, the abstract and parts of the introduction have been rewritten, emphasizing the main objective of the study, which is to design and develop photoactive colloidal microgels for environmental applications, focusing on two key applications: the removal of pollutants and the green synthesis of sustainable materials. Similarly, the presentation of results in Section 3 (Results and Discussion) has been enhanced with additional information and a more extensive discussion to provide clearer insights into the findings.
A revised version of the manuscript, with all newly introduced or modified text highlighted in red, is included as Non-published Material. Finally, the manuscript has undergone a review to ensure the quality of the English language.
We appreciate your feedback and believe that these revisions have significantly improved the description of the objective of our manuscript.
Sincerely,
Dr. Víctor Fabregat Tena
Reviewer 2 Report
Comments and Suggestions for AuthorsDear Authors,
I have reviewed your manuscript, which presents an interesting and valuable contribution to the field of sustainable water treatment and green chemistry. Below, you will find specific suggestions aimed at enhancing the clarity, structure, and impact of the work:
ABSTRACT
- The abstract provides a comprehensive overview, but improvements are needed to enhance clarity, focus, and impact. Some sentences are too lengthy, making them harder to follow, and the main objective of the study is not explicitly stated. Redundant phrases related to sustainability and solar energy should be streamlined to make space for technical details.
- The primary objective of the study is unclear. A brief statement at the beginning should clarify whether the main goal is the development of photoactive microgels, their application in pollutant removal, or both.
- There are no concrete results presented. Consider including quantitative outcomes, such as pollutant removal efficiency (e.g., “95% Diclofenac removal in 3 hours”).
INTRODUCTION
- The introduction provides valuable context and background, but it could benefit from being more concise to improve readability and maintain focus. Consider shortening or moving some sections to other parts of the manuscript. Specifically:
- The historical overview of Green Chemistry can be summarized in a single sentence to avoid excessive detail.
- The section on lignocellulosic biomass is informative but lengthy. Consider condensing it or moving some details to a background section.
- The detailed explanation of PNIPAM-based hydrogels can be condensed, with extended details moved to the methods or a dedicated background section. Summarize their key properties and emphasize their relevance to this study in 2-3 sentences.
- The transition to Rose Bengal-supported microgels is clear but could be enhanced by explicitly stating the novel contribution of this study compared to previous work.
MATERIALS AND METHODS
- The synthesis procedure is well explained, but consider specifying the rationale for selecting the concentrations of AEMA and MBAM to highlight their impact on the final material properties.
RESULTS AND DISCUSSIONS
- This section provides a comprehensive analysis of the synthesized microgels and their performance, but some areas could benefit from improved clarity, reorganization, and the inclusion of additional details or visual elements to enhance understanding.
- (Synthesis and characterization): The section effectively introduces the synthesis and general characterization of the microgels. However, consider clarifying the link between the microgel composition (e.g., the 90:1 NIPAM-to-AEMA ratio and 9% crosslinker) and their expected performance in photocatalysis, specifically how these proportions influence key properties such as substrate adsorption, swelling behavior, and reaction efficiency. This connection would help emphasize the design rationale and its impact on the materials' functionality.
- The results on the variation of particle size and electrophoretic mobility with pH are well-presented, but consider discussing their practical relevance, particularly in identifying the optimal pH range for pollutant adsorption. Indicating how the observed pH-dependent behavior—such as changes in swelling and surface charge—supports enhanced pollutant removal in real environmental conditions would help strengthen the connection between the material properties and their environmental applications.
- The results show that Diclofenac degradation was successful, but additional discussion on potential degradation products or intermediates would strengthen this section. Consider including a brief discussion on whether any degradation intermediates (e.g., chlorinated byproducts) were detected or expected during the reaction, even if they were not characterized in detail, to provide further insight into the mechanism and environmental implications of the degradation process.
- Consider adding comparative plots, such as adsorption vs. substrate concentration and kinetic rates of microgel-anchored Rose Bengal vs. free Rose Bengal. These visual comparisons would enhance the readability and impact of the results, allowing for a clearer demonstration of the microgel’s superior performance and its role in improving photocatalytic efficiency.
CONCLUSIONS
- The conclusion effectively summarizes the key findings, but it could be enhanced by emphasizing the scalability and practical applications of the microgels in real-world wastewater treatment. Highlighting the novelty of the Rose Bengal-anchored microgels and their advantages over previous systems would strengthen the section. Additionally, mentioning potential limitations (e.g., environmental factors or long-term material stability) and suggesting future research directions, such as broader pollutant testing and recyclability improvements, would provide a more comprehensive and forward-looking conclusion.
Author Response
Dear Reviewer,
I hope this letter finds you well. I am writing to inform you that following your insightful comments and suggestions during the review phase, we have made several modifications to the manuscript. Below, you will find a detailed account of the changes we have implemented to address your concerns and to enhance the overall quality and clarity of our work. A revised version of the manuscript, with all newly introduced or modified text highlighted in red, is included as Non-published Material.
We greatly appreciate your valuable feedback and believe that these revisions have significantly improved our manuscript.
Sincerely,
Dr. Víctor Fabregat Tena
Author Response File: 
Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsThe study presents an innovative study on the synthesis and application of PNIPAM-based microgels with covalently integrated Rose Bengal as a photosensitizer. The work aligns with green chemistry principles and offers potential solutions for sustainable wastewater treatment and chemical synthesis. The research is well-structured and provides good experimental evidence supporting the effectiveness and recyclability of the synthesized microgels. However, authors need to refine certain aspects to enhance the manuscript's clarity and impact.
- The reaction kinetics and mechanistic explanations could be elaborated further. A clear comparison with existing photocatalysts (e.g., TiOâ‚‚-based systems) in terms of efficiency, cost, and performance under similar conditions would enhance the discussion.
- How does the micellar-like structure contribute to the observed rate enhancements? The role of the polymeric matrix in enhancing the photocatalytic activity needs further explanation.
- The degradation pathway of diclofenac should be discussed in more detail, possibly with supporting evidence from intermediate identification (e.g., LC-MS or GC-MS analysis).
- More information on the characterization of the microgels (e.g., FTIR, DLS, zeta potential, and TEM) is needed to support the claims regarding their structure and adsorption properties.
- While the economic simulations provide insight into scale-up feasibility, the paper should discuss potential challenges in large-scale implementation, such as material stability over prolonged use, cost of raw materials, and process optimization.
- The paper occasionally uses inconsistent terminology (e.g., ‘micellar-like’ vs. ‘colloidal structure’). Standardizing terminology would improve clarity.
- It would be beneficial to include a brief discussion on the environmental fate and toxicity of the microgels post-usage to ensure that the proposed solution does not introduce secondary contamination issues.
Author Response
Dear Reviewer,
I hope this letter finds you well. I am writing to inform you that following your insightful comments and suggestions during the review phase, we have made several modifications to the manuscript. Below, you will find a detailed account of the changes we have implemented to address your concerns and to enhance the overall quality and clarity of our work. A revised version of the manuscript, with all newly introduced or modified text highlighted in red, is included as Non-published Material.
We greatly appreciate your valuable feedback and believe that these revisions have significantly improved our manuscript.
Sincerely,
Dr. Víctor Fabregat Tena
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors have addressed all my comments so I recommend the manuscript to be accepted for publication.
