Review Reports

Reviewer1

Reviewer #1:

MAJOR COMMENTS

1. Rewrite the abstract. Mention key findings of the study.

We have rewritten the abstract to clearly include the main findings, such as SPF values and antimicrobial efficacy. The revised abstract now highlights the novelty and multifunctionality of our green-synthesized iron oxide nanoparticles in Pickering emulsions. [See Abstract, Page 1]

1. Update the introduction with recent literature.

The introduction section has been updated with recent literature (2023–2024), including recent green synthesis strategies and applications of metal oxide nanoparticles in skincare formulations. [See Introduction, Pages 2–4]

1. Clear novelty statement of present study in introduction is needed with literature review gaps as there are reports on green synthesis of iron oxide nanoparticles using tea extract. More emphasis should be placed on how the current study builds on or diverges from existing research.

We have added a clear novelty statement in the introduction, emphasizing that although green tea-based IONP synthesis is known, their application in multifunctional Pickering emulsions with both UV-protective and antimicrobial action is novel. [See revised Introduction, end of Page 4].

1. Mention other metal oxides (TiO₂, ZnO) synthesized using green synthesis. Some recent reports for this can be included https://doi.org/10.1016/j.chemosphere.2023.139106,https://doi.org/10.1016/j.envres.2023.116599. And highlight the importance of iron oxides over other metal oxides.

We have added comparative information on TiO₂ nanoparticles synthesized via green routes and discussed the superiority of iron oxides, particularly in blocking visible light and reducing hyperpigmentation. The suggested references have been cited. [See Introduction, Page 2]

1. Materials purity and chemical formula are not mentioned.

We have updated the "Materials" section to include the chemical formula and purity of all reagents used (e.g., FeCl₂·4H₂O ≥ 99%, Sigma-Aldrich). [See Materials and Methods, Section 2.1]

1. LCMS or GCMS spectra must be included for proper analysis for identification of phytochemicals present in the extract. Not only by FTIR spectrum.

We appreciate the reviewer’s suggestion regarding the identification of phytochemicals using LC-MS or GC-MS. However, the scope of our study focused on evaluating the feasibility of green synthesis of iron oxide nanoparticles using polyphenol-rich plant extracts, particularly with regard to the presence (rather than specific identity) of reducing and stabilizing agents. Hence, FTIR analysis was employed to confirm the functional groups associated with phenolic compounds involved in nanoparticle formation.

While we acknowledge that LC-MS or GC-MS analysis would provide detailed compound identification, such targeted profiling was not part of our experimental objective in this phase. In fact, preliminary trials were conducted using Aloe vera extract as an alternative reducing agent; however, nanoparticle formation was inefficient, which we attributed to the comparatively lower polyphenolic content of Aloe vera versus green tea extract. Therefore, green tea was selected as a more effective source of polyphenols based on its demonstrated reactivity and yield.

In future studies, we plan to conduct detailed phytochemical profiling using advanced spectroscopic techniques to better correlate specific plant constituents with nanoparticle synthesis efficiency.

1. Green synthesized nanoparticles often show clear absorbance peak in UV Vis spectra for metal oxides for their successful formation. In present study, why there is no distinct absorbance peak visible for Iron oxide Nanoparticles. Justify. And, add recent literature reports for the support also.

We appreciate the reviewer's question regarding the lack of a distinct peak in our UV-Vis spectra for green-synthesized Iron Oxide Nanoparticles (IONPs). While noble metal nanoparticles often show sharp peaks, iron oxides typically exhibit  broad absorption bands due to charge transfer and electronic transitions. Our observed broad absorbance profile is consistent with the successful formation of IONPs and is supported by recent literature, such as Flieger et al. who reported similar broad absorptions without sharp peaks for iron oxide nanoparticles.

1. Retake UV vis spectra and incorporate the band gap plot for iron oxide nanoparticles which is a key property of metal oxide for applications.

Thank you for your insightful suggestion. We have re-recorded the UV-Vis spectra of the iron oxide nanoparticles using a calibrated spectrophotometer and enhanced the resolution and clarity of the spectrum in the revised manuscript (now presented in Figure 1).

1. Figure 2, SEM images are not of good quality. The scale bars are not clear and lack sufficient resolution. Additionally, these all three SEM figures are not consistent in their dimensions. They appear visually distorted likely due to improper resizing, which results in stretching or compression. Present the figures in uniform size with well clear bar scale and other information mentioned at the bottom of SEM image.

We appreciate the reviewer's feedback regarding the quality and consistency of the SEM images in Figure 3. We acknowledge that the current resolution, clarity of scale bars, and dimensional consistency are suboptimal. We believe that SEM images of IONPs have good resolution. We appreciate the reviewer's feedback regarding the quality and consistency of the SEM images in Figure 3. We believe the current images, which were carefully captured, adequately represent the morphology of our Pickering emulsion formulations, providing clear visual evidence of their structure.

However, we understand the importance of reviewer satisfaction with data presentation. If, after further consideration, the current resolution, scale bar clarity, or dimensional consistency remain a significant concern, we are certainly prepared to acquire new SEM images to meet any higher graphical standards deemed necessary.

1. Figure 2 lacks subfigure designations (e.g., a, b, c). Improve the results section with detailed interpretation or comparison of individual SEM images.

Thank you for this comment. The revised SEM figure (Figure 3) now includes subfigure labels (a, b, c, d, e) for clarity.

1. Figure 3, is again not up to mark. Also, check the labels along X-axis and Y-axis. Present the figures in a better way as they are displaying the data of your results.

Figure 3 has wavelength as X axis and transmittance as Y axis.

1. Present well organized tables with consistency, and discuss findings with not repetition.

Thank you for pointing this out. All tables have been revised to follow a consistent format regarding font size, decimal alignment, and unit presentation. Redundant sentences and duplicate interpretations in the results section have been removed.

1. Compare antimicrobial activity to standard antibiotics or market formulations. Add one comparative table for the obtained results with literature results.

 We have indeed included standard antibiotics in our antimicrobial evaluation to provide a robust comparison for the green-synthesized iron oxide nanoparticles (IONPs) and the Pickering emulsion formulations. The Minimum Inhibitory Concentration (MIC) values for IONPs at various molarities were determined against.

Secondly, as requested, we have added a comparative discussion presenting antimicrobial results from relevant literature.

1. Figure quality is not up to mark as per journal’s standard. Pls improve Figures quality.

Thank you for your feedback regarding the figure quality. Efforts were made to enhance clarity, contrast, and consistency across all image panels. However, if any specific figures are still not satisfactory, we are willing to further revise or re-capture them to ensure optimal quality upon your guidance.

1. In conclusion emphasize broader impact, Limitations, Future research directions.

Thank you for your constructive suggestion. In response, we have revised the Conclusion section to emphasize the broader impact of our findings, particularly the potential of iron oxide nanoparticle-based Pickering emulsions as promising antimicrobial systems. We have also included a brief discussion of the current study’s limitations, such as the lack of in vivo validation and limited scope of microbial strains. The revised Conclusion section now better reflects the study’s significance and opens a perspective for future exploration.         

1. There are many typo/grammatical errors throughout the text. Proofreading for grammar and style is needed.

Thank you for pointing this out. The manuscript has been thoroughly proofread, and necessary corrections have been made to address typographical and grammatical errors throughout the text.

MINOR COMMENTS

Correct the Figure numbers. “Figure 3” is mentioned for two different figures.

Corrected.

Check for the correct labelling along X-axis or Y axis labelling in Figures.

For example: units of Temperature in Figure 5

Corrected.

Use uniform formatting for terms.

For example: Figure and Fig, both are used.

Corrected.

Missing space before citation and remove space before commas in abstract and in manuscript.

For example: Line 57: “[4], Line 69: “[7].” And also, in captions like Figure 5 etc. Please check it thoroughly.

Corrected.

Line 45: "min-imizing" is hyphenated.

Corrected.

Line 121: Hyphenation error in “Clini-cal.”

Corrected.

Line 129: Grammar issue

Corrected.

Line 161: “ex-tract” is an inappropriate split. Many more. Pls check thoroughly.

Corrected.

Line 198: “Stirred for 1 hours”. it should be “1 hour.”

Corrected.

Line 200: “adjusted 12.0”.

Bunu anlamadım.

Line 204: “in an fume hood”. it should be “in a fume hood.”

Corrected.

Line 276: Typo error: “nnaoparticles” should be “nanoparticles.”

Corrected.

Line 290: “Mansur (1984), according to This method provides a systematic approach...”. Correct it.

Corrected.

Line 297: “Only” is incomplete after sentence ends. Typo error.

Corrected.

Line 305-306: Repeated phrasing: “Following the preparation…”

Corrected.

Line 357: Sentence ends with reference but no closure and unclear phrasing. Also, no space before citation.

Yaptım ama tekrar bak.

Line 453: “Measurements were continued…” a vague passive voice.

Corrected.

Line 460: “aesthetic applicability” needs clarification.

Corrected.

Line 574: “…..microbial standart strains.” Correct.

Corrected.

Table 3: formatting is misaligned.

Sağa hizalandı.

Table 4 caption, all the letters of each word are capital.

Table 4, Abbreviation unclear (e.g., “sçk”).

Corrected.

Line 641-643: correct the sentence “However…..application time results”.

Corrected.

Line 659: Grammar issue. “These findings need for further exploration…”. Incorrect structure. It should be: “These findings highlight the need for further exploration…”

Corrected.

Bacteria name should be italic throughout the manuscript.

We checked.

Abbreviations must be defined at the first and should be uniform. For example: IONP or IONp etc. Please thoroughly check.

Corrected.

Reviewer2

Reviewer #1:

The manuscript describes that iron oxide nanoparticles-based Pickering emulsion for sun protective effect and antibacterial effect.

The antibacterial activity of the green tea-mediated iron oxide nanoparticles was also evaluated against various bacterial strains, demonstrating significant antimicrobial properties, which can be attributed to the combined effects of the nanoparticles and the bioactive compounds in the green tea extract.

Detailed background information about the significance of this work is provided.

The manuscript has enough data, and the tests are done in good positions. The scope is adequate, and the methods are appropriate.

The topic in discussion is appealing since it has the potential to offer sun protective and antibacterial effect. Therefore, I highly recommend accepting the manuscript for publication once the authors have considered the following comments:

I highly recommend accepting the manuscript for publication, The results are useful, and I think after minor revision it is suitable for publishing.

1.The introduction, in 7Th paragraph the information could be stated in the discussion of the results.

We added.

2.And some examples exposed along the introduction could be summarized in a table.

Thank you for your suggestion. Instead of summarizing the examples in a table, we have expanded the relevant sections of the Introduction to provide more detailed context and explanation for the examples discussed. This approach was intended to preserve the narrative flow while enhancing clarity for the reader. However, if preferred, we would be happy to present these examples in a summarized table format in the revised manuscript.

3.There are some spelling mistakes (e.g. line 577 “solition” correct to solution; line 275 “according” correct to according;

Corrected.

Reviewer3

Reviewer #3:

The authors' work concerns the potential applicability of iron oxide nanoparticles in cosmetics due to their UV filtering and antimicrobial properties. However, the work lacks several considerations and data. For example, there is no mention of European Cosmetic Regulation 1223/09, which only authorizes filters listed in Annex VI. Additionally, there is no discussion of the limited number of authorized filters in the U.S. (which has an even more restrictive annex).

Iron oxide is allowed as colorant in Annex IV. The main purpose was to evaluate the viability before the commercialization.

Iron oxide is not included in either list. Therefore, a study of the SPF of a preparation containing nanoparticulated iron oxide is not useful because it cannot currently be used as a UV filter. Moreover No UV spectra are present to confirm the filtering ability of the nano scale oxide obtained.

Iron oxide is allowed as colorant in UE.

Despite the American Academy of Dermatology's recommendations regarding sunscreen products and the and the strict guidelines associated with safety of cosmetic ingredients  , the authors make no mention of the hazardousness of nanoparticles included in formulations. There are few parallels between authorized inorganic nanoparticulate filters, such as titanium dioxide, at least in Europe. The authors only report on physical screeners, and their discussion is not exhaustive.

We thank the reviewer for this important comment regarding the safety and regulatory aspects of nanoparticulate ingredients in topical formulations. Indeed, the potential toxicity and regulatory approval of nanomaterials, especially when intended for skin application, remain central concerns in dermatological and cosmetic science.

In our study, we utilized green-synthesized iron oxide nanoparticles (IONPs) as physical UV-screeners within a Pickering emulsion system. While titanium dioxide (TiO₂) and zinc oxide (ZnO) are the most widely authorized inorganic UV filters in both the EU and the US, iron oxide particles are also permitted for use in cosmetics, primarily as colorants and also contributing to photoprotection in certain formulations (e.g., tinted sunscreens).

We acknowledge that our original manuscript did not sufficiently address the toxicological profile or regulatory status of IONPs. In response, we have now included a dedicated subsection in the revised manuscript to introdoction part:

Iron oxides (Fe₂O₃, Fe₃O₄), including their nano-sized forms, are permitted cosmetic ingredients and are primarily regulated as colorants (CI 77491, CI 77492, and CI 77499) in both the European Union (EU) and the United States (US). Although they are not explicitly approved as UV filters under current regulations, they are frequently used in tinted sunscreens, foundations, and BB creams to provide both coloration and photoprotection, particularly against visible and blue light[10-13].

In the EU, iron oxides are listed in Annex IV of the EU Cosmetics Regulation (1223/2009/EC), which covers approved colorants. The regulation does not restrict particle size, meaning that nano-forms are implicitly allowed, provided that they are safe and non-penetrative. However, manufacturers must demonstrate safety through a Cosmetic Product Safety Report (CPSR), particularly for nano-materials. In summary, while iron oxide nanoparticles are not classified as primary UV filters like titanium dioxide or zinc oxide, their use as secondary photoprotective agents and colorants is well-established and permitted in topical cosmetic formulations, provided that safety is demonstrated. Their inclusion in formulations, especially those based on green synthesis methods, aligns with the principles of safer-by-design nanomaterials.

We acknowledge the reviewer’s concern regarding the potential hazardousness of nanoparticles used in topical formulations. As noted, the regulatory framework for nanomaterials in cosmetics—especially those not explicitly listed as primary UV filters—requires careful safety assessment.

In this context, and considering the importance of biocompatibility, we also conducted in vitro cell culture studies to assess the cytocompatibility of our green-synthesized iron oxide nanoparticles (IONPs). These tests were performed to preliminarily evaluate their potential safety for topical application. Our results indicated no significant cytotoxic effects at the tested concentrations, supporting their safe use in cosmetic systems, particularly when incorporated in Pickering emulsions.

No data were obtained or provided on the cytotoxicity of the synthesized particles. A lack of data exists to support the claim regarding the environmental sustainability of the procedure used to obtain the particles.

We performed the cytotoxicity testing (Section 2.10).

No data regard  yields (FeCl₂ conversion) of obtained  nanoparticles, no data on the determination of their size, size distribution, etc.   

While we acknowledge that the conversion yield of FeCl2 was not explicitly quantified in this study, we have included comprehensive data on the size and size distribution of the obtained nanoparticles through Dynamic Light Scattering (DLS) and Scanning Electron Microscopy (SEM). In our manuscript, we report that DLS measurements

The microbiological studies, particularly the MIC, are not appropriate in this case. The MIC involves testing a solution to observe ; however, in this case, the iron oxide particles are not soluble in the medium.

You are absolutely correct, and we appreciate the reviewer's astute observation regarding the limitations of the Minimum Inhibitory Concentration (MIC) method for our insoluble iron oxide nanoparticles (IONPs).

We acknowledge that the traditional MIC method, which relies on observing turbidity in a solution, is indeed not fully appropriate for assessing the antimicrobial activity of insoluble particles such as our IONPs. This challenge was encountered during our initial antimicrobial investigations. Consequently, to accurately evaluate the antimicrobial efficacy of our insoluble IONPs, we adopted a two-pronged approach. Initially, we focused on determining the MIC values of the bare iron oxide nanoparticles. Recognizing the inherent limitation due to the insolubility of IONPs in the medium, we then proceeded with a more suitable method for our final Pickering emulsion formulations.

For these formulations, we employed the  AATCC 100 test method. This method, a standard quantitative procedure for assessing the antimicrobial activity of textile materials, is highly appropriate for insoluble and turbid formulations like our Pickering emulsions, as it directly measures the reduction in microbial count after contact. This dual-method strategy allowed us to overcome the solubility challenge and provide a more relevant assessment of our formulations' antimicrobial performance.

In summary, although the approach may be considered intriguing for the purpose of evaluating oxide nanoparticles as potential boosters in solar emulsions, the work exhibits a certain degree of scientific inconsistency.

Reviewer4

Reviewer #4:

The introduction is great but a little chaotic. I strongly recommend for the authors to better organize the ideas in a better flow.

280 - please include in vitro at the title

Added.

Figure 3 - low resolution. Please include both graphics in the same image or at least use the same scale for the y-axis.

We appreciate the reviewer's valuable feedback regarding Figure 3 and the resolution/scaling of the FT-IR spectra.

We acknowledge that presenting both graphics within the same image or using a unified y-axis scale would enhance clarity and comparability, as suggested. Unfortunately, due to the technical specifications and output capabilities of our current FT-IR instrument (Perkin Elmer Spectrum 100), we were limited to the separate, individual spectrum captures provided. Obtaining a single image with a unified scale directly from the instrument's software was not feasible.

We understand the importance of high-quality data presentation. If the current representation remains a significant concern, we are prepared to conduct new FT-IR measurements using an alternative instrument to meet the requested graphical standards

There are two figure 3 in the paper, please correct

Corrected.

Please provide a shear stress vs shear rate graphic for your formulation.

Added.

Why your synthesis is "green"? I missed a little about this topic being discussed or compared with other studies, for example.

We appreciate the reviewer's comment regarding the "green" nature of our synthesis method and its comparison with other studies. We acknowledge that this aspect might not have been sufficiently emphasized or directly compared in detail with alternative synthesis methods in our initial submission. We would like to clarify why our approach is considered "green" and how it stands in comparison to conventional methods and other green synthesis techniques discussed in the literature.

Our synthesis method for iron oxide nanoparticles (IONPs) is explicitly "green" due to the utilization of antioxidant-rich green tea extract as both a reducing and stabilizing agent. This approach fundamentally diverges from traditional chemical synthesis methods that often involve toxic chemicals and harsh conditions. The polyphenolic compounds, such as catechins, present in green tea, play a crucial role in the reduction of ferric ions (Fe³⁺) into IONPs and subsequently stabilize the nanoparticles. This process minimizes environmental impact and enhances the biocompatibility of the synthesized nanoparticles.

In comparison to other studies, our method aligns with the growing trend of eco-friendly nanoparticle synthesis. For example, similar green synthesis approaches have successfully utilized various plant extracts like sorghum bran, Chlorella-K01, and microalgal extracts for iron nanoparticle synthesis. The core principle of these methods, including ours, is to reduce environmental impact and provide a cost-effective and sustainable alternative to traditional chemical methods. While some studies, like Flieger et al. (2024), discuss mixed-mode chemical/biogenic synthesis using plant extracts, our method specifically focuses on the complete replacement of conventional chemical reducing and stabilizing agents with green tea extract. This positions our synthesis as a truly "green" approach, emphasizing sustainability from the outset. Furthermore, unlike some "green" methods that might enhance cytotoxicity, our approach uses green tea extract, which is known for its anti-inflammatory and antimicrobial effects, supporting its potential for topical skincare formulations and acting as a chemoprotectant and sunscreen agent.

Why did the authors selected green tea extract? Did the authors performed antioxidant tests?

We initially attempted to use aloe vera extract in the synthesis of iron oxide nanoparticles (IONPs); however, the production yield was considerably low. Therefore, we opted for green tea extract (Camellia sinensis) due to its well-documented high antioxidant capacity and its UV-protective (sunscreen) properties, both of which are crucial for our intended application in Pickering emulsions with potential topical uses. The polyphenolic content in green tea, particularly catechins such as epigallocatechin gallate (EGCG), is known to facilitate efficient nanoparticle synthesis by acting as a reducing and capping agent.

Moreover, several studies have confirmed the antioxidant-rich profile of green tea extract, making it a superior candidate compared to aloe vera in terms of reducing power and nanoparticle stabilization:

-Farrar, M. D., Nicolaou, A., Clarke, K. A., Mason, S., Massey, K. A., Dew, T. P., … & Rhodes, L. E. (2015). A randomized controlled trial of green tea catechins in protection against ultraviolet radiation–induced cutaneous inflammation. The American Journal of Clinical Nutrition, 102(3), 608-615. https://doi.org/10.3945/ajcn.115.107995

-Yusuf, N., Irby, C., Katiyar, S. K., & Elmets, C. A. (2007). Photoprotective effects of green tea polyphenols. Photodermatology, Photoimmunology &Amp; Photomedicine, 23(1), 48-56. https://doi.org/10.1111/j.1600-0781.2007.00262.x

-Seeram, N. P., Henning, S. M., Niu, Y., Lee, R., Scheuller, H. S., & Heber, D. (2006). Catechin and caffeine content of green tea dietary supplements and correlation with antioxidant capacity. Journal of Agricultural and Food Chemistry, 54(5), 1599-1603. https://doi.org/10.1021/jf052857r

In our study, while we did not perform specific antioxidant assays such as DPPH or FRAP, the selection of green tea extract was based on these well-established findings in the literature and the observed superior synthesis efficiency compared to aloe vera.

What`s the central idea to apply rheology for your study?

The core reason for conducting rheological analyses on our Pickering emulsion formulations is to comprehensively understand their mechanical and viscoelastic properties, which are critical for both formulation stability and potential application performance. Unlike traditional emulsions, Pickering emulsions are stabilized by solid particles, giving them unique flow characteristics that directly impact their aesthetic appeal, spreadability on the skin, and overall usability as a cosmeceutical product.

Why the suthors decided for Pickering emulsions?

We decided to use Pickering emulsions for their unique advantages these emulsions offer over traditional surfactant-stabilized systems, especially in the context of developing multifunctional cosmeceutical formulations.

If we can count them

-The use of solid particles eliminates the need for traditional surfactants. This is advantageous as conventional surfactants can sometimes cause skin irritation, phototoxicity, or environmental concerns.

-The chosen IONPs not only act as stabilizing agents for the emulsion but also contribute additional functionalities. They provide strong UV absorption for sun protection and exhibit intrinsic antimicrobial activity. This dual-functional system is a central idea of the study.

-Using particles like green-synthesized IONPs and natural ingredients such as coconut oil and green tea extract for stabilization fits well within a sustainable and eco-friendly framework.

-The interfacial layer formed by the nanoparticles in Pickering emulsions provides a physical barrier against UV radiation, reducing its penetration into the skin.

Could you explain about the importance of your particles in face of other available particles?

We aimed to investigate the alternative properties of materials like TiO₂ and ZnO. Our goal was to enhance the sun protective effects of substances already used in cosmetics. We also aimed to produce healthy and environmentally friendly products by utilizing green tea extract and coconut oil in green synthesis.

How is the final color from your formulations? Sensorial perception of color/white casting is an important observation for cosmetic industry.

The final emulsion formulation exhibited a characteristic brownish color due to the iron oxide content. The study acknowledges that this color may pose a challenge for its acceptance in cosmetic or dermatological topical formulations, where product appearance and consumer preference for clear or skin-toned products are often critical for market appeal.

Reviewer1

Reviewer #1:

MAJOR COMMENTS

1. Figures1-4 are of not poor quality. It was suggested previously also. Authors should plot the data in "Origin" or any other software for proper visibility ad uniform size. Don't include the poor quality pictures taken or obtained by instrument.

Figures 1–4 have been revised to ensure high resolution, improved visibility, and uniform sizing across all graphics. All figures have been exported at min 300 dpi to comply with publication standards.

1. Incorrect the label-spellings or missed labels along X-axis in Figures 1, 2, 4.

For example: incorrect label spelling in Fig 1, also no units.

X-axis labels and units have been carefully revised in Figures 1, 2, and 4. Spelling errors have been corrected, missing units have been added, and proper scientific notation (e.g., superscripts such as cm⁻¹) has been applied.

1. Figure 4: No label along X axis. Also, No proper superscript in units.etc.

Figure 4 has been corrected to include an appropriate X-axis label with correct units and superscript formatting.

1. Similarly, the SEM images no scale is visible which is very important for analysis, suggested perilously.

SEM images (Figure 3) have been updated to include clearly visible scale bars in all subfigures.

1. Still these all SEM figures are not consistent properly in their dimensions. They appear visually distorted likely due to improper resizing, which results in stretching or compression.

We appreciate the reviewer’s observation. The apparent inconsistency in dimensions among the SEM subfigures is due to the use of different magnification ratios (e.g., 1,000×, 20,000×, and 100,000×) to capture distinct morphological features of the nanoparticles and emulsion structure. This approach was intentional to provide a comprehensive visualization—ranging from general surface distribution to detailed particle-level morphology.

1. Additionally, the font size of text (Figure 6) and Curve (data line) size in Figure 6 is too large as compared to other figures. The labels must be uniform in all figures.

Figure 6 has been adjusted to reduce the font size of axis labels and the thickness of data curves. All font styles and sizes are now consistent across all figures to maintain a uniform presentation.

1. No explanation of some individual Figures (a,b,c etc) in the text, as previously suggested.

Finally, a detailed explanation of each individual SEM subfigure (Figure 3a–e) has been incorporated into the main text, as previously suggested.