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★ ★ ★ ★ ★
ljl1205(金币+5,VIP+0): 9-13 11:50
Reviewer 2
1. “Although they studied several factors that influence the shape, size and crystalline structure of the obtained nanoparticles, no investigation of functional properties were reported, no even for those samples with well-crystallized, monodispersed structure and anisotropic like Figure 3F, 6A,B,C and 8C. Not to mention that the residues from PVP thermal decomposition affect the catalytic properties of nanoparticles, making the comparison inadequate.”
In this work, two representative functionalities, for example magnetic property and catalytic ability in CO oxidation of hematite nanodiscs have been investigated, as discussed in Section 3.4. However, this work focuses on the controllably synthesis of hematite nanostructures with different shapes and sizes. As correctly pointed out by this referee, it only has a limited effort in exploring the functional properties. To avoid possible confusion or misunderstanding, the title of this paper has been changed to “Synthesis and Growth of Hematite Nanodiscs through a Facile Hydrothermal Approach”.
2. “Figure 2C,D can not be seen.”
This may be caused by the poor resolution of the PDF converted image. In order to see clearly, the resolution of the two figures has been improved in the revised version.
3. “Figure 9A,B are not clear enough.”
To see clearly, the line style and point size in Figure 9A,B have been improved in the revised version.
Reviewer 5
1. “P2L11 states that some methods of the published studies focused on the thermal decomposition of organometallic precursors, which limit their applications. But, there is no reasons provided. Brief mention of the reasons is necessary.”
As suggested, the reason is briefly mentioned in Paragraph 1, page 2, as below:
“For example, the iron oxide nanoparticles obtained by thermal decomposition in non-polar solvents are difficult directly to be transferred into aqueous solution due to the surface coated surfactants. The removal of such surfactants may lead to particle aggregation, and hence affect the covalently binding other surfactants such as poly(ethylene)glycol (PEG) spacer with hydrophilic groups for further dextran coating that is targeted toward solid tumor treatment (Sonvico et al. 2005). ”
2. “In Fig. 1 and Fig. 6, the author should give the measurement method (histogram figure of size distribution) and explain the measured procedure. In addition, for Fig. 4, the author gives the range of size distributions. I want to know the measured procedure”
The data for particle size distribution were collected based on TEM analysis, and also assisted by the Image Processing and Analysis Program (ImageJ 1.37v, 2006). This has been added in the revised version in Section 2.2 Characterization (Page 4).
3. “P6L6, the author think that the nucleation is fast while the subsequent growth seems slow in this synthesis process by heating for different time. This explanation is not convincible. I don't see this point from Fig. 3. The nucleation and the growth may be overlapped each other. The author may wish to describe the "burst-nucleation"mechanism.”
As suggested, the nucleation and growth mechanism of the iron oxide particles is re-discussed in the revised version (Page 6), as below:
“This result suggested that the nucleation is fast, namely, the so-called “burst-nucleation” happens in this reaction system. Despite the nucleation and the growth may be overlapped each other at the initial stage, the particle size increases with time could be clearly observed after 5 min (Fig. 3B-F). The fast nucleation and the subsequent slow growth to be well-crystallized nanodiscs could also be confirmed by the relationship between reaction time and particle sizes, as described in Fig. 4, in which the data were collected and compared on the basis of TEM images obtained at different times. This is different from the nucleation delayed mechanism occurred in the formation of iron oxide nanodiscs through the thermal decomposition of Fe(CO)5 precursor in non-polar solvent (Casual et al. 2006).”
4. “P9L28, "Seen from the TEM images (Fig. 6, panels A-C), some of particles overlapped as pointed by arrows, suggesting that disclike structure may be formed, as discussed above". Some of particles overlapped are universal situations in TEM images of nanoparticles. The point should not be used as a proof of the formation of disclike structure.”
As suggested, the sentence "Seen from the TEM images (Fig. 6, panels A-C),… as discussed above." has been deleted, and the arrows have been removed from Fig. 6B in the revised version.
5. “I don't see the irregular particles with diameter of 5-10 nm in Fig. 7A (a lack of resolution). It must be re-worked.”
Done as suggested.
6. “P11, "at a very low concentration of [Fe3+] (e.g., 0.038 mM), hollow nanostructures were prepared". It is very interesting. Can the author give the reason or the formation mechanism.”
As suggested, the possible mechanism to the formation of hollow nanostructures has been discussed in the revised version (Paragraph 1, Page 12), as below:
“Further observation from the magnification TEM image in the insert of Fig. 8F reveals that the hollow or porous structures are composed of small particles, which possible self-assemble into big spheres with pores through the electrostatic and/or van der Waals forces. The formation process is similar to the literature, in which the porous hematite nanostructures (e.g., rings, tubes, porous rods) were prepared through template-free solution-based synthesis, and the investigators addressed the key role of the ions in the formation of (Wen et al. 2005; Wu et, and Cl, SO42hollow/porous structures, such as H2PO4 ions probablyal. 2006; Jia et al. 2007; Gou et al. 2008). In this case, the Cl play an important role of in the formation of such nanostructures. However, the nature is still not clear. Therefore, more work needs to be performed for understanding the hollow structures.”
7. “The author should insert a space between numbers and units. Such as page 8(ionic radius 1.8Å . Similar corrections should also be done in the paper.”
Done as suggested.
8. “P7, "by Casula et al (2006)-", Page9, "literature.18", Page 13, "temperatures (Zhang et al. 2004).30 ". These mistakes of format should be corrected in the paper.”
Done as suggested. |
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