Photoluminescent and Photocatalytic Properties of Eu3+-Doped MgAl Oxide Coatings Formed by Plasma Electrolytic Oxidation of AZ31 Magnesium Alloy
Round 1
Reviewer 1 Report
This article reports, Photoluminescent and photocatalytic properties of Eu3+ doped MgAl oxide coatings formed by plasma electrolytic oxidation of AZ31 magnesium alloy. Author investigated the Photoluminescent and photocatalytic properties in detail. However, following revisions should be made before publication.
Highlight the novelty of this work in abstract and introduction section. The writing skills is very poor and some explanations are improper.
In Figure 4, JCPDS file should be updated in the XRD patterns.
In introduction section, the importance of layered double hydroxides should be elaborated with the integrity of following articles: doi.org/10.1016/j.cej.2021.129312, doi.org/10.1016/j.cej.2021.132345, doi.org/10.1016/j.jechem.2021.05.002, doi.org/10.1016/j.seppur.2022.120463.
Please provide real time FESEM EDS mapping.
Author Response
This article reports, Photoluminescent and photocatalytic properties of Eu3+ doped MgAl oxide coatings formed by plasma electrolytic oxidation of AZ31 magnesium alloy. Author investigated the Photoluminescent and photocatalytic properties in detail. However, following revisions should be made before publication.
Highlight the novelty of this work in abstract and introduction section. The writing skills is very poor and some explanations are improper.
Answer: Thank you for this comment. We have corrected abstract and introduction according to the suggestion of reviewer.
In Figure 4, JCPDS file should be updated in the XRD patterns.
Answer: Reference JCPDS cards and graphics which were used to identify reflections on XRD patterns are added in Figure 4.
In introduction section, the importance of layered double hydroxides should be elaborated with the integrity of following articles: doi.org/10.1016/j.cej.2021.129312, doi.org/10.1016/j.cej.2021.132345, doi.org/10.1016/j.jechem.2021.05.002, doi.org/10.1016/j.seppur.2022.120463.
Answer: Double hydroxide layers are not in the focus of this work. The resulting coatings consist of MgO and MgAl2O4.
Please provide real time FESEM EDS mapping.
Answer: Unfortunately, in our institution we do not have a device on which we could perform real time FESEM EDS mapping.
Reviewer 2 Report
The authors fabricated Eu3+ doped MgAl oxide coatings containing MgO and MgAl2O4 and investigated their photoluminescent and photocatalytic properties. The manuscript was very well written and the logic is consistent. I recommend the publication of this manuscript in Coating after minor revision.
1. I think it is better to add a result of PA without the irradiation of light in Figure 8a to check the self-degradation rate of methyl orange.
Author Response
The authors fabricated Eu3+ doped MgAl oxide coatings containing MgO and MgAl2O4 and investigated their photoluminescent and photocatalytic properties. The manuscript was very well written and the logic is consistent. I recommend the publication of this manuscript in Coating after minor revision.
1. I think it is better to add a result of PA without the irradiation of light in Figure 8a to check the self-degradation rate of methyl orange.
Answer: Thank you for this comment. We conducted self-degradation tests but did not include them in the paper. The results of the self-degradation test for the most active sample are now shown in Figure 8a.
Reviewer 3 Report
The article by Stevan Stojadinović et al. is very interesting and worth publishing. The article creates a favorable viewing experience and contains valuable information about the luminescence of the europium ion in the material. But it contains very little data on the photocatalytic properties of the material. Almost nothing about photocatalysis. Then the mention of photocatalysis should have been removed from the title. Figure 2 contains a lot of panels, their number should be reduced to 6 at least. Panels (a) and (b) in Figure 9 are very similar and one of them should be removed, or two types of data should be presented in one panel. Fig.1. may be removed from the article without any loss of understanding. The two spectra in Figure 10d should not be vertically shifted relative to each other, but rather superimposed on each other to reveal differences in them. If there are no differences, then this figure is not necessary. Eight illustrations would be enough for this work. Minor revision is necessary for this manuscript.
Author Response
The article by Stevan Stojadinović et al. is very interesting and worth publishing. The article creates a favorable viewing experience and contains valuable information about the luminescence of the europium ion in the material. But it contains very little data on the photocatalytic properties of the material. Almost nothing about photocatalysis. Then the mention of photocatalysis should have been removed from the title. Figure 2 contains a lot of panels, their number should be reduced to 6 at least. Panels (a) and (b) in Figure 9 are very similar and one of them should be removed, or two types of data should be presented in one panel. Fig.1. may be removed from the article without any loss of understanding. The two spectra in Figure 10d should not be vertically shifted relative to each other, but rather superimposed on each other to reveal differences in them. If there are no differences, then this figure is not necessary. Eight illustrations would be enough for this work. Minor revision is necessary for this manuscript.
Answer: Thank you for your affirmative response. We think that the mention of photocatalysis should remain in the title because the results show that a very good photocatalyst can be obtained by the PEO processing of AZ31 in electrolyte containing Eu2O3 particles. We have removed Figure 1 from the amended manuscript. In current Figure 1 we reduced the number of panels to 5 (SEM images only). Figure 3 now shows SEM/EDS analysis for only one sample. Panels (a) and (b) in Figure 9 are very similar, but they differ in intensity. We have left only Figure 9c in the revised text which shows the intensities at the maximum emission wavelength of 425 nm. We have also removed Figure 9d.
