Ultrasound Assisted Synthesis of Gadolinium Oxide-Zeolitic Imidazolate Framework-8 Nanocomposites and Their Optimization for Photocatalytic Degradation of Methyl Orange Using Response Surface Methodology

Round 1

Reviewer 1 Report

The paper  presents interesting results. However few things must be corrected:

1) In the introduction there is lack of information why it was chosen to produce Gd₂O₃-ZIF-8 composites. And also there are no information are such composites investigated by someone or its first time when such composites were produced. it mus be corrected.

2) From the introduction section it is not clear what the main goal of the paper is. Is it RSM experiment based on BBD or synthesis of nanocomposites or both. It must be corrected.

3) In the results and discussion there is lack of the explanation why XRD diffraction, Raman spectroscopy and Scanning electron spectroscopy was used. For what purpose such measurements were conducted and what conclusions were made from each of them and final cocnlusions from all of these measurements. It mus be corrected.

4) It is not clear how it was determined from Figure 3 that Gd₂O₃ nanoparticles are nanowire-like. It is also misunderstanding in term "nanowire-like nanoparticles". So is it nanoparticles or nanowires in the figure?

5) It is suggested to change paragraph name " 3.2 Methods" into "3.2 Measurement methods" as its more clearly represent what is presented in that paragraph.

 

Author Response

Dear Reviewer 1 

How are you these days?

MS number : Catalysts-1336666

I have revised manuscript contents (as red color) by reviewer’s comments.

I sent the revised manuscript and answer sheet for reviewer's comments to you. 

I look forward to hearing good news soon.

Thanks.

Sincerely Yours,

From Prof. Weon Bae Ko 

Department of Chemistry 

Sahmyook University 

815, Hwarang-ro, Nowon-gu, Seoul, 01795

South Korea

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors presented an interesting work regarding the photocatalytic activity of Gd2O3-ZIF-8 nanocomposites along with RSM optimization. While the results seemed to be attractive, some revisions are required before publication.

1. Light absorption properties should be measured to identify whether the absorption band of samples corresponds to the light irradiation (254 nm).
2. The role of each component should be identified, including Gd2O3 and ZIF-8, with experimental evidence.
3. Please confirm the morphology of Gd2O3 and revise the way to describe them, nanoparticles or nanowires.
4. In addition to apply the first-order kinetic model, it is better to investigate another frequently used one, second-order kinetic model. Please refer to and cite the following reference: Nanoscale Res. Lett., 14, 244 (2019).
5. The reviewer suggests that the discussion in section 2.4 is inappropriate, because the photocatalysts own the color. In this regard, the extent of aggregation of used photocatalysts also affect the color change.
6. In table 3, please present how to evaluate the predicted degradation percentage in detail.
7. When apply RSM method to optimize the photocatalytic activity, the authors should state clear the range of each parameters. For example, the authors claimed that the pH and MO concentration negatively affected the photocatalytic degradation of MO, whereas this statement may be wrong if the pH values are very high or low. Same issues appear in MO concentration. More experimental evidences should be done to find out the appropriate range of each tested parameters.
8. The light intensity of irridated light should be presented.

Author Response

Dear Reviewer 2

How are you these days?

MS number : Catalysts-1336666

I have revised manuscript contents (as red color) by reviewer’s comments.

I sent the revised manuscript and answer sheet for reviewer's comments to you. 

I look forward to hearing good news soon.

Thanks.

Sincerely Yours,

From Prof. Weon Bae Ko

Department of Chemistry

Sahmyook University

815, Hwarang-ro, Nowon-gu, Seoul, 01795

South Korea

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have done the adequate revisions, and the manuscript is ready for publication. 

Author Response

Thank you for your careful review of my manuscript.