Preparation, Property Characterization of Gd₂YSbO₇/ZnBiNbO₅ Heterojunction Photocatalyst for Photocatalytic Degradation of Benzotriazole under Visible Light Irradiation

Round 1

Reviewer 1 Report

The work “Preparation, property characterization of Gd2YSbO7/ZnBiNbO5 2 heterojunction photocatalyst for photocatalytic degradation of 3 benzotriazole under visible light irradiation” present a new type of Gd2YSbO7 nanocatalyst e applied in the benzotriazole degradation . The catalyst was characterized by different techniques. In addition, it presents results of photocatalyzing, catalyst reuse, effect of different radical scavengers and reaction mechanism cycles. The work is well written and with minor revisions it can be considered for publication.

In line 63:  “biodegradation [3,4,12], adsorption [8–9,13], and flocculation- precipitation [9,11] had been utilized to degrade the 64 benzotriazole ..”  The author can be explain how the adsorption process degradate benzotriazole ? or change to remove benzotriazole

Line 65: “The photocatalysis  technology was widely used in treating sewerage due to the advantages of environmental 66 protection, high treatment efficiency and low cost [14,15].” 

Please, add water treatment not just sewage.

Is the band gap found by the direct or indirect method?

The material's photocatalytic activity in benzotriazole degradation is interesting. However, adsorption and photolysis tests should have been performed.

In particular, does radiation alone degrade the compound?

How many mL of samples were taken in the process? It is not adequated to withdraw more than 10% of the reaction volume.

What is the error of the analysis? Insert error bar.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

1. Revision 1

• Recommendation

Major Revision

2. Comments to Author

Ms. Ref. No.: catalysts-1559908

Title: Preparation, property characterization of Gd2YSbO7/ZnBiNbO5 heterojunction photocatalyst for photocatalytic degradation of benzotriazole under visible light irradiation

Ye Yao and Jingfei Luan

Overview and general recommendation:

The interesting discussion about The Gd₂YSbO₇/ZnBiNbO₅ heterojunction photocatalyst was provided. It was found that the removal rate of benzotriazole with Gd₂YSbO₇/ZnBiNbO₅ heterojunction as photocatalyst was 1.2 times or 1.3 times or 2.1 times higher than with Gd₂YSbO₇ or with ZnBiNbO₅ or with N-doped TiO₂ as catalysts after visible light irradiation of 145 minutes. Moreover, possible degradation mechanism was proposed. However, there are some drawbacks also. So, at this condition manuscript cannot be accepted for publishing. I recommend revise the manuscript according to the notes and suggestions below.

2.1. Comments

1. The number of significant figures should be revised over the manuscript. For example, 6 digits after decimal point in lattice parameter values is way to much. Of course, there were much more uncertainties. Author should write values using the criterion of reasonableness.
2. Lines 67-70. Phrase “more scientific” is a bit strange in the sentence. Please paraphrase.
3. Please correct figure 3. Ranges of x and y axes should be the same in a and b figures to compare the spectra. Moreover, what’s the reason of the noise in 300nm – 400 nm wavelengths in figure 3 a. Please explain or remeasure.
4. Figure 5 has bad quality measurements. It hinders the analysis of XPS spectra. It is not possible to identify properly oxidation states of elements. For example, O1s, Sb 4d, Bi 5d, and Nb 3d spectra are clearly not symmetrical. It is hard to perform proper fitting procedure having such kind of noise. Nevertheless, author did not do fitting procedure. It means that author did not identify all oxidation states of the elements. Please provide better quality XPS spectra and do deeper analysis of them.
5. Characterization techniques are described improperly. Please provide parameters which was used during measurements, especially for XPS, EDS, and SEM.
6. Line 673. Author states “Finally, the possible photodegradation 673 pathways for benzotriazole were speculated.” Maybe author should shortly discuss it in the conclusions also. Authors have 15 pages of results, author could include more conclusions.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

I attach word file

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

The authors revised the manuscript following the reviewers' comments. Therefore, I accept it for publication.