Lithium Polysulfide Catalytic Mechanism of AlN/InN Heterojunction by First-Principles Calculation

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Fugen et.al reported the Lithium polysulfides catalytic mechanism of AlN/InN hetero-junction: By First-principles calculation. The reports include the effect of heterojunction on polysulfide adsorption and its catalysis reaction.  The overall manuscript covers very few technical aspects and hence manuscript requires major revision. The comments are as follows.

 

 

1.     Bader charge analysis shows that InN will get more electrons compared to AlN in heterojunction. What is the driving force behind InN to receive more electrons? 

 

2.     Why does AlN have more absorptivity characteristics towards various LiPS compared to InN?

 

3.     How did the authors conclude rate determining step based on adsorption? The rate-determining step can vary based on various reaction parameters. Authors need to be specific and discuss more on this.

 

4.     How would be catalytic activity of heterojunction compared to the individual nitrides? what materials properties changes can be expected to drive effective LiPS catalytic transformation mechanisms. Need more details on that. 

 

5.     Overall, need to discuss more in technical detail about the results. 

 

 

 

 

 

 

 

 

 

 

 

Comments on the Quality of English Language

moderate english editing required for better understanding.

Author Response

Dear editor,

We deeply appreciate for the constructive suggestions. According to editor’s questions, our reply is follow as:

 

1. Bader charge analysis shows that InN will get more electrons compared to AlN in heterojunction. What is the driving force behind InN to receive more electrons? 

Answer:  the electron transfer will form built-in electric field in the two-phase interface due to the existence of band gap offset. Better conductivity enables InN to receive more electrons.

2. Why does AlN have more absorptivity characteristics towards various LiPS compared to InN?

Answer: the built-in electric field will form electronic-rich and electronic-deficient sites in heterojunction, which can improve the adsorption capability of LiPSs. In AlN side, there are more electronic-rich sites that is favorable for the adsorption of Li+.

3. How did the authors conclude rate determining step based on adsorption? The rate-determining step can vary based on various reaction parameters. Authors need to be specific and discuss more on this.

Answer: For calculated system, the Gabbs gree energy is roughly equal to the adsorption energy. The calculation fomula of the reaction Gibbs free energy has been added in manuscript.

4. How would be catalytic activity of heterojunction compared to the individual nitrides? what materials properties changes can be expected to drive effective LiPS catalytic transformation mechanisms. Need more details on that. 

 Answer: The catalytic activity of heterojunction has been widely discussed through experiments and theoretical calculations, for example J.Mater.Chem. A 10, 939-949 (2022), Small 19, 2206462 (2023), Small, 2309422 (2024) et al.. We want to clarify which polysulfide is transferring from one side of the heterojunction to another side. Comparing free energy profiles individual nitrides AlN and InN (as shown in inset Fig.4), it can be obtained that the reduction process from S₈ to Li₂S₆ is thermodynamically more favorable on AlN surface than InN and it is more favorable for InN during the reduction from Li₂S₄ to Li₂S₂. So Li2S4 is transfered from one side of the heterojunction to another side. This confirms the synergistic effect of AlN and InN. AlN traps large Li₂S₈ and Li₂S₆, junction forms diffusion of Li₂S₄ and InN completes the conversion of Li₂S₄ to Li₂S, which realize the synergistic reaction of trapping-diffusion-conversion for LiPSs in the surface and interface of catalytic agent.

 

5. Overall, need to discuss more in technical detail about the results. 

Answer: More migration details can theoretically be achieved through molecular dynamics simulations, but the Li2S4 molecule is too large to realize at present, and then we need to continue our efforts.

 

Thanks!

 

Your sincerely!

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

In this article by first-principles calculation was studie Lithium polysulfides catalytic mechanism of AlN/InN heterojunction.

In general, the manuscript of the article is well written, has novelty, has a clear and complete structure, it can be accepted for publication, but in my opinion, it needs minor clarifications.
To begin with, I will indicate that I checked the version "catalysts-2971657-peer-review-v2.pdf".

1. In Figures 1, 2, 3, 5, the structures of AlN and InN are shown in two colors, blue and pink. It is expected that they will keep this order until the end, but in different pictures the colors correspond to different structures. So it needs to be checked. Or sign each structure, as is already done in Figure 5.

2. On page 5, in the phrase "as shown in Fig.S1." error or need clarification. Maybe only "... Fig.1".

3. On page 6, in the phrase "Fig.5c shows three diffusion paths..." why are only 3 paths selected? What are other possibilities, and if they are possible, indicate why they were not considered? 

Also, in the figure "Fig.5c" draw the lines of the paths more clearly, because they are not visible enough.

 

Author Response

Dear editor,

We deeply appreciate for the constructive suggestions. According to editor’s questions, our reply is follow as:

1. In Figures 1, 2, 3, 5, the structures of AlN and InN are shown in two colors, blue and pink. It is expected that they will keep this order until the end, but in different pictures the colors correspond to different structures. So it needs to be checked. Or sign each structure, as is already done in Figure 5.

Answer: the color of Figure 4 has been revised.

2. On page 5, in the phrase "as shown in Fig.S1." error or need clarification. Maybe only "... Fig.1".

Answer: Fig.S1 is following figure, which is differential charge densities. And this figure has been added in the paper as Fig.5.

 

3. On page 6, in the phrase "Fig.5c shows three diffusion paths..." why are only 3 paths selected? What are other possibilities, and if they are possible, indicate why they were not considered? 

Answer: Three paths are chosed based on the principle of passing through the junction as soon as possible and neighbor transfer.

 

Also, in the figure "Fig.5c" draw the lines of the paths more clearly, because they are not visible enough.

Answer: it has been revised.

Thanks!

 

Your sincerely!

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The authors adequately addressed the reviewer's comments. However, the Reviewer feels that technical discussion still can be improved in the manuscript and can be accepted after minor revision.

Comments on the Quality of English Language

it is difficult to understand a few places and may need rephrasing the sentences for better understanding. 

Author Response

We deeply appreciate for the constructive suggestions. According to editor’s questions, our reply is follow as:

 

1. Bader charge analysis shows that InN will get more electrons compared to AlN in heterojunction. What is the driving force behind InN to receive more electrons? 

Answer:  the electron transfer will form built-in electric field in the two-phase interface due to the existence of band gap offset. Better conductivity enables InN to receive more electrons.

2. Why does AlN have more absorptivity characteristics towards various LiPS compared to InN?

Answer: the built-in electric field will form electronic-rich and electronic-deficient sites in heterojunction, which can improve the adsorption capability of LiPSs. In AlN side, there are more electronic-rich sites that is favorable for the adsorption of Li+.

3. How did the authors conclude rate determining step based on adsorption? The rate-determining step can vary based on various reaction parameters. Authors need to be specific and discuss more on this.

Answer: For calculated system, the Gabbs gree energy is roughly equal to the adsorption energy. The calculation fomula of the reaction Gibbs free energy has been added in manuscript.

4. How would be catalytic activity of heterojunction compared to the individual nitrides? what materials properties changes can be expected to drive effective LiPS catalytic transformation mechanisms. Need more details on that. 

 Answer: The catalytic activity of heterojunction has been widely discussed through experiments and theoretical calculations, for example J.Mater.Chem. A 10, 939-949 (2022), Small 19, 2206462 (2023), Small, 2309422 (2024) et al.. We want to clarify which polysulfide is transferring from one side of the heterojunction to another side. Comparing free energy profiles individual nitrides AlN and InN (as shown in inset Fig.4), it can be obtained that the reduction process from S₈ to Li₂S₆ is thermodynamically more favorable on AlN surface than InN and it is more favorable for InN during the reduction from Li₂S₄ to Li₂S₂. So Li2S4 is transfered from one side of the heterojunction to another side. This confirms the synergistic effect of AlN and InN. AlN traps large Li₂S₈ and Li₂S₆, junction forms diffusion of Li₂S₄ and InN completes the conversion of Li₂S₄ to Li₂S, which realize the synergistic reaction of trapping-diffusion-conversion for LiPSs in the surface and interface of catalytic agent.

 

5. Overall, need to discuss more in technical detail about the results. 

Answer: More migration details can theoretically be achieved through molecular dynamics simulations, but the Li2S4 molecule is too large to realize at present, and then we need to continue our efforts.

Author Response File: Author Response.pdf