In Situ Surface Reconstruction of Catalysts for Enhanced Hydrogen Evolution

Round 1

Reviewer 1 Report

This review summarizes the recent advances on various types of structure deriving from in-situ reconstruction and self-optimization of active sites in HER process. Finally, the perspective and outlooks are offered to guide future investigations. This review is expected to provide some new clues for a deeper understanding of in situ surface reconfiguration in hydrogen evolution reaction and for the targeted design of catalysts with desirable structures. This paper could be accepted after minor revision.
（1）In Abstract, “This review summarizes the recent advances on various types of structure deriving from in-situ reconstruction and self-optimization of active sites in HER process”, various types of structure should be listed here.
（2）Several methods of in situ characterization such as XAFS, STEM, XRD, Raman, etc. should be introduced in the Introduction part.
（3）“Synergistic effects” as one part of this paper should be discussed in detail.
（4）“Big data and artificial intelligence technologies are both hot fields nowadays, and they have gained widespread attention and rapid development for their time-saving and efficient nature” in the part of Conclusions and future prospects. What the Big data and artificial intelligence technologies?

Author Response

1. In Abstract, “This review summarizes the recent advances on various types of structure deriving from in-situ reconstruction and self-optimization of active sites in HER process”, various types of structure should be listed here.

Reply: Various types of structure such as reconfiguration of crystallinity, morphological evolution, chemical composition evolution, phase transition refactoring, surface defects, interface refactoring have been added and been listed there.

2. Several methods of in situ characterization such as XAFS, STEM, XRD, Raman, etc. should be introduced in the Introduction part.

Reply: Several methods of in situ characterization such as XAFS, STEM, XRD, XPS, Raman, etc. have been introduced in the Introduction part.

3. “Synergistic effects” as one part of this paper should be discussed in detail.

Reply: “Synergistic effects” as one part of this paper have been discussed in detail.

4. “Big data and artificial intelligence technologies are both hot fields nowadays, and they have gained widespread attention and rapid development for their time-saving and efficient nature” in the part of Conclusions and future prospects. What the Big data and artificial intelligence technologies?

Reply: AI is capable to develop efficient data analysis software owing to its penetration in the processing of computer vision, language processing, image recognition and so on. As one of the most powerful strategies within AI, machine learning is to use machines to learn from previous experience, detect patterns, and make fast and accurate

predictions. Machine learning has been successfully applied to catalyst design and exhibits an amazing precision in comparison with DFT calculation results.

Reviewer 2 Report

Comments to the Authors:

This review summarized the in-situ surface reconstructions of catalysts during HER progress in detail. It provides a good list of references and hints for feasible future research direction on developing high-efficiency electrocatalysts for hydrogen evolution, so I recommend its acceptance in Catalysts after a minor revision.

Detailed suggestions are listed as follows:

1. A timeline of essential steps in developing in-situ surface reconstruction approaches is suggested to be supplemented.

2. Authors could consider listing tables to compare catalytic performances of electrocatalysts modulated via in-situ surface reconstruction.

 

3. Some apparent errors exist. For example, the statements on Figure 2F are missing in the main manuscript. In line 174, “As shown in Fig. 5G” could be “As shown in Fig. 3G”.

Author Response

Reviewer 2

This review summarized the in-situ surface reconstructions of catalysts during HER progress in detail. It provides a good list of references and hints for feasible future research direction on developing high-efficiency electrocatalysts for hydrogen evolution, so I recommend its acceptance in Catalysts after a minor revision.

Detailed suggestions are listed as follows:

1. A timeline of essential steps in developing in-situ surface reconstruction approaches is suggested to be supplemented.

Reply: A timeline of essential steps in developing in-situ surface reconstruction approaches have been supplied.

2. Authors could consider listing tables to compare catalytic performances of electrocatalysts modulated via in-situ surface reconstruction.

Reply: The tables to compare catalytic performances of electrocatalysts modulated via in-situ surface reconstruction have been given.

Catalyst	Reconstruction Types			Electrolyte	Performance
H-NiFe LDH[18]	Reconfiguration of crystallinity			1.0    M KOH		Tafel slope of 62.30 mV dec-1
H-TaS2[30]	Morphological evolution			0.5 M H2SO4		Tafel slope of 37 mV dec-1
Fe@FeOxSy [19]	Complete species transition			1 M KOH		Tafel slope of 77 mV dec-1
HxZIS [36]	In situ surface hydrogenation			0.35 M/0.25 M Na2S-Na2SO3		90μmol H2 amount at each hour of HER
S-O-MoS2 [37]	In situ surface oxygen doping			with O doping (20.0 mg) and 20 mg EY dye in 100 mL of TEOA solution (15%, v/v) aqueous solution at pH 7.		The maximum rate of H2 production reached 1.6 mmol h−1 g−1.
TiO2@MoS2 [20]	Phase transition refactoring			80 mL of 15% (v/v) TEOA aqueous solution under visible light irradiation (l > 420 nm). Catalysts: 20 mg and EY: 20 mg.		The maximum rate of H2 production reached 10.5 mmol h−1 g−1.
1T-WS2 [43]	Phase transition refactoring			0.5 M H2SO4		Tafel slope of 40 mV dec-1
Multilayer MoS2 [55]	Surface defects			0.5 M H2SO4		Tafel slope of 102 mV dec-1
Monolayer MoS2 [55]			Surface defects	0.5 M H2SO4		TOF=1.0 s-1 at -100 mV
Co(OH)2@MXene [60]		Interface refactoring		1 M KOH		a low overpotential of 28 mV at 10 mA cm-2

Reviewer 3 Report

This review summarizes the in situ reconstruction of catalysts during HER reactions including the reconfiguration of crystallinity, morphology evolution, chemical composition evolution, phase transition and surface defects introduced, and how they affect the catalytic performance respectively. This review provides some perspectives that are expected to be meaningful for future catalyst design and development. This review could be accepted after minor revision.

(1)     This paper is mainly about hydrogen evolution reaction, so the keywords need to be adjusted to take “hydrogen evolution reaction” as the key words.

(2) The structural reconstruction involves photocatalytic hydrogen production and electrocatalytic hydrogen production, which need to be specifically described in this paper.

(3) Not all structural refactoring results in self-optimizing performance, and even most refactoring results in performance degradation, as noted in this article.

(4) As we all know, there are a lot of literatures on structural reconstruction, and the references in this review are obviously too few. Please supply the references as much as possible to enrich this review

Author Response

Reviewer 3

This review summarizes the in situ reconstruction of catalysts during HER reactions including the reconfiguration of crystallinity, morphology evolution, chemical composition evolution, phase transition and surface defects introduced, and how they affect the catalytic performance respectively. This review provides some perspectives that are expected to be meaningful for future catalyst design and development. This review could be accepted after minor revision.

(1) This paper is mainly about hydrogen evolution reaction, so the keywords need to be adjusted to take “hydrogen evolution reaction” as the key words.

Reply: The “hydrogen evolution reaction” has been taken as the keywords.

(2) The structural reconstruction involves photocatalytic hydrogen production and electrocatalytic hydrogen production, which need to be specifically described in this paper.

Reply: The structural reconstruction involves photocatalytic hydrogen production and electrocatalytic hydrogen production have been specifically described in this paper.

(3) Not all structural refactoring results in self-optimizing performance, and even most refactoring results in performance degradation, as noted in this article.

Reply: As the Reviewer said Not all structural refactoring results in self-optimizing performance, and even most refactoring results in performance degradation. However, we focus on the “In situ surface reconstruction of catalysts for enhanced hydrogen evolution”

(4) As we all know, there are a lot of literatures on structural reconstruction, and the references in this review are obviously too few. Please supply the references as much as possible to enrich this review

Reply: Much more references have been added to enrich this review.

Reviewer 4 Report

This review gives a good summary of in-situ surface reconstruction of catalysts of HER and classifies these into 6 types. It would help researchers better understand the in-situ surface reconstruction and further develop new catalyst.  However, there are several aspects of this study that should be improved： 

1. In the abstract, the author claims that "more and more in situ and/or operando techniques has been explored to track the dynamic structural evolution of HER catalysts for clarify......", but this section is lacking in the main text. There's only one sentence described in the conclusion (line #573-575). It would be better if these techniques are documented in a separated section. 

  

2."the reaction intermediates" and "mechanism" were referred many times throughout the whole paper, but what they are? Can author give a short summary of the reaction mechanism of HER? It will help readers a lot. 

  

3.There are two types of HER this review mentioned, including the photocatalytic HER and electrocatalytic HER. It should be stated clear in the abstract as well as in each case this review refers. Also, if the author really wants to include these two types of HER together, both cases referring to photocatalysis and electrocatalysis should be given in each type of reconstruction at lease. Besides, the reaction media (acid, neutral, or base) of HER should also state clearly from case to case. 

  

4. The author should give the full name of abbreviations in this review. Most of them are missing. 

  

5. The review gives a excellent description of "phase transition refactoring" in line #342-345. However, the definitions to the rest five types of in-situ reconstructions are missing. Should make definitions to them as well.  

  

6. Others: 

>> Some sentences are really confusing, ie.  

--Line #208-212 "And about the formation". This sentence needs to be revised. 

--Line #573-575 "At present, the dynamic evolution of HER..." Why were the CO2RR, NRR and OER mentioned here? 

  

>>  Some figures need to be reconstructed, ie. 

--Figure 3A and 3B, the scale bars are missing 

--Line #174, Fig.5 (5G indeed) was first mentioned in this paper, it should be included into Fig.3 or Fig.4, rather than being placed far behind. Should reconstruct these figures. 

  

>> Based on Fig.1, 6 types of in-situ constructions were summarized, but why did the author claim five types of them in Line #78 and Line #559? Need to double-check. 

  

>> Line #133: what does the "hydrogen precipitation reactions" mean? Is there any difference between HER and "hydrogen precipitation reactions"? Same to the Line #174. 

  

Hope the author make the necessary work to improve the review manuscript quality. 

Thanks. 

  

 

Author Response

This review gives a good summary of in-situ surface reconstruction of catalysts of HER and classifies these into 6 types. It would help researchers better understand the in-situ surface reconstruction and further develop new catalyst.  However, there are several aspects of this study that should be improved：

1. In the abstract, the author claims that "more and more in situ and/or operando techniques has been explored to track the dynamic structural evolution of HER catalysts for clarify......", but this section is lacking in the main text. There's only one sentence described in the conclusion (line #573-575). It would be better if these techniques are documented in a separated section.

Reply: In situ and/or operando techniques has been added as a separated section in the manuscript.

Figure R1 in situ and/or operando techniques for in situ surface reconstruction of catalysts.

2."the reaction intermediates" and "mechanism" were referred many times throughout the whole paper, but what they are? Can author give a short summary of the reaction mechanism of HER? It will help readers a lot.

Reply: A short summary of the reaction mechanism of HER has been given in the manuscript.

 

Figure R2 The reaction mechanism of HER

3.There are two types of HER this review mentioned, including the photocatalytic HER and electrocatalytic HER. It should be stated clear in the abstract as well as in each case this review refers. Also, if the author really wants to include these two types of HER together, both cases referring to photocatalysis and electrocatalysis should be given in each type of reconstruction at lease. Besides, the reaction media (acid, neutral, or base) of HER should also state clearly from case to case.

Reply: The photocatalytic HER and electrocatalytic HER have been stated clear in the whole manuscript. The reaction media (acid, neutral, or base) of HER also have been stated clearly from case to case.

4. The author should give the full name of abbreviations in this review. Most of them are missing.

Reply: All the full name of abbreviations in this review have been given.

5. The review gives a excellent description of "phase transition refactoring" in line #342-345. However, the definitions to the rest five types of in-situ reconstructions are missing. Should make definitions to them as well.

Reply: The definitions to the rest five types of in-situ reconstructions have been added.

 

6. Others:

>> Some sentences are really confusing, ie. 

--Line #208-212 "And about the formation". This sentence needs to be revised.

--Line #573-575 "At present, the dynamic evolution of HER..." Why were the CO₂RR, NRR and OER mentioned here?

Reply: This sentence has been revised. “It has been reported that the formed iron nanoparticles could be rapidly partially oxidized in aerobic environment and a thin crust of ferric oxide around the nanoparticles appeared”.

  The CO₂RR, NRR and OER were mentioned here to illustrate that refactoring can also occur beyond the HER and also should be paid more attention.

>> Some figures need to be reconstructed, ie.

--Figure 3A and 3B, the scale bars are missing

--Line #174, Fig.5 (5G indeed) was first mentioned in this paper, it should be included into Fig.3 or Fig.4, rather than being placed far behind. Should reconstruct these figures.

Reply: The scale bars of Figure 3A and 3B have been added. The Fig.5G has been changed into Fig.3G

>> Based on Fig.1, 6 types of in-situ constructions were summarized, but why did the author claim five types of them in Line #78 and Line #559? Need to double-check.

Reply: “five types” has been changed into “six types”.

>> Line #133: what does the "hydrogen precipitation reactions" mean? Is there any difference between HER and "hydrogen precipitation reactions"? Same to the Line #174.

Reply: "hydrogen precipitation reactions" have been changed into "hydrogen evolution reactions"