Methods to Generate Structurally Hierarchical Architectures in Nanoporous Coinage Metals

Round 1

Reviewer 1 Report

The authors describes preparation of nano-porous metal structures and their modern application potential.

The review is well structured and comprehensive.

I recommend publishing in current form.

 

Author Response

We are pleased that the reviewer found our review useful.

Reviewer 2 Report

The submitted manuscript which is classified as review briefly summarized methods commonly used for preparation of porous nanostructures of metals. Gold is discussed as the most interesting metal of this review other metals are discussed rarely except for silver. Therefore, the title can be changed to “Methods to generate structurally hierarchical architectures in nanoporous coin metals”. The review is bringing a basic information from the field of the preparation of these structures and can be useable for scientists starting in this field even if the presented information is not the latest at some parts of the text. Maybe, the review can be more interesting if more applications of the discussed structures will be presented in the text. However, I can recommend this manuscript for publication in the Coatings journal.

Author Response

The title has been changed to “Methods to generate structurally hierarchical architectures in nanoporous coinage metals”. 

Applications of the discussed structures are now mentioned in the text. The general applications are listed in the Table.

Ref 24: The catalyst prepared in this way has shown advanced performance towards one-pot transfer hydrogenation reactions of diverse nitroarenes to anilines

Ref 26: The resulting architecture is comprised of micrometer-sized ligament channels and small ligament pores in the nanometer range. The catalytic activity for methanol electro-oxidation in alkaline solution using such materials has shown their remarkable performance in the field of catalysis and sensing.

Ref 33: This is a green, convenient, and economical method used to build 3D micro/nanostructured PGFs which exhibited high electrocatalytic activity towards the oxidation of ethanol, glucose, and ascorbic acid

Ref 34: Primary results have shown that the hierarchical structure generated has excellent catalytic activity toward methanol oxidation which is due to the special structure of the electrode providing more active sites for the adsorption of OH^- anions

Ref 35: The hierarchical design of the electrode has been exploited for the detection of glucose in human blood samples with a detection limit of 0.1 μM owing to the facile electron conductivity due to the large active surface area

Ref 38: The open and porous structure facilitates the mass transport and charge transfer which may hold great potential for its use in electrode material for electrocatalytic reduction of peroxide and other electrochemical reactions

Ref 40: The new double-templated electrodeposition approach is very attractive as the final material holds considerable promise for designing electrocatalytic surfaces for enhanced oxygen reduction reaction and hydrogen-peroxide detection

Ref 41: It is envisioned that the structure generated using this approach will be useful as platforms for chemical sensing, chromatography, and catalysis

Ref 43: It was seen that the selective wetting behavior of Au affected the growth kinetics on the substrate giving rise to a hierarchical material that is of great interest for applications in organic photovoltaics and electronics

Ref 47: The ordered architecture of the material with pore dimensions comparable to optical wavelength could display unique optical properties

Ref 50: It is believed that the use of bijels for creating hierarchically porous metal electrodes can offer enhanced performance for their use in supercapacitors, rechargeable batteries, and catalysis

Ref 56: This technique successfully printed hierarchical metallic aerogels, enabling control over the density, electrical, and mechanical properties of the aerogel. These superior properties have paved their way in the fields of aerospace, biomedicine, defense, and smart structures

Ref 57: The structural design is found to be useful for different energy applications, such as batteries and fuel cells

Ref 58: The hierarchical NPG dot arrays generated via this methodology are effective for SERS and metal-enhanced fluorescence (MEF) techniques for highly sensitive molecular sensing

Reviewer 3 Report

This review reports on the methods to generate structurally hierarchical architectures in nanoporous metals. The authors extensively discussed various approaches to prepare nanoporous gold and other metals. They focus the attention on the techniques of preparation, while no significant examples are reported on the application of these different materials. For example the authors could consider to mention a general discussion on nanoporous metals preparation and multiple use in spectroscopy and photocatalysis as reported in ACS Nano 2021, 15, 4, 6038–6060

To me the paper is well written, and it sounds like an interesting review. I can recommend the publication

 

Author Response

A general discussion on nanoporous metals preparation and multiple use in spectroscopy and photocatalysis as reported in ACS Nano 2021, 15, 4, 6038–6060 has been added (L93)

Hierarchical materials particularly traditional coinage metals have large porosity channels with several smaller pores on channel walls which enhances the density of plasmonic hotspots making it a suitable platform for surface-enhanced Raman spectroscopy (SERS) for ultrasensitive sensing applications as well as photocatalysis

Reviewer 4 Report

This paper is a review of the creation of structurally hierarchical architectures and is very well written, covering past research, current research, and future perspectives. I recommend the publication of this paper in Coatings.
However, I felt uncomfortable when the combination of artificial intelligence and 3D printing suddenly appeared in the future prospects section (L432). Authors should write this sentence after mentioning, with references, what advantages there are in combining artificial intelligence and 3D printing (e.g., accelerating structure search, suggesting structures that humans cannot come up with). Although reference 10 mentions the potential of artificial intelligence for 3D printing in the last perspective section, the reference itself does not treat a combination of artificial intelligence and 3D printing.

Author Response

The advantages of combining artificial intelligence and 3D printing (e.g., accelerating structure search, suggesting structures that humans cannot come up with) have been added in the text:

The development of 3D printing technology in medicine is proceeding very rapidly. Additionally, in the era of the digital world, artificial intelligence is emerging as a game-changer in healthcare systems. To gain benefits in the mainstream clinical practice, 3D printing harnessing modern technology of AI could potentially increase the performance by reducing the risk of error, ensuring stringent quality control, reducing material wastage, and giving the benefit of automated production [66,67]. Recently, AI has been utilized in designing novel materials with complex architectures and unique material properties such as elasticity, plasticity, and wear performance. The key issues lie in the selection of proper methodology and the positioning of the functional elements in the resulting 3D structure. However, with the integration of AI and material design, the study of bioinspired hierarchical materials has been done by casting the natural process of evolution into a computational framework and thereby accelerating the material property prediction process [10,68]. In the near future, it will be interesting to link the field of artificial intelligence with 3D printing technology to discover new microstructural patterns leading to advanced materials in a vast design space.