Structural Evolution of Ni-Based Co-Catalysts on [Ca2Nb3O10]− Nanosheets during Heating and Their Photocatalytic Properties
Round 1
Reviewer 1 Report
The paper provides a description of thorough investigation concerning the structure and catalytic properties of Ni-based cocatalysts on [Ca2Nb3O10]- nanosheets. The conclusions are quite interesting and the explanation and ideas presented in the paper may be helpful for understanding the design and preparation of more efficient catalytic materials. This quite important paper is probably publishable, however, there is a number of issues to be addressed:
The title: 'structure and photocatalysis' - as I understand, photocatalysis is a phenomenon, not a feature. I suggest to change the title to include 'photocatalytic properties of ...'. In the introduction (line 44): 'structures can be synthesized on nanosheets [13,14], nanotubes [8,15,16], and nanoparticles [17-20].' More details are needed. Please describe in more detail. In the introduction (lines 57-68): please separate the known information more clearly from the new intentions, inventions and discoveries presented in the paper. Results and Discussion (line 77): '100 wt% Ni loading' - not clear. Do the author mean metallic nickel bars? The same situation in some further places within the text wherever we deal with Ni concetration. Was the chemical composition of the samples tested? Do the labels only specify the authors' intentions as to the composition of the samples tested? Results and Discussion (line 113): While describing XDR results we should use 'diffraction line' expression or 'reflex' instead of 'diffraction peak' (diffraction is not spectroscopy). Materials and Methods (line 267): 'Fourier transform infrared spectroscopy (FTIR) was measured' with what? This method was used to obtain some results, but it was not measured itself. Conclusions: could the authors describe the technological and application aspects of their research more broadly in the entire work, and in particular in their conclusions?Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Authors reported Ni co-catalyst for HER reaction with systematic investigation from its loading onto [Ca2Nb3O10]- to Ni@NiO core-shell nanoparticles formation. Especially it is quite interesting to observe Ostwald ripening during in-situ heating as well as the structural evolution of Ni. Comments are the following.
1. Figure 1(c)
It is strongly recommended to include the IR spectra of [Ca2Nb3O10]- nano sheets with 25 and 0 wt% NI loading. In addition, other IR peak assignments are also required for the region between 1200 and 1800 cm-1.
2. Page 8, line 224
Effect may be better than "Mechanism".
3. It is strongly recommended to try another photocatalytic reaction or recycle test for better application or potential evaluation.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
