Novel Composite Electrode of the Reduced Graphene Oxide Nanosheets with Gold Nanoparticles Modified by Glucose Oxidase for Electrochemical Reactions
, Yang Liu 1, Qinsi Shao 1, Aijun Li 1, Wei Yan 1,* and Jiujun Zhang 1,*Round 1
Reviewer 1 Report
catalysts-584746
Novel Composite Electrode of the Reduced Graphene 3 Oxide Nanosheets with Gold Nanoparticles Modified 4 by Glucose Oxidase for Electrochemical Reactions
Reviewer 1
The manuscript presents synthesize of a novel composite material of the reduced graphene oxide nanosheets with gold nanoparticles, the characterization of its morphology, structure and composition and its catalytic activity toward glucose oxidation and oxygen reduction reaction. Some aspects should be clarified before its publication.
3.2. Potentiostatic reduction of GON-AuNP.
Page 9
Line 243: Please explain why the authors have chosen a longer time then 200 seconds for the potentiostatic reduction of GON-AuNP since after 200 seconds the behaviour og he material was similar?
3.3. Direct electron transfer between GOD and rGON-AuNP/GC electrode
Page 11
Peaks description in Fig. 4 a and B are confused.
Line 283. Authors state that the potential of peak IV can be obtained from the voltammogram, but the peak potential of peak III cannot be obtained. Please check.
Line 286: Please specify which the first pair of redox peaks is.
Page 13.
Fig. 4. Please indicate by arrows on the voltammograms the sense of potential variation.
Fig. 4B. There is not any explanation about this voltammogram.
Page 14
Line 331. Please make a comment about obtained values of charge transfer coefficient and compared with theoretical ones.
3.5. Electrocatalytic behavior of GOD/rGON-AuNP/GC electrode toward glucose oxidation
Page 17
Fig. 7A. Please correlate curves b-m with their colors
Fig. 7B. Please specify the potential used.
Author Response
Please see the attachment.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Graphene-based materials are highly promising for electrochemical applications. However, they suffer from various challenges such as irreversible self-agglomerations, less colloidal stability, poor reliability, and non-specificity. In this work, a facile way to in-situ synthesize a composite of graphene oxide with AuNP is reported, resulting in uniformly dispersed AuNP tightly anchored on GON. Overall, the authors proposed a novel composite electrode with good electrochemical properties for catalytic activity. I think this paper provides good insight toward enabling facile graphene-based material fabrication and its relevant application. I suggest this work to be published after a minor revision.
For figure 2C, various regions associated with different weight loss mechanisms should be labeled in the plot for better visualization.
For figure 2d, G and D peaks should be labeled in the plot.
On page 9, what does it mean by “After 200 seconds of reduction, the reduction peak cannot be observed any more on the cyclic voltammograms”? It seems like no reduction peak can be observed starting at 0 second. More explanation is needed.
For figure 3a, reduction & oxidation peaks should be labeled.
For figure 3b, an equivalent circuit diagram should be provided.
The authors should provide summary table that compares this work vs. the previous reports in terms of synthesis pathway, structural properties, electrochemical behaviors and catalytic activity.
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Reviewer 3 Report
Manuscript can be published in present form.
Author Response
We thank the reviewer for his/her careful evaluation and the kind recommendation.
Author Response File: Author Response.pdf
Reviewer 4 Report
Authors reported gold nanoparticles deposited on reduced graphene oxide nanosheets for electrocatalyst materials. Their electrochemical performance on glucose oxidation was evaluated and explained well. Their characterization data are also good enough. Comments and questions are only for IR analysis as the following.
1. It is strongly recommend to add the size distribution and average size of Au nanoparticles from TEM images, even though authors simply mentioned that the diameter range from 6 to 10 nm on page 4.
2. In Figure 2(A), a thinner line thickness would be better for checking peak position and shape exactly, e.g. (NH2) and (CH2) stretching peaks.
3. The assignments of C-H stretching peaks are opposite on Page 5, line 2841 would be symmetric, while 2934 should be asymmetric.
4. What is the reason for weak (NH2) stretching peak at around 3400 cm-1 in spite of strong N-H bending and deformation peaks in Figure 2(A).
5. Isn't there any shift with IR peaks related to NH2 groups after Au NP adsorption on the amino groups of APTS?
6. The (NH) deformation peaks of GON-AuNP are measured at 1651 cm-1 in Figure 2A and 1625 cm-1 in Figure S1A. Why are they different?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
