Preparation and Electrochemical Properties of Co3O4 Supercapacitor Electrode Materials
Round 1
Reviewer 1 Report
The submitted work titled ‘Preparation and Electrochemical Properties of CO3O4 Supercapacitor Electrode Materials’ reported that simple synthesis method which gas-phase diffusion precipitation method to produce Co3O4 electrode materials for supercapacitor. Also, additional modification process improved its electrochemical properties. However, in my view, novelty and data description of this manuscript are premature. although the concept may potentially be interesting it clearly needs more in-depth and detailed studies before considering publication. In the present state I cannot recommend publication in Crystals.
Q1) To reinforce this manuscript, I would recommend the authors to enhance the novelty descriptions of this work in introduction part compared to other preparation methods.
Q2) I would recommend to describe detailed electrochemical performance experiments in Materials and Methods section.
Q3) How much of these three each of electrode loading mass?
Q4) The authors claim that the morphology of electrode A is “nano-spherical morphology”. However, considering its size, it should be described micro-spherical morphology.
Q5) The author claim that some small nanoparticles exist in the middle of petals on electrode C and it is due to the phosphate modification. Please the authors address that how the phosphate effects to create nanoparticles.
Q6) Similarly, authors claim that the discharge time of electrode C was increased after modification process, please explain how the discharge time of electrode C was increased?
Q7) In the results and discussion section, the authors use “capacity”. It should be corrected to “capacitance”
Q8) Although the electrode C exhibit the maximum capacitance compares than the others, the deterioration of capacitance is significant at high current density. Please explain this results.
Q9) Figure 6 shows CV curves of three electrodes, it is clear to see that the redox peak on electrode C was changed compare to the others. Please address why the redox peak was changed.
Q10) To clarity, I would recommend to use the unit represents to ‘Potential (V vs reference electrode; which the author used or converted to RHE)’ and ‘Current to Current density (geometric current density)’.
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
This paper presents the Co3O4 supercapacitor electrodes with different morphologies. I suggest publication after adressing the comments below
- A B C should be explained in section 2 and the table
- the modification should be explained
- the changes of morphology should be explained and previous reports should be cited.
- table with previous results for Co3O4 electrodes should be given
- discussion part should be improved
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Reviewer 3 Report
Different Co3O4 supercapacitor materials were prepared by a special gas phase diffusion precipitation method. Some physical and electrochemical characterization methods have used to establish influence of synthesized materials properties. The manuscript is logically built up, the topic is interesting, however its content needs some improvement.
Introduction section: Some other low cost transition oxides have extensively been used for supercapacitor applications can be referred as well, such as (DOIs: 10.3390/nano8070487 and 10.1149/2.1161613jes).
Characterization of Figure 7 is insufficient. Authors should be use the suitable equivalent scheme for fitting experimental results.
Author Response
Please see the attachment.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The revised manuscript is much improved. it seems suitable to be accepted in Crystals after tiny minor corrections are made:
the line 152 in results and discussion, the size of font is different. Please check the size of font. Also, the line 215 in results and discussion section, I thought the authors mistyped the order of samples. Please correct this to “the charge transfer resistance (Rct) of B synthesized by CoCl2·6H2O is smaller than the A synthesized by Co(OAc)2·4H2O.”
Author Response
We deeply appreciate your constructive comments.
The size of font on the line 152 in results and discussion has been corrected.
On the line 215 in results and discussion section, the order of samples has been aslo corrected. It has been corrected to “the charge transfer resistance (Rct) of B synthesized by CoCl2·6H2O is smaller than the A synthesized by Co(OAc)2·4H2O.”
Finally, we would like to thanks the reviewer for your help and constructive suggestions.
Reviewer 3 Report
Accept in present form.
Author Response
We deeply appreciate your constructive comments that greatly help improve the technical quality and the presentation of this manuscript.
