Electrochemical Degradation of Crystal Violet Using Ti/Pt/SnO2 Electrode
, Mhamed Abali 2, Lahcen Bazzi 1, Mustapha Hilali 1, Souad El Issami 1, Karine Groenen-Serrano 3,* and Hanane Zejli 1,*
Round 1
Reviewer 1 Report
Authors have studied the electrochemical degradation of crystal violet using commercial Ti/Pt/SnO2 electrode, some major issues need to be addressed as follows:
- The title should be changed to : Electrochemical degradation of crystal violet using Ti/Pt/SnO2 electrode
- The innovation of this work has not been highlighted
- What are the authors based on to choose the operational conditions, have screening experiments been carried out?
- During the study of the pH effect on the degradation of CV, the solution was not buffered, the pH values may vary with the degradation time taking into account the production of new intermediates and the oxidation reaction of water. Have the pH values been measured during the reaction time?
- Page 2, Lies 74-78 : Can Authors support that statement with references?
- Figure 6.a needs to be referenced
- Authors can estimate the Instantaneous Current Efficiency (ICE) from the COD data measured (10.1016/j.electacta.2016.05.015). Evaluation of such parameter will definitely enrich the discussion.
- Authors talked about mineralization, what is the TOC removal in the system?
- Did authors observe any degradation (leaching) of the electrode when used as anode? You can use ICP for this. (Note that Ti, P and Sn are bioaccumulative and chronic exposure risk should then be also discussed)
- Compare the obtained results of the degradation with relevant literatures using the same electrodes
- Equation 5 should be removed to Materials and methods section
- The formula of the kinetics must be referenced.
- Experimental works should be done in replicates. If so, error bars should be added in all figures
- In all curves including those ones in SI, change comma (,) to point (.)
- Too English mistakes remain in the text, please revise
Author Response
Please see the attachment.
Author Response File: 
Author Response.docx
Reviewer 2 Report
The paper discusses electrochemical degradation, however, the results section lacks comparison to literature. R&D section needs comparison to electrochemical processes, there are many publications on this process using different chemicals.
Author Response
We have considered very carefully these remarks. Numerous studies are present in the bibliography devoted on the use of lead dioxide and (more recently) boron doped diamond electrode. However, these electrodes have disadvantages such as heavy metal contamination and high cost, respectively. A big part of the introduction has been corrected. To complete this study an entire paragraph has been added devoted on the comparison of the results obtained in this work and representative results of the bibliography (see lines 423-447).
Round 2
Reviewer 1 Report
-Barr errors are missing in Figures 7, 8 and 9
-Table 3 is unuseful in its form, no conclusions can be made as many electrodes have been cited, authors should keep the same material as theirs
Author Response
-Barr errors are missing in Figures 7, 8 and 9 :
As requested by Reviewer 1, figures 7 to 9 have been improved by adding error bars
-Table 3 is unuseful in its form, no conclusions can be made as many electrodes have been cited, authors should keep the same material as theirs.
We do not understand this remark because one of the objectives of this study is to show that among the high oxygen overvoltage anodes, the SnO2 electrode represents a material of choice. For this reason:
-we discussed in the introduction the advantages and disadvantages of the main studied anode materials.
-At the end of the study, we compared the performance of this electrode in terms of energy consumption with the other materials in different operating conditions. Therefore, it is useful to present the table with results obtained with different anode materials.
Reviewer 2 Report
Some Figures still need error bars.
Author Response
Comments: Some Figures still need error bars.
As requested by Reviewer 2, figures 7 to 9 have been improved by adding error bars
