Comparative Study between NiCoB and IrO₂-Ta₂O₅/Ti Anodes for Application in Impressed Current Cathodic Protection (ICCP)

Round 1

Reviewer 1 Report

This manuscript studied the comparative corrosion properties on impressed cathodic current protection system of the NiCoB and IrO₂-Ta₂O₅/TiO₂ coatings on carbon steel. The authors concluded that the corrosion protection performance of the NiCoB/CS coating is comparable to the IrO₂-Ta₂O₅/Ti coated anodes, indicating that the NiCoB/CS anode materials are promising for the low-cost candidates in ICCP systems. Although the scientific content of the manuscript is well-suited for publication in Coatings, the quality of the present form of the manuscript is not good enough to be considered for the publications. I believe that the manuscript must be revised thoroughly on the following points for the further consideration.

1.There are many syntax, grammatical and spelling errors. English of the manuscript should be thoroughly revised by the native professionals

2. Line 62 stated that “… oxygen and chlorine evolution in NaCl and H₂SO₄”: Ca(OH)₂ or H₂SO₄? How could the authors study the chlorine evolution in H₂SO₄ solution? Manufacturer and product name of the coating samples should be added in the manuscript.

3.In Line 89, the “work electrode” should be corrected to the “working electrode”.

4.A clear scale bar should be added to SEM images of Fig. 1 and Fig. 3. Deconvolution of the XRD peaks are required to justify the existences of all those phases shown in the inset (a) and (b) of Fig. 2.

5.Table 2 should be revised. Instead of “Vcorr” , it should be “coatings’ samples” This Table should be presented similar to that of the Table 3.

6.The unit of Vcorr in Table 2 should be corrected. The font size of Fig. 4, 5 and 6 should be enlarged. In conclusion, the corrosion rate with deviation ((0.02 ± 0.01 mm/year) is stated.

7.The authors should discuss about this deviation in the result and discussion section. How many samples were tested to estimate this deviation? However, the deviation looks too large.

8.In the conclusion part, it is stated that the gas evolution reaction mechanisms of the two materials were different. The mechanism should be discussed in detail in the results and discussion part.

9.The subscript in the following compounds should be corrected in the References: IrO2, Ta2O5, RuO2, TiO2.

Author Response

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Reviewer 2 Report

The present manuscript reports the analysis of a cathodic protection system to be applied for impressed current cathodic protection. The authors compared carbon steel coated with nickel/cobalt/boron with commercial titanium anodes coated with iridium and tantalum oxide. Results showed that the performance of both materials is almost comparable.

I do not recommend the publication in Coatings Journal, except that after a careful revision of the following points:

Major revision:

1.Recommend a careful revision of English.

2.The Materials and Methods section is very poor of description. How are the corrosion rate, and the electrochemical characterization evaluated? In the second case, section 2.2 comprehends the description of the analysis of the overpotential as well as the exchange of current and values of the Tafel slope?

3.Please the authors refine this section to let the reader understand the methods used. All values completely missing a standard deviation (for example Table 2 and Table 4), or other parameters that can describe the collected data.

4.Is the high difference in thickness (52 um for NiCoB and 630-1000 um for IrO2TaO5) extremely influent on the results reported in the manuscript? The difference is more than one order of magnitude.

5.Please the authors discuss more regarding the choice of materials. The real novelty of this study is not so clear. Which could be the real advantage of using NiCoB? Is it cheaper, or more processable than other coatings? Please the authors amplify these aspects.

Minor revision:

6.Page 1: which is the meaning of GDP in line 38.

7.Page 2: is not clear the meaning of the equations (1) and (2) in the discussion. Please the authors clarify it. Please the authors clarify the meaning of line 17 “Vladimir and Branislav Z. (2007) [17]”. Please the authors better clarify the dimensions of the materials used, and their origin (suppliers).

8.Page 3: which are the references connected to the “previous studies” in line 105? Figure 1 misses the scale bar.

9.Table 2 reports “ano” instead of year.

10.It is not completely clear the comparison between Figure 3a and Figure 3b. It seems there is a huge difference in the scale bar between the images.

11.Please report more details on the claimed presence of pores. It is not clear how the corrosion rate was estimated. How many cycles were tested during the cyclic voltammetry test?

12.It is difficult to assess how the results reported in Table 5 are statistically different. Please the authors add standard deviations. The same for Table 6.

Author Response

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Round 2

Reviewer 1 Report

The revision has improved the quality of the manuscript. However, there are still some issues, which have not been addressed properly. I suggest the authors to revise the manuscript properly on the following points.

• Based on the XRD analysis, 72% of Co, 10.85% of Co₂B and 16.92% of Ni have been reported in the NiCoB/Cs coating. However, the % composition of the various phases is not 100%.

• In Fig. 2, the standard XRD patterns of all the phases from their respective JCPDS files should be added, and the corresponding JCPDS file numbers should be noted in the relevant text of the manuscript.

• English of the manuscript needs to be improved.

Author Response

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Reviewer 2 Report

Please the authors uniform the notation in the Tables as scientific or not scientific.

I do not have any further comments.

Author Response

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