Integrated p-n Junctions for Efficient Solar Water Splitting upon TiO2/CdS/BiSbS3 Ternary Hybrids for Improved Hydrogen Evolution and Mechanistic Insights
Round 1
Reviewer 1 Report
Very few papers in the literature deal with BiSbS3, and neither of them presents this compound associated with TiO2 and/or CdS. So this paper is very original. Moreover, the TiO2/CdS/BiSbS3 ternary hydrid sounds promising for the targeted application, i.e. development of photoanodes for solar water spliting.
In spite of good novelty and scientific interest, some improvements should be done.
- The last paragraph of the introduction is more like an abstract or a part of conclusion containing striking results. This paragraph should be changed to introduce the methodology.
- The third paragraph on page 9 (from line 208 to line 220) has to be changed due to the difference of trends for chronoamperometry for the 3 samples in figure (5d) is not obvious. So this paragraph should be tempered.
- "TiO2, CdS, BiSbS3 combined" in line 231 on page is not really clear.
- the caption of figure 5e is missing
- in the supporting information, purities of chemicals should be given.
Lastly, some sentences have to be corrected due to bad form:
- In figure 1, "TiO2-BiSbS3" should be changed into "TiO2/BiSbS3" to be the same writing as everywhere else in the paper for that binary compound.
- Caption of figure 2: "red color is corresponds" should be changed into "red color corresponds"
- line 141 on page 5: "that" should be removed
- line 148 on page 5: "well" is not suitable
- line 169 on page 6: "are analyzed" should be changed into "were analyzed"
- caption of figure 4: "are correspondence" should be changed into "correspond"
- line 196 on page 9: "of" or "for" should be removed
- line 205 on page 9: "plays" should be changed into "play"
- in caption of figure 5: "Photocatalytic of fabricates electrodes" should be changed into "Photocatalytic properties of fabricated electrodes"
- what does mean "furtur" in line 238 on page 10?
- line 238 on page 10: "are also analyzed" should be changed into "were also analyzed"
- lines 239 on page 10, 243 on page 11, 248 on page 11 and 253 on page 11: MS should be written the same way
- line 240 on page 10: "slopt" and "hs" have to be corrected
- line 241 on page 10: "netween" has to be corrected
- line 246 on page 11: "supports" has to be changed into "support"
- lines 257 and 258 on page 11: "to promote measure" is not correct
- line 263 on page 11: the sentence "whereas... electrodes." should be written differently.
- lines 274 and 275 on page 11: "In supporting... in Fig S11a-c." should be written differently.
- line 298 on page 12: "electron" should be changed into "electrons"
- line 300 on page 12: "gives" should be changed into "give"
- line 205 on page 12: "Fabrication FTO..." should be changed into "Fabrication of FTO..."
- line 324 on page 13: "density" should be changed into "densities"
- line 325 on page 13: "better" is missing between "and" and "PEC"
- line 331 on page 13: please correct "it" instead of "its", "enhances" instead of "enhance" and "suppresses" instead of "suppress"
- some spaces should be removed at many places in the paper (line 147 on page 5, line 173 on page 7, line 185 on page 9, line 270 on page 11)
Author Response
Response to the reviewer comment are attached.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The authors reported an interesting work using p-n heterojunction TiO2/CdS/BiSbS3 ternary hybrid composites for photoelectrochemical water splitting. The work is well presented and organized. However, there are still some flaws in experiments, references, and introduction. Therefore, I suggest a major revision before publication. The following questions must be addressed.
1. Figure 1, what’s the “A” on y axis stands for? I suggest authors giving the abbreviation.
2. How did authors get the Tauc plot. The equations and description should be added into supporting information.
3. Following the question 2, are those materials indirect or direct bandgap? How do authors know?
4. The introduction need to be expanded a bit to talk about the advantages of heterojunction catalysts should be further introduced, such as preventing the back charge transfer and enhanced light absorption. Some recent important examples of heterojunction catalysis (https://doi.org/10.1021/acsmaterialslett.1c00785; https://doi.org/10.1039/C5CC05211D)must be cited.
5. The authors claimed “The usual H2 production as a function of time from TiO2/BiSbS3, TiO2/CdS and TiO2/CdS/BiSbS3 photoanodes were examined in three-electrode system at 1.23 V vs RHE in a neutral medium (Na2SO4) as shown in Fig. S7.” But Figure S7 is HRTEM data, and I did not find the catalysis data.
6. I did not find the full name of “LSV” in the paper.
7. Is it possible to give the EDS mapping? Since from current SEM/TEM images it is hard to tell the TiO2 NPs.
8. What’s the ratio of each component in the TiO2/CdS/BiSbS3 ternary composites? Why did authors choose this ratio? Would the ratio influence the PEC performance?
Author Response
Please see the attachment.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Despite the fact that authors didn't really changed the last paragraph of the introduction as requested (which is only a question of form), the paper is acceptable in the present form due to all other requested changes were corrected.
Reviewer 2 Report
The revised manuscript looks good and the authors indeed made efforts. I suggest publishing this very good work.
One minor suggestion is, ref 48 can also be added after " Heterojunction for- mation strategy has gained attention due to they can effectively reduce the rate of electron- hole recombination.", together with ref 47 to support the claim.
