In Situ Preparation of 0D/2D Zn-Ag-In-S Quantum Dots/RGO Heterojunctions for Efficient Photocatalytic Hydrogen Production

Round 1

Reviewer 1 Report

The authors in this manuscript describe the synthesis and characterization of a ZAIS QDs/RGO-based composite for the efficient photocatalytic hydrogen production.

- Figure 3 line 119-121; The authors write "From the 119 enlarged figure of Figure 3b, we can see that the two characteristic peaks of C=O and C-O 120 have obvious enhancement compared with that of ZAIS QDs after adding RGO, and the 121 peak is the strongest when the RGO content is 30 μL." It's not clear what the authors are referring to, the most intense signals seem to be at 20 uL.

- Table 1; Why calculate T ave from life times of two different species? What does it mean? What do the A1 and A2 % values mean? Why are they so different from each other? And why are the absolute values so different between the three samples? The total doesn't add up to 100 so what percentages are they and what do they represent?

- How are QDs synthesized?

- In Figure 8 H+ is shown. Where does it come from? What are the conditions under which this reaction occurs?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The article In situ Preparation of 0D/2D Zn-Ag-In-S Quantum Dots/RGO Heterojunctions for Efficien Photocatalytic Hydrogen Production by Bangya Deng , Yalin Yang , Afaq Ullah Khan , Qitao Chen, Xianjin Wang , Tong Ren , Jiaji Li , Yanhong Liu , Lixia Li, Baodong Mao, presents advancement in solar hydrogen production by demonstrating that the in situ synthesis of zero-dimensional/two-dimensional (0D/2D) Zn-Ag-In-S quantum dots/reduced graphene oxide (ZAIS QDs/RGO) heterojunctions enhances photocatalytic activity and stability. The inclusion of 30 μL RGO increased the hydrogen production rate by 3.1 times compared to pure ZAIS QDs, while also showing superior stability over repeated cycles. Enhanced charge separation efficiency was attributed to the extended fluorescence lifetime and rapid charge transfer facilitated by the RGO. These findings underscore the potential of RGO in improving the performance of I-III-VI sulfide quantum dot-based photocatalysts.

Abstract

It provides a well-written summary of the research.

Introduction

Introduce the subject and provide a literature review.

Results and Discussion

Figure 1: XRD – the spectrum seems to have a lot of noise, a better spectrum with less noise should be provided. Additionally, the cubic phase planes should be identified withing the figure.

Figure 2: The TEM images are not very clear, and what is claimed by the authors is not clearly seen. Images with better resolution or magnification should be included.

Figure 5: The y axis of the figure should be µmol and not mmol.

Figure 7: The resolution of the image should be improved.

Recommendations:

1) It is highly recommended to study the bandgap of the photocatalysts by diffuse reflectance spectroscopy. With the values of the bandgap, a more comprehensive mechanism of the production of hydrogen via water splitting could be provided.

2) It is highly recommended to include a Table to compare the hydrogen production obtained by the authors with those obtained with other researchers that have worked with similar photocatalysts and conditions.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The authors responded clearly to all of my questions. The manuscript is now suitable for publication.

Reviewer 2 Report

Thank you for making the changes to the manuscript. The manuscript has been improved.