Molecular layer-by-layer re-stacking of MoS2–In2Se3 by electrostatic means: assembly of a new layered photocatalyst

Journal article

2D-layered transition metal chalcogenides are useful semiconductors for a wide range of opto-electronic applications. Their similarity as layered structures offers exciting possibility to modify their electronic properties by creating new heterojunction assemblies from layer-by-layer restacking of individual monolayer sheets, however, the lack of specific interaction between these layers could induce phase segregation. Here, we employed a chemical method using n-BuLi to exfoliate MoS₂ and In₂Se₃ into their monolayer-containing colloids in solution. The bulky Se atoms can be selectively leached from In₂Se₃ during Li treatment which gives positively charged surface monolayers in neutral pH whereas the strong polarization of Mo–S with moderate S leaching gives a negatively charged surface. Specific interlayer electrostatic attraction during their selective assembly gives a controllable atomic AB-type of layer stacking as supported by EXAFS, STEM with super-EDX mapping, TAS/TRPL and DFT calculations. Using this simple but inexpensive bottom-up solution method, a new photocatalyst assembled from layers for photo water splitting can be tailor-made with high activity.

Authors: Ng, BKY; Wong, CCY; Niu, W; Garcia, HP; Li, Y

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Royal Society of Chemistry
• Journal: Materials Chemistry Frontiers
• Volume: 7
• Issue: 5
• Pages: 937-945
• Publication date: 2023-01-23
• Acceptance date: 2023-01-06
• DOI: 10.1039/D2QM01095J
• EISSN: 2052-1537
• Language: English