تقرير
Patterning edge-like defects and tuning defective areas on the basal plane of ultra-large MoS$_{2}$ monolayers toward hydrogen evolution reaction
| العنوان: | Patterning edge-like defects and tuning defective areas on the basal plane of ultra-large MoS$_{2}$ monolayers toward hydrogen evolution reaction |
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| المؤلفون: | Florindo, Bianca Rocha, Hasimoto, Leonardo H., de Freitas, Nicolli, Candiotto, Graziâni, Lima, Erika Nascimento, de Lourenço, Cláudia, de Araujo, Ana B. S., Ospina, Carlos, Bettini, Jefferson, Leite, Edson R., Lima, Renato S., Fazzio, Adalberto, Capaz, Rodrigo B., Santhiago, Murilo |
| المصدر: | J. Mater. Chem. A, 2023,11, 19890-19899 |
| سنة النشر: | 2023 |
| المجموعة: | Condensed Matter |
| مصطلحات موضوعية: | Condensed Matter - Materials Science |
| الوصف: | The catalytic sites of MoS$_{2}$ monolayers towards hydrogen evolution are well known to be vacancies and edge-like defects. However, it is still very challenging to control the position, size, and defective areas on the basal plane of Mo$S_{2}$ monolayers by most of defect-engineering routes. In this work, the fabrication of etched arrays on ultra-large supported and free-standing MoS$_{2}$ monolayers using focused ion beam (FIB) is reported for the first time. By tuning the Ga+ ion dose, it is possible to confine defects near the etched edges or spread them over ultra-large areas on the basal plane. The electrocatalytic activity of the arrays toward hydrogen evolution reaction (HER) was measured by fabricating microelectrodes using a new method that preserves the catalytic sites. We demonstrate that the overpotential can be decreased up to 290 mV by assessing electrochemical activity only at the basal plane. High-resolution transmission electron microscopy images obtained on FIB patterned freestanding MoS$_{2}$ monolayers reveal the presence of amorphous regions and X-ray photoelectron spectroscopy indicates sulfur excess in these regions. Density-functional theory calculations provide identification of catalytic defect sites. Our results demonstrate a new rational control of amorphous-crystalline surface boundaries and future insight for defect optimization in MoS$_{2}$ monolayers. Comment: 10 pages, 5 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1039/D3TA04225A |
| URL الوصول: | http://arxiv.org/abs/2311.04413 |
| رقم الأكسشن: | edsarx.2311.04413 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1039/D3TA04225A |
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