Defect‐Rich Molybdenum Sulfide Quantum Dots for Amplified Photoluminescence and Photonics‐Driven Reactive Oxygen Species Generation

Defect‐Rich Molybdenum Sulfide Quantum Dots for Amplified Photoluminescence and Photonics‐Driven Reactive Oxygen Species Generation

Advanced Materials

10.1002/adma.202200004

http://dx.doi.org/10.1002/adma.202200004

Houjuan Zhu, Wenyan Zan, Wanli Chen, Wenbin Jiang, Xianguang Ding, Bang Lin Li, Yuewen Mu, Lei Wang, Slaven Garaj, David Tai Leong

Mechanical Engineering, General Materials Science, Mechanics of Materials

11 June 2022

Zhu, H., Zan, W., Chen, W., Jiang, W., Ding, X., Li, B. L., Mu, Y., Wang, L., Garaj, S., & Leong, D. T. (2022). Defect‐Rich Molybdenum Sulfide Quantum Dots for Amplified Photoluminescence and Photonics‐Driven Reactive Oxygen Species Generation. Advanced Materials, 34(31). Portico. https://doi.org/10.1002/adma.202200004

AbstractTransition metal dichalcogenide (TMD) quantum dots (QDs) with defects have attracted interesting chemistry due to the contribution of vacancies to their unique optical, physical, catalytic, and electrical properties. Engineering defined defects into molybdenum sulfide (MoS2) QDs is challenging. Herein, by applying a mild biomineralization‐assisted bottom‐up strategy, blue photoluminescent MoS2 QDs (B‐QDs) with a high density of defects are fabricated. The two‐stage synthesis begins with a bottom‐up synthesis of original MoS2 QDs (O‐QDs) through chemical reactions of Mo and sulfide ions, followed by alkaline etching that creates high sulfur‐vacancy defects to eventually form B‐QDs. Alkaline etching significantly increases the photoluminescence (PL) and photo‐oxidation. An increase in defect density is shown to bring about increased active sites and decreased bandgap energy; which is further validated with density functional theory calculations. There is strengthened binding affinity between QDs and O2 due to lower gap energy (∆EST) between S1 and T1, accompanied with improved intersystem crossing (ISC) efficiency. Lowered gap energy contributes to assist e−–h+ pair formation and the strengthened binding affinity between QDs and 3O2. Defect engineering unravels another dimension of material properties control and can bring fresh new applications to otherwise well characterized TMD nanomaterials.

Publisher Copyright

This research / project is supported by the National Research Foundation, Prime Minister’s Office, Singapore - Competitive Research Program
Grant Reference no. : NRFCRP13-2014-03

This research / project is supported by the National University Singapore (NUS) - Reimagine Grant
Grant Reference no. : R279000627114

This is the peer reviewed version of the following article: Zhu, H., Zan, W., Chen, W., Jiang, W., Ding, X., Li, B. L., Mu, Y., Wang, L., Garaj, S., & Leong, D. T. (2022). Defect‐Rich Molybdenum Sulfide Quantum Dots for Amplified Photoluminescence and Photonics‐Driven Reactive Oxygen Species Generation. Advanced Materials, 34(31). Portico. https://doi.org/10.1002/adma.202200004, which has been published in final form at doi.org/10.1002/adma.202200004. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

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