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
复制标题
用于放大光致发光和光子驱动活性氧生成的富缺陷硫化钼量子点
DOI：
10.1002/adma.202200004
复制
发表时间：
2022
期刊：
影响因子：
--
通讯作者：
D. Leong
中科院分区：
文献类型：
--
作者：
Houjuan Zhu;Wen;Wanli Chen;Wenbin Jiang;Xianguang Ding;Bang Lin Li;Yuewen Mu;Lei Wang;S. Garaj;D. Leong
具有缺陷的过渡金属二硫属化物（TMD）量子点（QD）由于空位对其独特的光学、物理、催化和电学性质的贡献而引起了人们的关注。将缺陷设计到硫化钼 (MoS2) 量子点中具有挑战性。在此，通过应用温和的生物矿化辅助自下而上策略，制造了具有高缺陷密度的蓝色光致发光MoS2量子点（B-QD）。两阶段合成首先通过Mo和硫离子的化学反应自下而上合成原始MoS2量子点（O-QD），然后进行碱性蚀刻，产生高硫空位缺陷，最终形成B-QD。碱性蚀刻显着增加光致发光（PL）和光氧化。缺陷密度的增加会导致活性位点增加和带隙能量降低；通过密度泛函理论计算进一步验证了这一点。由于 S1 和 T1 之间的间隙能量 (ΔEST) 较低，QD 和 O2 之间的结合亲和力增强，同时系统间窜越 (ISC) 效率提高。降低的间隙能量有助于协助 e−–h+ 对的形成以及增强 QD 和 3O2 之间的结合亲和力。缺陷工程揭示了材料性能控制的另一个维度，并且可以为其他已充分表征的 TMD 纳米材料带来全新的应用。
Transition 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.