Two‐Step Oxidation Synthesis of Sulfur with a Red Aggregation‐Induced Emission

作者：Dr. Zhenguang Wang; Chuanchuan Zhang; Henggang Wang; Dr. Yuan Xiong; Dr. Xinjian Yang; Dr. Yu‐e Shi; Prof. Andrey L. Rogach

来源：Angewandte Chemie, 2020, 132(25): 10083-10088.

DOI：10.1002/ange.201915511

• Aggregations-induzierte Emission
• Elementarer Schwefel
• Oxidation
• Phosphoreszenz
• Sauerstoffleerstellen

Sulfur is not normally considered a light‐emitting material, even though there have been reports of a dim luminescence of this compound in the blue‐to‐green spectral region. Now, it is shown how to make red‐emissive sulfur by a two‐step oxidation approach using elemental sulfur and Na\u003csub\u003e2\u003c/sub\u003eS as starting materials, with a high photoluminescence quantum yield of 7.2 %. Polysulfide is formed first and is partially transformed into Na\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e in the first step, and then turns back to elemental S in the second step. The elevated temperature and relatively oxygen‐deficient environment during the second step transforms Na\u003csub\u003e2\u003c/sub\u003eS\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e into Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e3\u003c/sub\u003e incorporated with oxygen vacancies, thus resulting in the formation of a solid‐state powder consisting of elemental S embedded in Na\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e3\u003c/sub\u003e. It shows aggregation‐induced emission properties, attributed to the influence of oxygen vacancies on the emission dynamics of sulfur by providing additional lower energy states that facilitate the radiative relaxation of excitons.