Institute of Environmental Science, and School of Chemistry and Chemical Engineering , Shanxi University , Taiyuan 030006 , China.
Department of Chemistry , Washington State University , Pullman , Washington 99164 , United States.
Langmuir. 2018 Oct 30;34(43):12845-12852. doi: 10.1021/acs.langmuir.8b00939. Epub 2018 Oct 22.
Efficient room-temperature phosphorescence (RTP) of carbon dots (CDs) usually is seriously limited to appropriate solid matrix or introduced heavy atoms responsible for promoting intersystem crossing and suppress vibrational dissipation between singlet and triplet states. So, facile preparation efficient RTP of CDs with nonmatrix is still a highly difficulty and challenging task. Here, we first reported a subtle strategy to induce highly efficient free-matrix RTP of nitrogen-doped CDs (NCDs). The NCDs are composed of a core and hydrophilic surface of polyaspartic acid chains arising from high-temperature polymerization by a one-pot heating treatment of l-aspartic acid and d-glucose. The obtained NCDs have an ultralong phosphorescence lifetime of 747 ms and a high phosphorescence quantum yield (PQY) of 35% under 320 nm excitation in air. To the best of our knowledge, the PQY is currently the highest values recorded for RTP of CDs. The facile preparation and unique optical features offer these NCDs potential application in numerous applications, such as anticounterfeiting and white light-emitting diodes.
高效的室温磷光（RTP）通常严重依赖于合适的固态基质或引入重原子来促进系间窜越并抑制单重态和三重态之间的振动耗散。因此，制备高效的无基质室温磷光碳点仍然是一项极具挑战性的任务。在这里，我们首次报道了一种诱导高效的氮掺杂碳点（NCDs）自由基质 RTP 的巧妙策略。NCDs 由聚天冬氨酸链的核心和亲水性表面组成，这是通过将 L-天冬氨酸和 D-葡萄糖在一锅热处理中高温聚合而成的。在空气中，以 320nm 激发时，所获得的 NCDs 的磷光寿命长达 747ms，磷光量子产率（PQY）高达 35%。据我们所知，这是目前 RTP 碳点记录的最高 PQY 值。其简便的制备方法和独特的光学特性为这些 NCDs 在防伪和白光发光二极管等众多应用中提供了潜在的应用。
