Xia Chunlei, Zhu Shoujun, Zhang Shi-Tong, Zeng Qingsen, Tao Songyuan, Tian Xuzhou, Li Yunfeng, Yang Bai
State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, P. R. China.
Key Laboratory of Organ Regeneration and Transplantation of the Ministry of Education, The First Hospital of Jilin University, Changchun 130061, P. R. China.
ACS Appl Mater Interfaces. 2020 Aug 26;12(34):38593-38601. doi: 10.1021/acsami.0c11867. Epub 2020 Aug 12.
Recently, the room-temperature phosphorescence (RTP) properties of carbon dots (CDs) have attracted significant interest. However, the regulation of RTP emission faces great challenges because of untunable emissive lifetime and wavelength. Here, ultrahigh-yield acrylamide-based N-doped carbonized polymer dots (AN-CPDs) with ultralong RTP lifetime are synthesized by a one-step hydrothermal addition polymerization and carbonization strategy. The RTP lifetime and wavelength of the proposed AN-CPDs can be regulated by changing the carbonization degree. Thus, the AN-CPDs' RTP lifetimes are in the range of 61.4-466.5 ms, while the RTP emission wavelengths vary from 485 to 558 nm. Further experiment and theoretical calculation proved that RTP can be attributed to the polymer/carbon hybrid structure and nitrous functional groups as the molecular state related emission centers. Supramolecular cross-linking in the aggregated state is vital for the RTP emission of the AN-CPDs by restricting the nonradiative transition of the triplet excitons. AN-CPDs of different RTP lifetimes can be applied to time-resolved multistage information encryption and multistage anticounterfeiting. This work facilitates the optical regulation and application potential of CDs and provides profound insights into the effect of the polymer/carbon hybrid structure on the properties of CDs.
最近，碳点（CDs）的室温磷光（RTP）特性引起了广泛关注。然而，由于发射寿命和波长不可调，RTP发射的调控面临巨大挑战。在此，通过一步水热加成聚合和碳化策略合成了具有超长RTP寿命的超高产率丙烯酰胺基N掺杂碳化聚合物点（AN-CPDs）。所制备的AN-CPDs的RTP寿命和波长可通过改变碳化程度来调控。因此，AN-CPDs的RTP寿命在61.4 - 466.5 ms范围内，而RTP发射波长在485至558 nm之间变化。进一步的实验和理论计算证明，RTP可归因于聚合物/碳杂化结构和亚硝基官能团作为分子态相关的发射中心。聚集态的超分子交联通过限制三重态激子的非辐射跃迁对AN-CPDs的RTP发射至关重要。不同RTP寿命的AN-CPDs可应用于时间分辨多级信息加密和多级防伪。这项工作促进了CDs的光学调控和应用潜力，并为聚合物/碳杂化结构对CDs性能的影响提供了深刻见解。
