Recently, carbon dots (CDs) have been recognized to be efficient catalysts for photo-activated reversible deactivation radical polymerization (RDRP) under visible light. However, the use of CDs to catalyze near infrared (NIR)-light-induced RDRP remains a challenge. Here, we prepared phosphorus- and nitrogen-codoped carbon dots (PN-CDs) with citric acid, L-tryptophan and diammonium hydrogen phosphate as the precursors. Compared with nitrogen-doped CDs, the absorption spectrum of the PN-CDs extended from the UV/visible region to the NIR after the introduction of the P atoms. The PN-CDs were used as the catalyst for photo-induced atom transfer radical polymerization (photoATRP). In addition to the predicted catalytic ability under irradiation with visible light, the PN-CDs exhibited unexpectedly high efficiency to catalyze polymerization under NIR (NIR-ATRP). The livingness of the NIR-ATRP was confirmed by the polymerization kinetics, chain extension and “on–off” light experiments; the versatility of the system was demonstrated using different monomers and solvents. Owing to the good penetration of NIR, the polymerization could be performed in the presence of an opaque barrier (i.e., pork skin). A crosslinked polymer gel was achieved by penetrating NIR-ATRP and showed photoluminescence properties and good deep-layered healing ability, demonstrating the potential of the PN-CD-catalyzed NIR-ATRP method in practical application.

中文翻译：

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磷氮共掺杂碳点 (PN-CD) 催化可见光-近红外光诱导的 photoATRP


最近，碳点（CD）被认为是可见光下光活化可逆失活自由基聚合（RDRP）的有效催化剂。然而，使用 CD 来催化近红外 (NIR) 光诱导的 RDRP 仍然是一个挑战。在这里，我们以柠檬酸、 L-色氨酸和磷酸氢二铵为前驱体制备了磷和氮共掺杂碳点（PN-CD）。与氮掺杂CD相比，引入P原子后，PN-CD的吸收光谱从紫外/可见光区域延伸至近红外区域。 PN-CDs 被用作光诱导原子转移自由基聚合（photoATRP）的催化剂。除了可见光照射下的预测催化能力外，PN-CD 在近红外 (NIR-ATRP) 下表现出出乎意料的高催化聚合效率。 NIR-ATRP的活性通过聚合动力学、扩链和​​“开关”光实验得到证实；使用不同的单体和溶剂证明了该系统的多功能性。由于NIR的良好渗透性，聚合可以在不透明屏障(即猪皮)存在下进行。通过穿透 NIR-ATRP 获得交联聚合物凝胶，并表现出光致发光特性和良好的深层愈合能力，展示了 PN-CD 催化的 NIR-ATRP 方法在实际应用中的潜力。