Here a sustainable approach for the bottom-up fabrication of luminescent carbon dots (CDs) through a green synthetic route by using polymeric waste as a single precursor material is developed. Polylactide has been selected as a carbon-containing model polymeric waste because of its remarkable presence in the packaging field and its associated “white-pollution”. Spherical CDs with diameters of 3 nm have been synthesized through a one-pot hydrothermal reaction of water-dissolved polylactide oligomers (M_n = 1.200–1.900 g mol⁻¹) at mild temperatures. Chemical, structural, morphological and optical properties of the synthesized CDs have been studied. Results reveal that CDs consist of a carbonaceous nucleus having a sp² conformation with carboxyl and hydroxyl surface groups, making it dispersible in polar media. The optical features of obtained CDs depend on reaction conditions (time and temperature) and on the insertion of nitrogen groups within the CD structure. A proof of concept study of the application of the proposed approach for the production of luminescent CDs from commercial PLA lids for paper hot cups is also provided. The route here reported provides novel cues for a catalyst-free and organic-solvent-free industrial-scale fabrication of photoluminescent nanomaterials from actual polymeric waste as a viable non-toxic and cheap alternative to quantum dots and rare earth based nanophosphors.

在这里，开发了一种可持续的方法，通过使用聚合物废物作为单一的前体材料，通过绿色合成路线自底向上制造发光碳点（CD）。聚丙交酯因其在包装领域的显着存在及其相关的“白色污染”而被选为含碳示范聚合物废物。直径3 nm的球形CD通过在温和的温度下通过一锅水溶解的聚丙 交酯低聚物（M _n = 1.200–1.900 g mol ^-1）进行水热反应合成。已研究了合成CD的化学，结构，形态和光学性质。结果表明，CD包含具有sp ²的碳核。具有羧基和羟基表面基团的构象，使其可分散在极性介质中。获得的CD的光学特征取决于反应条件（时间和温度）以及CD结构中氮基的插入。还提供了关于从商业上用于纸杯的PLA盖子生产发光CD的方法的概念研究的概念证明。本文报道的途径为从实际的聚合物废物中无催化剂和无有机溶剂的工业规模生产光致发光纳米材料提供了新颖的线索，作为量子点和稀土基纳米磷光体的可行的无毒且廉价的替代品。