Abstract The thoroughly understanding of photoluminescence (PL) featuring with excitation-dependent emission (EDE) and excitation-independent emission (EIE) are critical for designing carbohydrate-derived carbon dots (CDs) with excellent PL characteristics. Herein, two types of xylan-derived CDs with EDE and EIE were facilely synthesized under the doping effect of NH4OH and polyethyleneimine, respectively. The investigation on optical properties, morphology, and chemical structure of these synthesized CDs revealed that both the EDE and EIE were heavily dependent on the surface states rather than the size and structure of carbogenic cores. Furthermore, the multiple energy levels induced by surface-contained C–OH, C–O–C, and C–O functionalities were responsible for the EDE, while the formation of plentiful C–N or C N like groups, which together with the decreased O-containing groups resulted in a uniform surface state that contained concentrated energy levels, thus generating the EIE behavior of xylan-derived CDs.

中文翻译：

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木聚糖衍生碳点的荧光机制：研究激发相关的发射行为

摘要 透彻理解具有激发依赖发射 (EDE) 和激发无关发射 (EIE) 的光致发光 (PL)，对于设计具有优异 PL 特性的碳水化合物衍生碳点 (CD) 至关重要。在此，分别在 NH4OH 和聚乙烯亚胺的掺杂作用下，轻松合成了两种具有 EDE 和 EIE 的木聚糖衍生 CD。对这些合成 CD 的光学性质、形态和化学结构的研究表明，EDE 和 EIE 都严重依赖于表面状态，而不是碳核的大小和结构。此外，由表面包含的 C-OH、C-O-C 和 C-O 官能团诱导的多能级是 EDE 的原因，同时形成了大量的 C-N 或 CN 类基团，