Fluorescent carbon dots (CDs) have been reported as an artificial antenna to amplify the harvesting ability of light and enhance photosynthesis in plants. However, the main mechanism of this promotive effect and contributions of CDs’ structure are unclear. Herein, CDs and nitrogen (N)-doped CDs (N-CDs) with blue fluorescence were synthesized, and they could promote photosynthesis and growth of corn at an application concentration of 50 mg·L^–1 or lower, compared to the control. Foliar application of N-CDs (5 mg·L^–1) on corn could increase the net photosynthesis rate (21.51%), carbohydrate content (66.43% in roots and 42.03% in shoots), fresh weight (24.03% in roots and 34.56% in shoots), and dry weight (72.30% in roots and 55.75% in shoots), which were much higher than those of CDs. Principal component analysis and density functional theory calculation demonstrated that, compared with undoped CDs, N doping enhanced the light conversion and electron supply via altering the structure of CDs, making N-CDs effective light conversion materials and electron donors to promote the photoelectron transfer rate. Furthermore, foliar application of N-CDs could increase the yield and 1000-grain weight by 24.50 and 15.03%, respectively. Therefore, the application of N-CDs could be a promising approach for increasing agricultural production.

中文翻译：

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掺氮碳点增加光转换和电子供应以改善玉米光系统和产量

据报道，荧光碳点 (CD) 是一种人造天线，可放大光的收集能力并增强植物的光合作用。然而，这种促进作用的主要机制和 CD 结构的贡献尚不清楚。在此，合成了具有蓝色荧光的CDs和氮(N)掺杂CDs(N-CDs) ，与对照相比，它们在50 mg·L ^–1或更低的施用浓度下可促进玉米的光合作用和生长。叶面喷施 N-CDs (5 mg·L ^–1）对玉米的净光合速率（21.51%）、碳水化合物含量（根66.43%、枝条42.03%）、鲜重（根24.03%、枝条34.56%）和干重（根72.30%）和 55.75% 的芽），远高于 CD。主成分分析和密度泛函理论计算表明，与未掺杂的CD相比，N掺杂增强了光转换和电子供给通过改变CDs的结构，使N-CDs成为有效的光转换材料和电子供体，以提高光电子转移率。此外，叶面喷施 N-CDs 可分别提高产量和千粒重 24.50% 和 15.03%。因此，N-CDs 的应用可能是提高农业产量的一种有前景的方法。