Using coal pitch as the carbon source to synthesize carbon dots (CDs), one of the most promising photoluminescence (PL) materials, can play an important role in the global demand for carbon neutralization. However, the reported CDs derived from coal pitch are mainly limited blue emission. Here, a new route to synthesize yellow-emissive CDs from coal pitch is developed by extracting the lightweight aromatic compounds from coal pitch and solvothermally treating the extracts in dichloromethane in the presence of a small amount of nitric acid and sulfuric acid. Notably, the obtained CDs exhibit excitation independent yellow emission, large Stokes shift and good photostability. The application of the CDs for luminescent solar concentrators (LSCs) is evaluated. It is found that the CDs can be well dispersed in polymethyl methacrylate (PMMA) matrix and fabricated transparent LSCs. The synthesized LSC (4 × 4 × 0.2 cm³) with the optimal CDs concentration exhibits an optical conversion efficiency (η_opt) of 3.31% and power conversion efficiency (η_PCE) of 1.95% under simulated sun light illumination (100 mW cm⁻²). This research offers a new strategy to synthesize new kind of CDs with desired performance by exploiting the native chemistries of coal pitch.

中文翻译：

---

煤沥青衍生的黄光碳点及其在发光太阳能聚光器中的应用

使用煤沥青作为碳源合成碳点（CD）是最有前途的光致发光（PL）材料之一，可以在全球碳中和需求中发挥重要作用。然而，报道的来自煤沥青的CD主要是有限的蓝光发射。在此，开发了一种从煤沥青中合成发黄光CD的新路线，即从煤沥青中提取轻质芳香族化合物，并在少量硝酸和硫酸存在下，在二氯甲烷中对提取物进行溶剂热处理。值得注意的是，所获得的碳点表现出与激发无关的黄光发射、大斯托克斯位移和良好的光稳定性。评估了 CD 在发光太阳能聚光器 (LSC) 中的应用。研究发现CDs可以很好地分散在聚甲基丙烯酸甲酯（PMMA）基质中并制成透明LSCs。具有最佳CD浓度的合成LSC（4 × 4 × 0.2 cm ^{3 ）在模拟太阳光照明（100 mW cm - ）下表现出3.31％的光学转换效率（} η _opt）和1.95％的功率转换效率（η _PCE）²）。这项研究提供了一种新策略，通过利用煤沥青的天然化学成分来合成具有所需性能的新型 CD。