基于废弃物核桃壳碳点的合成及其光致发光性能

Synthesis and Photoluminescence Properties of Waste Walnut Shell-based Carbon Dots

以核桃壳为碳源、氨水为添加剂,采用一步水热法制得碳点(CDs),讨论了反应温度和时间对CDs荧光性能的影响,得到实验的最佳适用条件为反应温度200℃、反应时间5h。合成的CDs平均粒径为3.0nm,发蓝光,表面含有羟基、羧基、酰胺基等含氧官能团,具有激发波长依赖的发射行为,发射光谱宽。CDs在紫外光连续照射10h表现出高的荧光稳定性,说明其可用于生物成像领域。

Carbon dots(CDs) were prepared by a one-step hydrothermal method with walnut shell as carbon source and ammonia solution as additive. The effects of reaction temperature and time on the fluorescent properties of CDs were explored in the experiment. The optimized reaction conditions were as follows: The carbon dots were synthesized at 200 ℃ for 5 h. The obtained CDs had the average diameter of 3.0 nm, emitting blue fluorescence. Their surfaces contained some functional groups such as hydroxyl groups, carboxyl groups, and amide groups. CDs also had excitation-dependent emission properties, showing broad visible light emission. CDs exhibited high fluorescence stability under ultraviolet irradiation for 10 h, indicating that they could be used in biological imaging fields.