碳量子点已经成为具有巨大应用潜力的新一代光致发光纳米材料.在碳量子点的众多制备方法中,归属于"自上而下"法的酸回流处理含碳块体材料的技术有望实现碳量子点的宏量制备.其中,来源丰富、价格低廉原材料的选择是关键.本文中,我们详细考察了以富勒烯工业化生产过程中副产的炭灰为原料制备碳量子点的实际应用潜力.研究发现,在浓硝酸和浓硫酸作用下,富勒烯炭灰能够成功地转化为碳量子点.与用其他原料通过类似方法制备的碳量子点相比,富勒烯炭灰制备的碳量子点具有较高的荧光量子产率,达3%-5%.更为重要的是,光激发下富勒烯炭灰制备的碳量子点能够发射黄色荧光,从而在生命科学等领域具有潜在应用.进一步研究表明,富勒烯炭灰制备的碳量子点在很宽的pH值范围内具有稳定的光致发光行为,且能够抵御高的离子强度和长时间光照,进而拓宽了其在苛刻条件下的应用潜力. 

Carbon quantum dots (CQDs) have emerged as a new generation of photoluminescent nanomaterials with wide applications. Among the various synthetic routes for CQDs, the acid-refluxingmethod, which belongs to the group of “top-down” methods, offers the advantage of large-scale production of CQDs and uses cheap and abundantly available starting materials. In this study, we evaluated the potential of fullerene carbon soot (FCS), a by-product obtained during the synthesis of fullerene, as the starting material for CQD production. It was found that FCS can be successfully converted to CQDs in high production yield in mixed acids, i.e., concentrated HNO₃ and H₂SO₄, under mild conditions. The fluorescence quantum yield (Φ) of the as-produced CQDs is in the range of 3%–5%, which is the highest value for CQDs obtained from “top-down” methods. Importantly, the CQDs prepared by this method show emission in the yellow range of the visible light, which is advantageous for their various potential applications. Further investigations reveal that the CQDs are highly photostable over a wide pH range and show good resistance against ionic strength and long-termUV irradiation. This further expands their potential use under harsh conditions.