以聚对苯二甲酸乙二醇酯为前驱体的碳点制备及其应用

Preparation and application of carbon dots with polyethylene terephthalate as precursor

针对纺织废弃物的急剧增加以及随之带来的环境污染和石油资源枯竭问题,以聚对苯二甲酸乙二醇酯(PET)和磷酸氢二铵为原料,采用热解法制备了性能优异的磷氮元素掺杂PET基碳点。探究了PET基碳点的最优制备工艺及其形貌结构、化学结构和荧光性能等,探索了其在荧光防伪等方面的应用。得到最优制备工艺为:PET低聚物质量为5 g,磷酸氢二铵质量为2 g,反应温度为260℃,反应时间为18 h。该条件下制备的PET基碳点具有典型的激发波长依赖性,其最佳激发光波长为320 nm,最佳发射光波长为390 nm,荧光量子产率可达18.26%,平均荧光寿命为6.96 ns;PET基碳点具有稳定的水溶性和优良的抗干扰性,用其制成的荧光墨水、荧光粉与荧光琼脂在365 nm紫外光照射下均呈现出明亮的蓝色荧光。该PET基碳点在数据加密、防伪、成像、LED器件等方面存在巨大应用潜力,为废弃PET的高值回收利用提供了新的可能。

In response to the rapid increase in textile waste and the consequent environmental pollution and depletion of petroleum resources,using waste polyethylene terephthalate(PET)and ammonium dihydrogen phosphate as raw materials,phosphorus nitrogen doped PET based carbon dots were prepared by pyrolysis method.The optimal preparation process of PET based carbon dots and their morphology,chemical structure and fluorescent properties were studied,and their applications in fluorescent anti-counterfeiting were explored.The results showed that at the optimal conditions of the mass of PET oligomer of 5 g,the ammonium dihydrogen phosphate mass of 2 g,the reaction temperature of 260℃,and the reaction time of 18 h,the PET based carbon dots have a typical excitation wavelength dependence.The optimal excitation and emission wavelength is 320 nm and 390 nm respectively,and the fluorescence quantum yield can reach 18.26%.The average fluorescence lifetime is 6.96 ns.PET based carbon dots is stable in water solubility and excellent in anti-interference.The fluorescent inks,phosphors and fluorescent agar made from them all exhibit bright blue fluorescence under 365 nm ultraviolet light irradiation.The PET based carbon dots have huge application potential in data encryption,anti-counterfeiting,imaging,LED devices,and more,providing new possibilities for the high-value recycling of waste PET.