石墨烯可控发光研究

发布时间：2018-06-29 01:53

  本文选题：氧化石墨烯 + 石墨烯量子点　； 参考：《贵州大学》2017年硕士论文

【摘要】：本文首先研究了氧化石墨烯的制备工艺,通过改进Hummers法制备得到氧化石墨烯。得到的氧化石墨烯,通过了XRD、TEM及拉曼光谱表征,证明了其优良的性能。利用制得的氧化石墨烯作为前驱体,采用水热合成法,进一步研究制备了石墨烯量子点。得到的石墨烯量子点在320nm波长的激发光激发下,发射出435nm波长的蓝光。通过AFM测试看到,量子点的尺寸均在15-50nm大小,厚度约为3-5nm,这说明水热切割后的量子点同样保持了石墨烯的二维少层结构。对其水热制备工艺进行了研究发现,石墨烯量子点在9小时水热时间、24小时透析时间及140℃水热温度条件下,制备得到的石墨烯量子点荧光强度最强。采用最优制备参数得到的石墨烯量子点其荧光强度约为改进前的3倍,同时在6个月的静置后其荧光强度几乎未发生变化,说明得到的石墨烯量子点有着很好的稳定性。实现了工艺可控后,选择半胱氨酸掺杂对峰位可控进行了研究。通过利用水热条件发生缩合反应,将半胱氨酸的含氮硫基团键合在石墨烯量子点上,从而改变其发射波长。研究还发现,半胱氨酸在水热环境下会与自身发生反应,聚合形成新的量子点,其激发与发射光谱的峰位分别位于320nm及435nm处,与石墨烯量子点基本相同。通过调控半胱氨酸和氧化石墨烯的用量比,我们可以控制得到的量子点发射光谱峰位在390nm到435nm间有规律的变化,实现峰位可控。
[Abstract]:In this paper, the preparation process of graphene oxide was studied, and graphene oxide was prepared by improved Hummers method. The obtained graphene oxide was characterized by TEM and Raman spectra. Graphene oxide quantum dots were prepared by hydrothermal synthesis using graphene oxide as precursor. The obtained graphene quantum dots emit blue light of 435nm wavelength under the excitation of 320nm wavelength. The results show that the size of the QDs is about 3-5 nm and the size of the QDs is about 3-5 nm, which indicates that the hydrothermally cut QDs also maintain the two-dimensional structure of graphene. It was found that the highest fluorescence intensity of graphene quantum dots was obtained under the conditions of 9 hours hydrothermal time, 24 hours dialysis time and 140 鈩，

本文编号：2080304