氮-磷共掺杂石墨烯量子点制备及荧光特性

Preparation of Nitrogen-phosphorus Doped Graphene Quantum Dots and Fluorescence Properties

为了制备氮-磷共掺杂石墨烯量子点(N,P-GQDs)以探索其荧光性质的可调性,我们采用水热法以柠檬酸为碳源,六氯三聚磷腈为氮源、磷源,制备出了蓝色光致发光的氮-磷共掺杂石墨烯量子点(N,P-GQDs)。通过一些测试表征可以发现:制备的N,P-GQDs尺寸分布均匀,其横向平均尺寸约4.8 nm,晶格间距为0.24 nm,纵向平均厚度约0.95 nm。在光学性能测试中,观察到N,P-GQDs的荧光发射光谱对激发波长具有强的依赖性,其对可见光表现为较强的吸收性。通过量子产率公式计算得出N,P-GQDs的量子产率为10.4%。所制备出的N,P-GQDs具有优异的抗漂白能力及光学稳定性。通过调节样品的稀释浓度比例对N,P-GQDs的荧光性质的可调性进行研究,发现随着稀释倍数的增加,荧光强度先增加后下降。此外,发现制备的N,P-GQDs对Fe 3+产生强烈的复合作用,使N,P-GQDs荧光猝灭,由此建立了Fe 3+的传感分析方法。

In order to prepare nitrogen-phosphorus co-doped graphene quantum dots(N,P-GQDs)to explore the tunability of their fluorescent properties,we use hydrothermal method with citric acid as carbon source and phosphonitrilic chloride trimer as nitrogen source and phosphorus source.Blue photoluminescence nitrogen-phosphorus co-doped graphene quantum dots(N,P-GQDs)were prepared.The structure and composition of N,P-GQDs were characterized by TEM and AFM,and their fluorescence properties were detected and studied by UV-Vis and fluorescence spectroscopy.Through some test characterization,it can be found that the prepared N,P-GQDs have a uniform size distribution with a lateral average size of about 4.8 nm,a lattice spacing of 0.24 nm,and a longitudinal average thickness of about 0.95 nm.When the excitation wavelength of N,P-GQDs is 329 nm,the maximum emission wavelength is 426 nm.In the optical performance test,it was observed that the fluorescence emission spectrum of N,P-GQDs has a strong dependence on the excitation wavelength,and it exhibits strong absorption to visible light.The quantum yield of N,P-GQDs was calculated by the quantum yield formula to be 10.4%.The prepared N,P-GQDs have excellent anti-bleaching ability and optical stability.The adjustability of the fluorescence properties of N,P-GQDs was studied by adjusting the dilution ratio of the sample.It was found that the fluorescence intensity first increased and then decreased with the increase of the dilution factor.In addition,the fluorescence intensity of the N,P-GQDs could be greatly quenched by the addition of a small amount of Fe 3+,because the prepared N,P-GQDs have a strong complexing effect on Fe 3+.Through the experimental research,the sensing analysis method of Fe 3+was established.