还原氧化石墨烯的发光性能

Luminescence properties of reduced graphene oxide

利用X射线衍射分析(XRD)、透射电镜(TEM)、X射线光电子能谱(XPS)、拉曼光谱(Raman)等测试方法表征了还原氧化石墨烯(rGO)的结构及成分,用紫外可见分光光谱仪和荧光光谱仪表征还原氧化石墨烯(rGO)水分散液的光学性能。光学性能分析表明:205~345 nm激发下,rGO的发光主要集中在350~500 nm的蓝紫光波段。0.1 mg/mL样品的发射波长在350~450 nm之间,且发射波长随着激发波长的增加发生红移,发光主要受sp^(2)团簇的量子尺寸的影响。0.01 mg/mL和0.005 mg/mL的样品,有385 nm和450 nm的两个发光中心,385 nm的发光峰随着激发波长的增加发生红移,归属于C=C键中π-π*跃迁以及sp^(2)团簇的量子尺寸效应,450 nm的发射峰随激发波长的增加变化不明显,归属于C=O中能级中电子-空穴对的非辐射跃迁。

The structure and composition of reduced graphene oxide(rGO)were characterized by X-ray diffraction analysis(XRD),transmission electron microscopy(TEM),X-ray photoelectron spectroscopy(XPS)and Raman spectroscopy(Raman).Optical performances of rGO in water were characterized by uv-vis spectropho-tometer and fluorescence spectrometer.The results show that the rGO emission is mainly concentrated in 350-500 nm range under 205-345 nm excitation.For 0.1 mg/mL sample,the emission is mainly in the range of 350-450 nm,and red shifted with the increase of excitation wavelength,which mainly affected by the sp^(2) cluster.For 0.01 mg/mL and 0.005 mg/mL samples,there are two emission centers located at 385 nm and 450 nm.The 385 emission has a red shift with the increase of excitation wavelength,which is attributed to theπ-π*transition in C=C bond and the quantum size effect of sp^(2) clusters.The 450 nm emission varies with the excitation wavelength not ob-viously,which may be caused by the non-radiative transition of C=O energy level.