• 文献标题:   Solvent induced fluorescence enhancement of graphene oxide studied by ultrafast spectroscopy
  • 文献类型:   Article
  • 作  者:   ZHAO LT, CHEN JQ, HE XX, YU XT, YAN SJ, ZHANG SJ, PAN HF, XU JH
  • 作者关键词:   graphene oxide, time resolved fluorescence, transient absorption spectroscopy
  • 出版物名称:   CHEMICAL PHYSICS
  • ISSN:   0301-0104 EI 1873-4421
  • 通讯作者地址:   East China Normal Univ
  • 被引频次:   2
  • DOI:   10.1016/j.chemphys.2018.04.013
  • 出版年:   2018

▎ 摘  要

Femtosecond transient absorption (TA) spectroscopy combined with picosecond time resolved fluorescence (TRF) were used to reveal the fluorescence kinetics of graphene oxide (GO) in water, ethanol and water-ethanol mixtures. Size-independent fluorescence of GO were observed in water, and pH-dependent fluorescence spectra could be fitted well by a triple emission relaxation with peaks around 440 nm, 500 nm, and 590 nm respectively. The results indicate that polycyclic aromatic hydrocarbons (PAHs) linked by oxygen-containing functional groups dominate GO'S fluorescence emission. GO'S fluorescence quantum yield was measured to be 2.8% in ethanol but 1.2% in water. The three decay components fluorescence decay, as well as the transient absorption dynamics with an offset, confirmed this solvent induced fluorescence enhancement. GO'S Raman spectral signals showed that GO in ethanol has a smaller average size of PAHs than that of GO in water. Therefore, besides other enhancement effects reported in literatures, we proposed that solvents could also change the size of PAHs, resulting in a photoluminescence enhancement. Our experimental data demonstrates that GO'S quantum yield could be up to 2.8% in water and 8.4% in ethanol and this observation may help ones to improve GO'S photoluminescence efficiency as well as its applications in solution. (C) 2018 Elsevier B.V. All rights reserved.