We demonstrated a facile method to prepare photoluminescent graphene quantum dots using commercial polyacrylonitrile（PAN） based carbon fibers（CFs） as the raw material by facile chemical oxidation and exfoliation m...We demonstrated a facile method to prepare photoluminescent graphene quantum dots using commercial polyacrylonitrile（PAN） based carbon fibers（CFs） as the raw material by facile chemical oxidation and exfoliation method. The as-prepared GQDs with uniform size exhibit an excitation-independent photoluminescence behavior, which is similar to other semiconductor quantum dots. Moreover, when acting as catalyst the uniform GQDs have better activity for electrochemical oxidation of dopamine（DA） than graphene oxides（GOs）. The square wave voltammogram（SWV） peak values of GQDs are in good correspondence with DA concentrations and can act as a sensor of DA.展开更多
Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size dist...Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size distribution, whereas metal encapsulation in the CNO structure is disadvantageous for the same. Furthermore, the hollow CNOs are also advantageous for the synthesis of GQDs with a yellow-green hybrid luminescence and long-ranged excitation wavelength （λex）-independent photoluminescent （PL） behavior, in which the λex upper limit was 480 nm. These features enable safe sensing and cell tracking applications with a longer excitation wavelength in the visible light region. The potential applications of the synthesized GQDs as fluorescent sensing probes for detecting Cu（II） ions and non-toxic cell imaging under visible light excitation have been demonstrated. This means that sensing and bioimaging can be accomplished in the natural environment with no need for UV excitation. This work provides a reference to researchers in tailoring CNO structures in terms of their inner space to synthesize GQDs with the desired luminescence behavior.展开更多
基金Funded by the National Natural Science Foundation of China(21676070)the Hebei Training Program for Talent Project(A2015007)+1 种基金the Beijing National Laboratory for Molecular Sciences(20140120)the Special Project for Synthesis and Application of Graphene in Hebei University of Science and Technology(2015PT65)
文摘We demonstrated a facile method to prepare photoluminescent graphene quantum dots using commercial polyacrylonitrile（PAN） based carbon fibers（CFs） as the raw material by facile chemical oxidation and exfoliation method. The as-prepared GQDs with uniform size exhibit an excitation-independent photoluminescence behavior, which is similar to other semiconductor quantum dots. Moreover, when acting as catalyst the uniform GQDs have better activity for electrochemical oxidation of dopamine（DA） than graphene oxides（GOs）. The square wave voltammogram（SWV） peak values of GQDs are in good correspondence with DA concentrations and can act as a sensor of DA.
文摘Herein, carbon nano-onions （CNOs） with different structures have been investigated as precursors for the synthesis of graphene quantum dots （GQDs）. It was found that hollow CNOs yield GQDs with a uniform size distribution, whereas metal encapsulation in the CNO structure is disadvantageous for the same. Furthermore, the hollow CNOs are also advantageous for the synthesis of GQDs with a yellow-green hybrid luminescence and long-ranged excitation wavelength （λex）-independent photoluminescent （PL） behavior, in which the λex upper limit was 480 nm. These features enable safe sensing and cell tracking applications with a longer excitation wavelength in the visible light region. The potential applications of the synthesized GQDs as fluorescent sensing probes for detecting Cu（II） ions and non-toxic cell imaging under visible light excitation have been demonstrated. This means that sensing and bioimaging can be accomplished in the natural environment with no need for UV excitation. This work provides a reference to researchers in tailoring CNO structures in terms of their inner space to synthesize GQDs with the desired luminescence behavior.
