Obtaining Quantum Dots of Graphene from Partially Unzipped Multi-Walled Carbon Nanotubes

摘要

Emitted nanostructures are very attractive because of their widely used in optoelectronic devices,and in biomedicine as biological markers.Consider nanostructured forms of carbon such as fullerene,single-walled carbon nanotubes(SWCNTs)and multi-walled carbon nanotubes(MWCNTs),graphene,which have many properties that differ from their bulk counterpart.Recently it has been reported that carbon nanotubes [1] and graphene nanoparticles in special condition [2] effectively emit in the visible range.Using some kind of oxidizing effect applied to nanotubes,it is possible to longitudinally unzipped MWCNTs and obtains graphene sheets with the corresponding number of layers [3].By controlling the process of unzipping nanotubes,it is also possible to obtain MWCNTs with a defective structure or,as they are also called,partially unzipped multi-walled carbon nanotubes(PUMWCNTs).Unusual electronic properties of PUMWCNTs with a structure called a chair were discovered,depending on the degree of unzipping of such nanotubes.The literature describes various methods for unzipping nanotubes,which differ only in the method of exposure to multi-walled carbon nanotubes leading to the unzipping of nanotubes or the possible creation of quantum dots.In [1] the authors reported about a method for producing carbon nanocrystals emitting a strong blue glow after electrochemical treatment of MWCNTs.In our previous works,the possibility of the controlled opening of MWCNTs was shown [3].Therefore,we investigated the most promising,in our opinion,electrochemical method for the synthesis of PUMWCNTs [4].We have proposed a method of ultrasonic crushing of PUMWCNTs.The aim of our work was to apply the electrochemical synthesis for the PUMWCNTs production and after it application of ultrasonic crushing technology for luminescent graphene quantum dots obtaining.