Anchoring zinc oxide quantum dots on functionalized multi-walled carbon nanotubes by covalent coupling

ZnO quantum dots (QDs) are anchored on multi-walled carbon nanotubes (MWCNTs) by a wet chemical self-assembling technique. The structure and properties of QDs/MWCNTs are also studied in detail. First, MWCNTs are functionalized with thiol by a series of chemical reactions. Fourier transform infrared spectroscopy is used to verify changes of chemical bonds on MWCNTs. At one time, quantum dots of ZnO alcogel are prepared by a sol–gel process. Finally, the functionalized MWCNTs (f-MWCNTs) are added into ZnO alcogels under ultrasonic condition or being magnetically stirred, and ZnO QDs/f-MWCNT composite is obtained by a self-assembling technique. A typical transmission electron microscopy image of the as-received ZnO QDs/f-MWCNT composite reveals that monodispersed ZnO QDs are anchored stably on functionalized MWCNTs. Moreover, photoluminescence spectrum and current–voltage curves display the special optoelectronic properties of this ZnO QDs/f-MWCNT hybrid.