Synthesis and Characterisation of Methyl Violet/Cyclodextrin Doped ZnO Nanocrystals

Methyl violet/ cyclodextrin doped on ZnO nanocrystals were synthesized and characterized by various spectral and microscopic methods. The effect of different polarity of the solvents, α-cyclodextrin (α-CD) and β-cyclodextrin (β-CD) on MV were studied by various spectral methods. The inclusion behaviour of MV on both CDs were determined by PM3 method. Doping effect of MV/CD on ZnO nano investigated by UV-visible, fluorescence, FTIR, DTA, XRD, FE-SEM and TEM methods. MV molecule exhibits dual emission in all the solvents, α-CD and β-CD while three absorption maxima noticed in the ground state. The normal Stokes shifted band was originated from the locally excited state and the large Stokes shifted band was due to the emission from a twisted intramolecular charge transfer (TICT) state. Presence of isosbestic point suggest 1:1 inclusion complex is formed. HOMO-LUMO gap for MV/β-CD inclusion complex was more negative, which support that this complex is more stable than MV/α-CD inclusion complex. A red or blue shifted absorption and fluorescence maximum was seen in β-CD/MV/ZnO nanocrystals than MV/CD. Nanoparticle size was measured by TEM-EDS and X-RD methods. TEM image showed nanocrystals are formed in ZnO/MV/β-CD.