Influence of counter-ions on the self-assembly of ZrO2 nanodisks

In three strong inorganic acidic conditions (HNO3, HCl and H2SO4), we have prepared a series of air-water interfacial zirconium dioxide (ZrO2) films at normal temperature via a self-assembly technique, by using dodecylbenzenesulfonic acid (DBSA) as template and Zr(OC4H9)(4) as precursor. X-ray diffraction (XRD), transmission electron microscope (TEM), UV-vis and fluorescence spectra have been used to characterize the ZrO2 films. Results show that a number of worm-like mesoporous nanodisks and ambiguously mesoporous nanodisks are observed in the ZrO2 films with NO3- and SO42- counter-ions, respectively. Remarkably, a great many perfect target-like multiring nanodisks are obtained in the ZrO2 sample with Cl- counter-ion. The self-assembly mechanism for ZrO2 nanodisks has been purposely discussed. A model based on the structural changes with respect to the influence of counter-ions on the self-assembly of ZrO2 nanodisks is therefore proposed. In addition, the structural changes for the ZrO2 films selfassembled at a higher temperature have been discussed in combination with the influence of counterions. (C) 2010 Elsevier Inc. All rights reserved.