# Size Adjustment of Zinc Oxide Nanostructures by Ultrasmall TiO2 Nanoparticles

## TL;DR

This study shows how adding tiny titanium dioxide particles can shrink zinc oxide nanorods, creating new nanostructures with potential for size-dependent applications.

## Contribution

A novel method to reduce ZnO nanorod size using am-TiO2 NPs through Zn(II) ion adsorption is introduced.

## Key findings

- am-TiO2 NPs significantly reduced the size of nr-ZnO through Zn(II) ion adsorption.
- Core@shell xZT materials with varying Zn/Ti molar ratios were successfully synthesized.
- Changes in size and structure were confirmed using FTIR, UV–vis, DLS, XRD, and TEM.

## Abstract

The interaction of positively charged ZnO nanorods (nr-ZnO) with negatively charged ultrasmall amorphous titanium
dioxide
(am-TiO2) nanoparticles (NPs) induced
a decrease in the nr-ZnO particle size while forming
nanostructured core@shell xZT materials (Zn/Ti molar
ratios of 16, 8, 4, 2, and 1). Such an unexpected outcome was assigned
to the high affinity and Zn­(II) ion adsorption capacity of am-TiO2 NP, as confirmed by the amount of Zn­(II)
ion in equilibrium in solution with am-TiO2 determined by ICP-OES and the respective adsorption isotherm profile.
The changes in size, morphology, and crystallinity compared to pure nr-ZnO were monitored by FTIR and UV–vis spectroscopy,
dynamic light scattering (DLS), and X-ray diffractometry (XRD) and
confirmed by transmission electron microscopy (TEM), suggesting a
promising strategy to explore size-dependent nanoscale phenomena in
ZnO-based nanomaterials.