Selective detection of Fe 3+ ion using Zn 2 TiO 4 through fluorescence quenching probes

Abstract

In the present work, rutile-free Zn2TiO4 has been synthesized by the solid-state method using TiO2 as hydrated titania and ZnO of 1:2 molar ratio. The reaction mixture was calcined at different temperature ranges 550 oC to 950 oC. The phase evolution was identified by Raman spectroscopy, Fourier-transform infrared spectroscopy and X-ray diffraction methods. Scanning electron microscopy was used to study the morphology of the material, which showed irregular micron-sized and aggregated particles. Upon calcination at 950 oC, rutile-free, pure cubic Zn2TiO4 was obtained as evidenced by the aforementioned spectral analysis. The optical bandgap of the calcined products was calculated using UV-Visible diffuse reflectance spectra, which were found to be in the range of 3.55 to 3.85 eV. The fluorescent emission characteristics of the Zn2TiO4, and their quenching effects by adding various metal ions, owing to the formation of complexes between the metal ions and the surface of the Zn2TiO4, were investigated. The sensing properties were also evaluated using the standard Stern–Volmer quenching model. The results showed that Zn2TiO4 possesses high sensitivity and selectivity towards iron ions.