Synthesis of Nanocrystalline Zinc Titanate Ecandrewsite by Sol-Gel: Optimization of Heat Treatment Condition for Red Shift Sensitization

Mohammad      Hossein Habibi; Maryam      Mikhak

Abstract

Nanocrystalline zinc titanate powders were produced at the short sintering time by a sol – gel route. The effect of heat treatment was studied on the crystallization behavior of zinc titanates. The prepared sols showed a narrow particle size the average grain size of 68 nm. The resulting nanopowders were characterized by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), transmission electron microscopy (TEM), scanning electron microscope (SEM), ultra-violet diffuse reflectance (UV-DRS) and thermogravimetry thermal analysis (TG-DTA). Results of thermal analysis by DTA and TG suggest that decomposition of the precursor proceeded via dehydration reaction, decomposition, combustion reaction and Ecandrewsite phase formation. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR) revealed that the optimum temperature for Ecandrewsite nanopowders calcination is 900 °C. With the increase of annealing temperature a new crystallite Ecandrewsite was formed and the ultraviolet light absorption efficiency was enhanced according to the UV – vis diffuse reflectance spectroscopy. The scanning electron microscope (SEM) observation shows that the nanopowders existed in the mode of polycrystalline structure and the average grain size 68 nm. A new absorption edge at higher wavelength (438 nm) for Ecandrewsite zinc titanate annealed at 900 °C is an indication that the nanopowder can absorb lights in the higher wavelength, and therefore they can more efficiently utilize lights for the photocatalytic purpose.

Keywords: Ecandrewsite, ZnTiO3, nanocrystal, nanoparticle, Sol-gel growth, Nanocrystalline, Zinc Titanate, Sol-Gel, Red Shift, Sensitization, Nanopowders, Absorption edge, Photocatalytic