ChemInform Abstract: Structural and Optical Properties of Zinc Titanates Synthesized by Precipitation Method.

Abstract

Structural and Optical Properties of Zinc Titanates Synthesized by PrecipitationMethod. -ZnTiO 3 is precipitated from an equimolar mixture of TiCl3 and ZnCl2 in 12% aq. HCl solution (pH 1.4) by addition of 1 M NaOH up to pH 7. The dark blue mixture of Zn(OH) 2 and Ti(OH)3+x is further oxidized by air to white ZnTi(OH)6 before being calcined (SiC oven, gradual heating between 100 and 1000 C, 2 h each). With increasing calcination temperature, the amorphous compound turns into crystalline cubic ZnTiO 3 (600 C). Partial phase transformation into hexagonal ilmenite-type ZnTiO3 is observed between 700 and 900 C. At 1000 C both cubic and hexagonal ilmenite phases decompose into cubic Zn 2TiO4 and rutile TiO2. Calculated optical bandgaps from diffuse reflectance spectra are in the range of 3.59 to 3.84 eV depending on the calcination temperature. -(BUDIGI, L.; NASINA*, M. R.; SHAIK, K.; AMARAVADI, S.; J. Chem. Sci. (Bangalore, India) 127 (2015) 3, 509-518, http://dx.doi.org/10.1007/s12039-015-0802-5 ; Mater. Phys. Div., VIT Univ., Vellore 632 014, Tamilnadu, India; Eng.) -J. Schramke 28-015