Synthesis and characterization of Fe(III)-doped ceramic membranes of titanium dioxide and its application in photoelectrocatalysis of a textile dye

Abstract

______________________________________________________________________________Pure and Fe(III)-doped TiO 2 suspensions were prepared by the sol gel method with the use of titanium isopropoxide (Ti(OPri) 4 ) as precursor material. The properties of doped materials were compared to TiO 2 properties based on the characterization by thermal analysis (TG-DTA and DSC), X-ray powder diffractometry and spectroscopy measurements (FTIR). Both undoped and doped TiO 2 suspensions were used to coat metallic substrate as a mean to make thin-film electrodes. Thermal treatment of the precursors at 400°C for 2 h in air resulted in the formation of nanocrystalline anatase TiO 2 . The thin-film electrodes were tested with respect to their photocatalytic performance for degradation of a textile dye in aqueous solution. The plain TiO 2 remains as the best catalyst at the conditions used in this report.

Effect of Moisture on Dopant Segregation in Solid Hosts

“…1 Although high-doping concentrations result in significant red shifts of the band gap, 20 they are seldom employed because of the limitations in solubility and the formation of recombination centers. 16,21 Although there have been many studies that have focused on optimizing the doping concentration to yield a select photophysical response, 16,22 the positioning of the dopant (substitution vs interstitial, surface vs bulk) in the host lattice still remains a synthetic challenge. The dopant spatial distribution is often ignored in the literature 1,23,24 despite the direct effect on the physical, chemical, optoelectronic, and magnetic properties of the nanoparticles (NPs).…”

Defect‐mediated optical properties of Fe‐substituted TiO2 nanoparticles

“…The less sharp peaks at 1645 and 1709 cm −1 reflect the OH flexion and Ti─OH groups 19 . The sharp peaks for all samples obtained at 1460 cm −1 ascribed to OH and Ti─OH vibrations 31 . The peaks at 1383 and 1170 cm −1 exhibit C─O stretching vibration due to Lewis acidity and residual organic 25,30 .…”

“…19 The sharp peaks for all samples obtained at 1460 cm −1 ascribed to OH and Ti─OH vibrations. 31 The peaks at 1383 and 1170 cm −1 exhibit C─O stretching vibration due to Lewis acidity and residual organic. 25,30 The transmittance bands between 400 and 1200 cm −1 had peaks about 588, 667, 968, and 1159 cm −1 due to Ti─O and Ti─O─Ti vibrations.…”