Effects of Ti-precursor concentration and annealing temperature on structural and morphological properties of TiO2 nano-aerogels synthesized in supercritical ethanol

Abstract

TiO 2 nano-aerogels are elaborated by using acid-modified sol-gel approach from titanium tetra isopropoxide under supercritical drying conditions of ethanol. The effects of Ti-precursor concentration and annealing temperature on structural and morphological properties of TiO 2 nanoparticles are investigated by XRD, infrared spectroscopy, SEM and specific surface area measurements. It was found, from XRD analysis, that pure anatase phase is obtained for the aerogels synthesized with various precursor concentrations. The increase of sol concentration leads to a slight and uniform variation of TiO 2 cell parameters. The specific surface area of aerogels particles decreases and the pore volume increases with increasing of Ti-concentration. The presence of Ti-O and Ti-O-Ti bonds is confirmed by FTIR measurements. EDAX analysis shows that TiO 2 nano-aerogels are oxygen rich. SEM images put into evidence the almost spherical elaborated particles with an enhanced agglomeration at high precursor concentration. With the increase of annealing temperature, the mixture of the phases did not happen and the pure anatase to pure rutile transition phase temperature is found to be around 900 °C. The Ti-O-C bonds disappear with annealing temperature. The heat treatment leads not only to the changes in crystal structure but also in morphology of the elaborated aerogels grains.

Systematic investigation of the influence of experimental conditions on TiO2 nanosheet structures

“…Besides shape, the surface area and pore volume can be modified by the precursor concentration. [30] In our case, with the variation of TTIP concentration, great changes occurs in the morphology. The reaction temperature and time is the same for these samples, therefore, such change in shape can only be induced by the kinetics.…”

“…As reported in literature [28,29], more TTIP benefits the crystalline structure of TiO2. Djouadi et al [30] reported that the rise of sol concentration could affect the TiO2 cell parameters. The precursor concentration can also affect the morphology.…”

Synergistic effects of Mg doping on TiO2 for improved toxic gas sensing performance at room temperature

“…Ti-O-Mg bond formation through Mg doping is believed to hinder grain growth, resulting in smaller crystallites [27]. Other parameters, such as micro-strain, dislocation density, lattice parameters, lattice volume, and dspacing [38,39] were determined and tabulated in table 2.…”

Growth of Nanocolumnar TiO2 Bilayer by Direct Current Reactive Magnetron Sputtering in Glancing-Angle Deposition Configuration for High-Quality Electron Transport Layer

“…The results of ATR spectroscopy are shown in Figure 3. In this characterization, two absorption bands can be identified that correspond to the Ti-O-Ti bond when there is an incidence of light with a wave number of 734 cm −1 [43,46] and a bond of Si-O for a wavenumber of 1106 cm −1 . An additional signal at 1240 cm −1 can be observed in For the three compact TiO 2 test samples that were deposited under the same sputtering atmosphere conditions (10 O 2 /40 Ar) under normal sputtering conditions, varying only the deposit power to 100, 120, and 140 W. The diffraction patterns showed a diffraction peak at an angle 2θ = 24.8 • as the principal maximum, and this peak corresponds to the signal of the plane (101) of the structure tetragonal anatase typical of TiO 2 .…”