What is difference between anatase and rutile?
The key difference among them is in their appearance. Anatase Titanium Dioxide is colorless, whereas Rutile Titanium Dioxide is usually found in dark red appearance. Rutile titanium dioxide is optically positive, whereas Anatase titanium dioxide is optically negative.
Why is rutile more stable than anatase?
Anatase has a larger band gap than rutile TiO2. While this reduces the light that can be absorbed, it may raise the valence band maximum to higher energy levels relative to redox potentials of adsorbed molecules.
What is the melting point of rutile?
1,843 °C
Titanium dioxide
| Names | |
|---|---|
| Density | 4.23 g/cm3 (rutile) 3.78 g/cm3 (anatase) |
| Melting point | 1,843 °C (3,349 °F; 2,116 K) |
| Boiling point | 2,972 °C (5,382 °F; 3,245 K) |
| Solubility in water | Insoluble |
What is the chemical formula for anatase?
TiO2
Anatase Mineral Data
| General Anatase Information | |
|---|---|
| Chemical Formula: | TiO2 |
| Composition: | Molecular Weight = 79.88 gm |
| Titanium 59.94 % Ti 100.00 % TiO2 | |
| Oxygen 40.06 % O |
Is rutile soluble in water?
The calculated solubility of rutile, anatase, and Ti(OH) 4 in the water solution at 20−320 °C is reported in Figure 1 (solid lines). The solubility of rutile is rather low and ranges between 2 × 10 −6 at 20 °C and 2 × 10 −4 mol/kg at 320 °C. …
What is the hardness of rutile?
6 – 6.5
Rutile Information
| Data | Value |
|---|---|
| Refractive Index | 2.62-2.90 |
| Colors | Black, gray, deep red, brownish red. Greenish (if Nb present), also bluish and violet. A variety rich in Cr is deep green. |
| Luster | Metallic to adamantine. |
| Hardness | 6 – 6.5 |
How is anatase formed?
Much anatase is formed by weathering of titanite, and it is itself altered to rutile; rutile paramorphs (replacements having the same outward shape) after anatase are common in the detrital deposits of Brazil and the Sanarka region of the Urals.
What is anatase structure?
Anatase is a metastable mineral form of titanium dioxide (TiO2). Anatase is always found as small, isolated and sharply developed crystals, and like the thermodynamically stable rutile (the more commonly occurring polymorph of titanium dioxide), it crystallizes in the tetragonal system.
Is anatase a crystalline?
4.2); anatase is optically negative whereas rutile is positive; and its luster is even more strongly adamantine or metallic-adamantine than that of rutile….
| Anatase | |
|---|---|
| Crystal habit | Pyramidal (crystals are shaped like pyramids), tabular (form dimensions are thin in one direction). |
| Twinning | Rare on {112} |
Why is the transition temperature of anatase to rutile delayed?
X-ray diffraction and Raman spectroscopy data show that anatase-to-rutile phase transition temperature is delayed by the presence of SiO 2, enabling single-anatase phase photoanodes for DSSCs. According to the measurements, photoanodes with 3% of SiO 2 result in improved efficiency, which is mainly related to increased surface area and dye loading.
How is the art of titania nanoparticles performed?
Anatase to rutile phase transformation (ART) of titania nanoparticles is observed at very low temperature (180 °C) just by introducing polyvinyl alcohol (PVA) during co-precipitation followed by hydrothermal synthesis.
How is the transition temperature of TiO2 delayed?
SiO 2 is found to form very small amorphous domains well dispersed in the TiO 2 matrix. X-ray diffraction and Raman spectroscopy data show that anatase-to-rutile phase transition temperature is delayed by the presence of SiO 2, enabling single-anatase phase photoanodes for DSSCs.