Why is TiO2 the best photocatalyst?
Titanium dioxide (TiO2) has been widely used as a photocatalyst in many environmental and energy applications due to its efficient photoactivity, high stability, low cost, and safety to the environment and humans.
Why is anatase a better photocatalyst than rutile model studies on epitaxial TiO2 films?
For anatase the activity increases for films up to ~5 nm thick, while rutile films reach their maximum activity for ~2.5 nm films already. This shows that charge carriers excited deeper in the bulk contribute to surface reactions in anatase than in rutile.
What is the refractive index of rutile mineral form of TiO2 at 589 nm?
2.613
| Rutile | |
|---|---|
| Refractive index | nω = 2.613, nε = 2.909 (589 nm) |
| Birefringence | 0.296 (589 nm) |
| Pleochroism | Weak to distinct brownish red-green-yellow |
| Dispersion | Strong |
How is photocatalytic activity measured?
The solution is decolourated in the process. Throughout the measurement, the colour concentration of the solution is measured by UV-vis spectroscopy. For the determination of the photocatalytic activity, the adsorption is measured. The same surface, without UV irradiation, serves as reference.
What is the speed of light in TiO2?
The energy of a photon at each wavelength can be defined as equations 1 and 2, where h is Planck’s constant (6.626 x 10−34 J·s or W·s2), c is the speed of light (2.998 x 108 m/s), and λ is the wavelength of the light source in nm.
What is refractive index of TiO2?
For a typical sample of TiO2 – Rutile the refractive index and extinction coefficient at 632.8 nm are 2.8736 and 0.
What is the difference between rutile and anatase titanium dioxide?
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.