Titanium dioxide (TiO2) semiconductor nanoparticles are one kind of important and promising photocatalysts in photocatalysis because of their unique optical and electronic properties. Their properties, which are determined by the preparation method, are very crucial in photocatalysis.

What are the uses of titanium dioxide nanoparticles?
Titanium dioxide nanoparticles are bright with high refractive index (n = 2.4) which makes them suitable for industry dealing with toothpaste, pharmaceuticals, coatings, papers, inks, plastics, food products, cosmetics and textile. Due to their self cleaning and antifogging property, they are used in the preparation of cloths, windows, tiles and anti-fogging car mirrors. Titanium dioxide nanoparticles also serve as environment sanitizing agent. They have wide applications, viz., reducing toxicity of dyes and pharmaceutical drugs; waste water treatment; reproduction of silkworm; space applications; food industries; etc., and so have immense industrial importance.

How do you make titanium dioxide nanoparticles?
The TiO2 can be obtained by placing a cleaned Ti metal plate in a 50 mL solution of 30 wt% H2O2 at 353 K for 72 h. Formation of crystalline TiO2 occurs via mechanism of dissolution precipitation and this phase can be controlled by addition of NaX (X = F−, Cl−, SO42−) inorganic salts.

There are other various techniques for preparing titanium dioxide nanoparticles and these include reverse micelles, the sol-gel process, the metal organic chemical vapor deposition (MOCVD), gas phase (aerosol) synthesis, wet-chemical synthesis by precipitation of hydroxides from salts, microemulsion-mediated methods and electrochemical synthesis. These methods can be divided into five general groups namely sol-gel, deposition methods, sonochemical and microwave-assisted methods, hydro/solvothermal methods and oxidation methods.

What are TiO2 nanotubes?
TiO2 nanotubes have been considered in photocatalysis including water splitting, the decomposition of pollutants, CO2 reduction, dye-sensitized solar cells, ion-insertion batteries, and in biomedicine as a coating of metallic implants and as a drug delivery system.

Is titanium dioxide nanoparticles safe?
The EU’s Scientific Committee on Consumer Safety (SCCS) approved nanometric titanium dioxide (in the three crystalline forms) to be considered safe for use in cosmetic products intended for application on healthy, intact or sunburnt skin.

Titanium dioxide nanoparticles used for research?
CD Bioparticles offers a variety of precisely engineered titanium dioxide nanoparticles with uniform size and shapes. Different crystal forms including amorphous, anatase and rutile titania nanoparticles are provided both in nanopowder and dispersion. Our titania nanoparticles have wide size range from 5 nm to 500 nm. Surface functionalized titania particles are also available for covalent conjugation with proteins, antibodies and other biomolecules. These titania nanoparticles can have broad applications in skin products, additives, foods, air cleaning due to its strong UV absorption and active photocatalytic properties.

1. Shi, H., Magaye, R., Castranova, V., & Zhao, J. (2013). Titanium dioxide nanoparticles: a review of current toxicological data. Particle and fibre toxicology, 10(1), 1-33.
2. Sanches, P. L., Geaquinto, L. R. D. O., Cruz, R., Schuck, D. C., Lorencini, M., Granjeiro, J. M., & Ribeiro, A. R. L. (2020). Toxicity evaluation of TiO2 nanoparticles on the 3D skin model: a systematic review. Frontiers in Bioengineering and Biotechnology, 8, 575.
3. Nyamukamba, P., Okoh, O., Mungondori, H., Taziwa, R., & Zinya, S. (2018). Synthetic methods for titanium dioxide nanoparticles: a review. Titanium Dioxide—Material for a Sustainable Environment; Yang, D., Ed, 151-175.
4. Tsuchiya, H., & Schmuki, P. (2020). Less known facts and findings about TiO 2 nanotubes. Nanoscale, 12(15), 8119-8132.
5. Waghmode, M. S., Gunjal, A. B., Mulla, J. A., Patil, N. N., & Nawani, N. N. (2019). Studies on the titanium dioxide nanoparticles: Biosynthesis, applications and remediation. SN Applied Sciences, 1(4), 1-9.

Author's Bio: 

CD Bioparticles provides fluorescent carbon quantum dots (C-dots) with high quality and quantum yield and wide applications such as imaging, biosensor, drug delivery, optronics, and catalysis. AS a leading supplier of nanoparticles, CD Bioparticles offers high quality carbon nanomaterials including carbon nanotubes, nanofibers, carbon quantum dots, and graphene. Our carbon nanotube products include single-walled, double-walled and multi-walled structures with different sizes and surface modifications.