Nano particles have many advantages as photocatalysts. Firstly, the particle size is small, the specific surface area is large, and the photocatalytic efficiency is high. In addition, most of the electrons and cavities generated by nanoparticles do not recombine until they reach the surface. Therefore, if more electrons and cavities can reach the surface, the chemical reaction activity will be high. Secondly, nano-particles dispersed in dielectrics are often transparent, which makes it easy to utilize optical means and methods to observe the effects of charge transfer, proton transfer, semiconductor energy level structure and surface state density at the interfaces. At present, the industrial use of nano titanium dioxide – ferric oxide as a photocatalyst for wastewater treatment (containing SO32- or Cr2O72-systems), has achieved very good results.
The white spherical zinc titanate powder with a particle size of about 30~60nm prepared by the precipitation dissolution method has a large specific surface area and high chemical activity, and the effect of using it as an adsorption desulfurization agent is significantly improved compared with that of the zinc titanate powder prepared by the solid-phase sintering method.
Nano ESD shielding material is another important application of nanotechnology. In the past, ESD shielding materials are generally made of resin doped with carbon black spray coating, but the performance is not particularly ideal. In order to improve the performance of static shielding materials, Japan’s Panasonic Corporation developed a good static shielding nanocoatings. The use of semiconductor properties of nanoparticles such as Fe2O3, TiO2, ZnO oxide particles made of coatings, due to the high conductivity characteristics, and therefore can play a role in electrostatic shielding. In addition, the oxide nanoparticles of various colors, so you can control the color of the electrostatic shielding coatings by laminating, this nano electrostatic shielding coatings not only have good electrostatic shielding properties, but also overcome the carbon black electrostatic shielding coatings only a single color monotony.
In addition, if nano-TiO2 powder is added to cosmetics in a certain proportion, it can effectively shield ultraviolet rays. It is generally believed that its system only needs to contain nano-TiO2 0.5~1%, can be fully shielded from ultraviolet rays. At present, Japan and other countries have part of the nano titanium dioxide cosmetics. UV rays can not only make meat food automatically oxidized and discolored, but also destroy the vitamins and aromatic compounds in food, thus reducing the nutritional value of food. Such as the addition of 0.1 ~ 0.5% of nano titanium dioxide made of transparent plastic packaging material packaging food, not only can prevent the ultraviolet rays on the destructive effect of food, but also can make the food to keep fresh. Metallic nanoparticles mixed into the chemical fiber system or paper, can greatly reduce the electrostatic effect. The use of nanoparticles constitute a sponge-like light sintered body, can be used for gas isotopes, mixed rare gases and organic compounds, such as separation and concentration, used in battery electrodes, chemical composition detector and as a high-efficiency heat exchange spacer materials. Nano particles can also be used as conductive coatings, printing inks and solid lubricants.
ZnCO3 coated Ti(OH)4 particles obtained by chemical co-sedimentation method, at a certain temperature after pre-roasting, dissolve most of the coated ZnO powder, the use of a small amount of ZnTiO3 in the system (ZnTiO3 and TiO2(R) crystal structure is similar) to promote the TiO2 from anatase to rutile transformation, the production of rutile titanium dioxide particles with a particle size of about 20 ~ 60nm. The powder was produced with a particle size of about 20~60 nm. The optical properties were tested by ultraviolet spectrophotometer, and it was found that the powder had a strong absorption of ultraviolet rays from 240 to 400 nm, and the absorption rate was as high as 92%, which was much higher than that of ordinary TiO2 powder. In addition, due to the quantum size effect and volume effect of the nanopowder, the spectral properties of the nanoparticles show the phenomenon of “blue shift” or “red shift”. In the preparation of ultrafine aluminate-based long afterglow luminescent materials, the main peak position of the emission spectrum of the ultrafine luminescent powders synthesized by the soft chemistry method was shifted by 12 nm compared with that of the luminescent powders prepared by the solid-phase mechanical mixing and sintering method, and the afterglow decay curves indicated that the afterglow of the luminescent powders synthesized by this method decayed at a much faster speed compared with that of the luminescent powders synthesized by the solid-phase method, which was caused by the significant reduction of the powder particles. These are due to the large reduction of the powder particles.
The researchers also found that the unique pore-like structure of nanocarbon tubes, large specific surface (the surface area of each gram of nanocarbon tubes is up to several hundred square meters), and high mechanical strength can be utilized to make nano reactor, which is capable of restricting the chemical reaction to a very small area. In the nanoreactor, the reactants are oriented and ordered at the molecular level, but at the same time, the movement of the reactant molecules and reaction intermediates is restricted. This orientation, arrangement and confinement will affect and determine the direction and speed of the reaction. Scientists have used nano-scale molecular filters as reactors, and in the photosensitive oxidation of olefins, the substrate molecules are placed in the pore cavities of the reactors, and the sensitizers are in solution, so that only single-phase oxidized products are generated. Macrocyclic compounds with certain pore sizes can be synthesized by reacting metal-alcoholic compounds with carboxylic acids. Different “nanostructures” can be formed as nanoreactors by utilizing block and contact copolymers that form microphase separations.
