Titanium dioxide is a Titanium(IV) oxide compounds.According to its physical structure, Titanium dioxide can be divided into rutile, anatase; crystal system tetragonal. Titanium dioxide used for photocatalyst, cosmetics, and can rely on UV disinfection and sterilization, are being widely developed, and have the opportunity to become a new industrial future.
Global energy is becoming less and less, and environmental pollution is to take advantage of the green and environmentally friendly energy to deal with the increasingly serious environmental pollution has become a serious problem that we must face in the 21st century. sunlight is nature’s most common light source, how to use it effectively ,to take full advantage of our handing of environmental issues, is a major trend of development in the future.
Photolysis of water into hydrogen
Hydrogen is an ideal fuel, so clean and unlimited water and solar preparation of hydrogen by the worldwide attention. Although larger than its wide band gap energy effectively inspire TiO2, although due to H2 in the the Titanium dioxidesurface generation has a lot of potential, so pure Titanium dioxidecan not photolysis of water into hydrogen. In order to solve this problem, design a variety of experimental conditions, such as (a) pressure to Ti electrode bias (>0.25v), this system is like an electrochemical reactor effectively separate the photo-generated electrons and holes; (b) depositing a metal particles (especially the precious metals such as Pt, Au, Pd, Ag, etc.) on the surface of TiO2 , reducing the overvoltage generated by the gas on the catalyst surface.
Photoelectric conversion solar cells
using semiconductor sunlight into electrical energy which can be transmitted and stored, is one of the hottest semiconductor photocatalysts directions,especially the dye-sensitized solar cell. Sunlight is able to excite electronic from Titanium dioxidevalance band to the conduction band, can generate light voltage, when the closed circuit is formed with an external circuit, thus, the photocurrent is generated.
Organics photocatalytic synthesis
The conversion of organic matter by oxidation-reduction reaction is achieved, may use optical excitation Titanium dioxideband electrons and valence band holes to be realized.However, the Titanium dioxidephotocatalytic reaction often involves the highly reactive free radicals which do not have selective, because of its reaction selectivity is not high, made its application in organic synthesis limited.
Photocatalytic degradation of pollutants
Now, with the acceleration of industrialization and urbanization, the global confronted with serious water shortages, pollution Water Pollution reduce water use, exacerbated water shortages.Currently, the use of non-toxic, fast response and efficient degradation, no secondary pollution nano-Titanium dioxide photocatalytic method for treatment of sewage. Dye wastewater, wastewater, surface active agent, Freon, oily waste water, waste water containing heavy metals and so on can be degradation by nano-Titanium dioxide oxidative. The main advantages of this technology are: degradation is not selective, almost any degradation of organic matter; fast response, organic pollutants can be completely degraded into carbon dioxide and water in a short period of time;low energy consumption, mild reaction conditions; no secondary pollution.