The Producing Of Modified Nano-TiO₂ Thin Films And Photocatalytic Treatment Wastewater Coking

With the excessive exploitation of natural resources and grave Pollution of environment,the deterioration of ecological environment becomes more and more serious.It is urgent to develop eco-materials,which use economically energy and have no harm to environment.With its renewal ability and storability of energy and friendliness of environment,nano-semieonductor TiO₂ is the very novel green purificant, Now its relevant study becomes the focus of the field of photocatalysis,especially in wastewater treatment.Although nano-TiO₂ Powders can be obtained by many methods such as Sol-Gel Process,chemical deposition,these methods are complex in equipments,strict in conditions of preparation..As a result,it is difficult to realize its commercialization.The pertinent research work has been carried out follows.In environment protection field,it is one of key controlling objects to decontaminate wastewater coking,which poses great harm to environment and become a serious problem in metallurgy industry.Photocatalytic oxidation of water contaminants is a new method for wastewater treatment.It is widely and deeply studied by researchers for its high degradation efficiency,none secondary pollution caused and the potential of utilization of solar energy.Nano-titanium dioxide,used as a photocatalyst can degrade the trace organic compounds to non-toxic substances and can kill bacteria and virus,therefore,it is of great value in the practical applications. However,it suffered from the disadvantages that the nano-titanium dioxide cannot show the excellent photocatalytic activity until irradiated with UV light and the utilization of the solar rays is too limited and ineffective,which hinders its widespread applications to a great extent.In order to improve the photocatalytic activity and make full use of the solar rays,the nano-titanium dioxide must be modified. S-doped uniform TiO₂ photocatalysts were prepared using thiourea as the doping agent for the first time in China.The influence of sulfur doping on the crystal structure of nano-TiO₂,the energy level state and the surface state were investigated.The doping mechanism was also discussed.The results of photocatalytic degradation coking-plant wasterwater demonstrated that the S-doped uniform TiO₂ exhibited the highest photocatalytic activity when calcined at 450℃for 4 hours.The COD and NH₃-N are accord to water's quality.