Efficiency Analysis Of Nano-TiO₂ Photocatalytic Purification Of NO_x In Automobile Exhaust

With the development of economy of our country,the vehicle quantity of our country increases at the speed of 20%per year in recent years,therefore the demand for the fuel doubles and redoubles.The automobile exhaust by burning fuel becomes the primary pollution source of our country's urban air.In numerous kinds of vehicle emission,the quantity of NO_x is not only taller,but its harmfulness is heavier,so purification and control of NO_x seem to be very important.As to the vehicle itself,vehicle emissions can be reduced by two ways to some extent:in-engine purification and out-engine purification.But the degree of reduction is limited. In numerous new methods to control and purify automobile exhaust,nanometer TiO₂ photocatalyst technology becomes the study focus for its advantages,such as innocuity,low energy consumption and without secondary pollution.It makes the harmful substance absorbed on the surface degrade or decompose through the photo catalysis.It is a effective method to purify automobile exhaust in the atmosphere.So,if nanometer TiO₂ photocatalyst material could be adhered to the top layer of cement concrete,and make it to environmental protection cement concrete road surface material.Or this kind of material could be made to environmental protection dope and brushed on road facilities.Then automobile exhaust from the vent-pipe is changed into CO₂ that is harmless to human body.This will reduce the range and intensity of the automobile discharge exhaust greatly,thus the injury to people can be controlled.This material purifies the emissions as soon as the emissions exhaust.Its absorbing area is large, effect is good.It will become the key point of emissions purification research in the future.At present,the Northeast Forestry University has already loaded nanometer TiO₂ photocatalyst material on the white concrete road surface.But the white concrete road surface of load nanometer TiO₂ is under various influence factors(temperature,illumination and the like),the purification efficiency to the automobile exhaust has not studied clearly.This paper takes chemical reaction mechanism and photocatalyst principle of automobile exhaust as the theoretical foundation,and by utilizing nanometer TiO₂ photocatalyze physical simulation test system,white concrete road that loads nanometer TiO₂ photocatalyst material is tested many times.And the test data is screened and deal with to analyze the road surface under the influence factors,such as eroding,wearing and tearing at different illumination,tempera-ture,flushing.This provides better and more extensive application basis for its application on highway engineering.