Research On Dispersibility And Photocatalytic Activity Of Nano-TiO₂ Solution

With the development of society and the advancement of science and technology,people's living standards are also growing.However,it has also brought a lot of environmental pollution problems.Compared with the visible outdoors pollution problems,indoor pollution problems are more easily overlooked.Toxic gases such as benzene and formaldehyde are the most common sources of indoor pollution.Long-term living in this environment is the most harmful to the human body.In the treatment of indoor environmental pollution,titanium dioxide photocatalytic degradation of pollutants has gradually attracted people's attention.However,the nanometer titanium dioxide has a large specific surface area,and is highly prone to agglomeration,and the nano powder has the disadvantage of being inconvenient to use.In view of the above problems,the nanometer titanium dioxide powder with good photocatalytic performance is made into a stable dispersion spray and its practical application is the focus of this paper.Firstly,nano-titanium dioxide powder with good photocatalytic performance was prepared by hydrothermal method and nitrogen-doping treatment,and then a series of stable dispersion was carried out.The main conclusions of this paper are as follows:?1?In terms of physical dispersion,the dispersion mode and dispersion time are changed.According to the dispersibility characterization,the ultrasonic dispersion effect is better than the magnetic stirring,and too short or too long ultrasonic time is not conducive to dispersion.The optimal ultrasonic time is about 20min.Through the regulation of pH value,it was found that nano titanium dioxide had the worst dispersion effect near the isoelectric point?pH=4.4?.?2?Since physical dispersion cannot be stabilized for a long period of time,considering chemical dispersion,three kinds of dispersing agents with the best dispersing effect are selected by screening various dispersing agents,and the mass ratio of the dispersing agent and the pH value are adjusted.The optimum conditions for use of each dispersant were obtained:0.03%Dispersant A,0.07%Dispersant B and 0.1%Dispersant C,and the pH was adjusted to 9-10.The dispersion effects of the three dispersants were compared:B>A>C.?3?The photocatalytic performance of the three dispersions with the best dispersion was tested.It was found that the nano-titanium dioxide after the addition of the dispersant had poor photocatalytic performance,which was far less than the undispersant powdered titanium dioxide.Through analysis and characterization,it was found that the surface of nano-titanium dioxide adsorbed many groups of dispersant,which may be the reason that affects the photocatalytic performance.The effects of practical application conditions such as load and light source on photocatalytic performance were investigated.The photocatalytic effects of three kinds of dispersions on benzene degradation were C,B and A.For the comprehensive dispersibility and photocatalytic activity,the TiO₂ solution of Dispersant B was selected as the final spray product..This paper mainly introduces the dispersion of nanometer titanium dioxide,and applies the prepared dispersion to photocatalytic degradation of benzene.Although the stability and photocatalytic properties of the dispersion need to be improved,the spray has a very good development prospect in purifying indoor air.