Preparation Of Modified Titanium Dioxide Photocatalyst And Its Degradation Properties For Dibutyl Phthalate

In recent years,the problem of industrial waste water pollution has become more and more serious,and the organic pollution in wastewater is more prominent.Dibutyl phthalate(DBP),as an environmental toxin-type organic pollutant,can interfere with the endocrine system of the human body and is extremely harmful to the human body.DBP is now one of the carcinogens published by the World Health Organization’s International Agency for Research on Cancer.Photocatalytic technology is the use of light as an energy source to degrade various organic pollutants into water and carbon dioxide.It is an efficient and safe environment-friendly environmental purification technology.Some studies have shown that the use of modified titanium dioxide as a catalyst has a higher degradation activity on organic pollutants under light conditions.In this study,we mainly discuss the preparation and characterization of modified titanium dioxide and the photocatalytic degradation behavior of DBP.In this paper,hydrothermal synthesis method was firstly used,and various porous titanium dioxide(TiO2)particles were prepared by controling experimental conditions such as surfactant type,reaction concentration,calcination temperature and calcination time.The prepared sample degrades a certain concentration of DBP solution under the condition of xenon lamp.The optimal preparation conditions of the catalyst were summarized according to the degradation rate,and the catalyst was characterized by X-ray diffraction(XRD),Brunauer-Emmett-Teller(BET),Electron scanning microscopy(SEM),Fourier transform infrared(FT-IR)and Thermogravimetric analyses(TGA),.When the surfactant was selected from the group consisting of polyethylene glycol,water and tetrabutyl titanate in a molar ratio of 10:1,calcination temperature of 450℃ and calcination time of 4 h,the degradation efficiency of DBP solution was up to 44.7%.Secondly,magnetic porous TiO2/Ag composite photocatalyst with Fe3O4 was prepared using tetrabutyl titanate as a titanium source.The prepared samples were characterized by XRD,TGA,SEM,FT-IR and BET.Since the forbidden band width of TiO2 is too large to function well under visible light,we modify TiO2,and the added silver ions can reduce the forbidden band width of TiO2 and prevent electrons and holes from recombining.The prepared TiO2/Ag composite photocatalyst showed some activity on the degradation of DBP.The optimum degradation conditions were found by changing the light conditions,the initial concentration of DBP solution,the amount of hydrogen peroxide,the amount of magnetic TiO2/Ag,and the pH of the DBP solution.Using the fluorescent lamp as a light source,the degradation efficiency of DBP reached 74%when the concentration of DBP solution,the amount of catalyst,the amount of hydrogen peroxide,and the pH of DBP solution were 20 mg/L,0.02 g,30 μL,and 7,respectively.In addition,the magnetic composite photocatalyst was recycled,and reused for 5 times,the corresponding degradation rate did hardly change.Combined with the above experimental results,the possible mechanism of the degradation process was proposed.