Preparation And Photocatalytic Performance Research Of NaNo-TiO₂

Environmental pollution and destruction as well as the lack of sufficient clean and natural energy resources are some of the most serious problems presently faced on a global scale.The increase in world population and the rampant unregulated industrial growth have all led to accelerated energy consumption,while the unabated release of toxic agents and industrial waste into the air and water.It should therefore be our goal to contribute to the development of environmentally harmonious,ecologically clean and safe,sustainable,and energy efficient chemical technologies,the most urgent challenges scientists are facing today.Photocatalysis,in which the inexhaustibly abundant,clean,and safe energy of the sun can be harnessed for sustainable,nonhazardous,and economically viable technologies,is a major advance in this direction.The Ti（OH）₄ colloid is prepared from the hydrolysis reaction of the tetrabutyl titanate by sol-gel method.The nano Ag-TiO₂ photocatalytic materials were formed after drying,calcining and cleaning.Then,the optimum process parameters had been determined.The parameters included the titanium dioxide with different mixed amounts of Ag,calcining temperature and time.Utilize the best process parameters previously obtained the Ag/CTAB-TiO₂ by the template of CTAB.The samples were characterized by XRD,XPS,SEM,TEM,N₂adsorption-desorption,UV-vis and electrochemical workstation.The photocatalytic properties of the products were estimated by the photodegradation of methylene blue under visible light irradiation.The main research results are as follows:（1）when the calcination temperature is 500℃,the calcination time is 3h,the doped amount of silver ion is 5at%,the amount of CTAB is 1at%we can get the highest catalytic rate of Ag/CTAB-TiO₂.The photodegradation rate of Ag/CTAB-TiO₂ is 4 times than pure TiO₂.（2）Ag/CTAB-TiO₂ had anatase crystal phase,The dopant Ag existed as Ag^（0）.The photo-response of Ag/CTAB-TiO₂ was greatly shifted into the visible light spectrum.The CTAB can change the surface morphology of the composite,the sample surface was loose and porous,which can increase specific surface area and material S_BETET area is two times more than pure TiO₂.Under visible irradiation,photocurrents of Ag/CTAB-TiO₂ was much higher than that of the Ag-TiO₂ and pure TiO₂.The CTAB can change the surface morphology of the composite,the sample surface was loose and porous.（3）The regenerated photocatalyst is still stable after five cycling runs,and give more than 85%degradation.