Preparation Of Ba_xSr_1-xTiO₃ Nanostructure And The Impact Of Ferroelectricity On Photocatalysis

Recently,perovskite-type nanostructures have received extensive attention due to their peculiar size effects and rich physicochemical properties,and Perovskite-type nanostructures have great potential for application in ultra-high-density memories and catalysts.According to the theory of semiconductor photocatalysis,a tentative study on the photocatalysis of perovskite materials has been carried out and show the advantages in catalysis area because of its thermal stability,chemical stability and structural stability.At the same time,ferroelectric materials are considered to be favorable candidates for photocatalysts due to their spontaneous polarization,which can reduce the recombination of photogenerated electrons and photogenerated charges.Now,researchers have realized that perovskite-type ferroelectric materials have great advantages in photocatalysis.However,the effects of polarity in perovskite ferroelectric materials in the field of photocatalysis have not been systematically reported.Therefore,the subject investigate the influence of polarity on catalytic performance by Ba_x Sr_1-xTiO₃ as photocatalyst which is a nanocomposite series includeing ferroelectric nanocrystals.In this study,BaTiO₃ with a particle size of⁶0nm and a nearly cubic shape was synthesized by hydrothermal method and coprecipitation method.Through the result of Raman and XRD refinement analysis,the sample was successfully determined to be a tetragonal phase,and a series of Ba _x Sr_1-xTiO₃nanocomposites with different ruthenium ratios were obtained by the same synthesis method.Next,we investigated the effect of polarization on the photocatalytic activity of BaTiO₃ for the decolorization of methyl orange whose chromophoric species carry charges with opposite polarity to that of Rh B in aqueous solution,and found that the ferroelectricity had a negative effect.Therefore,A mechanism taking into account not only the charge separation but also the preferential adsorption of charged dye species in the aqueous solution on the polar surfaces of ferroelectric particles has been proposed to explain t he observed phenomenon.The results unravel the importance of polarity match between the chromophoric species of the dye in the aqueous solution and the photo-induced charge carriers responsible for the photocatalysis.In order to verify,BaTiO₃ nanoparticles without surfactant and SrTiO₃ nanoparticles with paraelectric phase as catalyst decolor MO to exclude the influence of the catalysts surface condition and the reaction environment.For further study,we conduct photodegradation experiment using Ba_x Sr_1-xTiO₃ of different enthalpy contents with diverse polarity intensity as catalyst.The results once again demonstrate the photocatalytiic reaction mechanism of the ferroelectricity.