The Synthsisi Of Ce-doped BaTiO₃ And It’s Enhancement Of Photocatalytic Property

With the rapid development of industry and agriculture,our water quality has been seriously polluted due to the emission of dyes,pesticides and other organic compounds,which adversely affects the ecological balance.Water pollution has become the key issues in modern society and the most urgent problems to be solved in daily life.Photocatalytic degradation of semiconductor materials is one of the effective ways to degrade organic pollutants because of its high efficiency,chemical stability,and without secondary pollution.Up to now,The photocatalytic materials currently studied mainly include TiO₂,ZnO,ZnS,CaTiO₃ and Ba TiO₃.Barium titanate is a typical perovskite type oxide with good ferroelectric,thermoelectric and piezoelectric properties.Due to the bending characteristics of ferroelectric materials,the photocatalytic performance can be improved by reducing the composite of charge carrier.The study object is BaTiO₃ particles.The highly Active titanate precursor are prepared by the first step of hydrothermal procedure.The wheat-shaped of barium titanate is acquired after the second step hydrothermal operation and the photocatalytic performance was studied;Finally,the preparation of BaTiO₃ photocatalyst is doped and modified by Ce.This paper is mainly aimed at the phase composition,crystal structure and morphology characteristics of BaTiO₃ by using XRD,SEM and TEM.Through the PL test and uv-vis diffuse reflectance to research the optical performance of the prepared samples.Adsorption and photocatalytic properties of the samples was studied by setting the methylene blue solution as the target objects.The main researching contents of this paper include:（1）A highly active titanate nanotubes were prepared by one-step hydrothermal method,preparation conditions is 10M NaOH and TiO₂ reacting under 180?C for 48 h.Then the adsorption properity of methylene blue solution was tested repetitively.Titanate nanotubes show strong adsorption performance to methylene blue solution and make its adsorption rate get over 90%within 5 min,4 times repeat tests are reached more than 90%within 5 min.（2）Using the first step hydrothermal preparation of the precursor of titanate as the reactant,the wheat shaped BaTiO₃ photocatalyst is prepared by the second step hydrothermal reaction by changing the reaction conditions such as temperature,time and concentration of mineralizer.We find out the best reaction conditions of preparation of BaTiO₃ is 1 M NaOH reacting at 200?C for6h.Under the preparation condition of the BaTiO₃,light photocatalytic performance of the catalyst is the optimum.The band width of BaTiO₃ photocatalyst prepared under the optimum reaction conditions is around 3.2eV.（3）No new phases are introduced at A-site Ce³⁺doped BaTiO₃ through XRD testing,that means the modified BaTiO₃ photocatalyst has the same structure as the pure phase BaTiO₃.To compare with TEM,it is a certain change in wheat-shaped of samples,i.e.,the wheat-shaped of BaTiO₃particles gradually change into a bar and small granular structure,at the same time,particles size get smaller.Uv-vis diffuse reflectance test analysis find that Ce³⁺ion doping at A-site can make BaTiO₃ photocatalyst width of the forbidden band is slightly reduced,therefore the way of A-site doping Ce³⁺ion less improve to properties of photocatalysis.By comparing with different concentrations Ce³⁺doped sample,we found that when the doping amount of Ce³⁺is 0.01 M,its photocatalytic properties of the pure BaTiO₃ is up to the optimum condition.（4）No new phases are introduced at B-site Ce⁴⁺-doped BaTiO₃ has the same structure and morphology as the pure phase,namely:XRD and TEM test find that Ce⁴⁺ionic doping do not introduce new hybrid phase and do not change the morphology.It was found that B-site Ce⁴⁺doping was significantly reduced the band gap width of BaTiO₃ photocatalysis and improved the photocatalytic performance of samples of Ba TiO₃.Comparing Ce⁴⁺doping,the photocatalytic performance of the BaTiO₃ was improved when the doping amount was 0.007 M.