Preparation, Characterization And Application Of Modified Ldhs Compound Photocatalyst

Using co-precipitation synthesis LDHs-CeO₂photocatalysts and the synthesis conditions ofthe LDHs-CeO₂photocatalyst were studied. Synthesis results show that: LDHs-CeO₂photocatalyst process conditions were nMg:nAl:nCe=2:1:0.5, the calcination temperature400℃,calcinations time4h. Use of modern instrumental analysis methods: IR, XRD, SEM, TEM,EDS, TG-DTG and N2adsorption-desorption method for synthesis of photocatalyst laminatestructure, crystal structure and morphology, thermal stability and pore structure werecharacterized. Characterization results, LDHs-CeO₂photocatalyst is hexagonal, morphologyof the rules sheet structure, the photocatalysts show better dispersion, a highly crystallinephase and correspond to hexagonal system. The LDHs-CeO₂photocatalyst was used indegradation of Methyl Orange and Rhodamine B photocatalytic reaction.The conditions ofphotocatalytic reaction such as the initial concentration of dye solution, reaction time, pHvalue, amount of photocatalysts were studied.The optimum photocatalytic reaction conditionswere that the initial concentration of methyl orange solution was40mg/L, the pH=5, amountof catalyst was0.3g, dark standing20min and irradiation time60min. The degradation rateof methyl orange can reach98.69%under the optimum conditions.The optimumphotocatalytic reaction conditions were that the initial concentration of Rhodamine B solutionwas40mg/L, the pH=3, amount of catalyst was0.3g, dark standing20min and irradiationtime60min. The degradation rate of Rhodamine B can reach90.45%under the optimumconditions.The use of tetraethoxysilane （TEOS） as silicon source was prepared by suspension of silicamicrospheres and as a template using the template synthesis LDHs-CeO₂/SiO₂photocatalyst.Experimental studies have shown that: LDHs-CeO₂/SiO₂photocatalyst process conditionswere the calcination temperature500℃, calcinations time4h. Use of modern instrumentalanalysis methods were characterized. Characterization results, LDHs-CeO₂/SiO₂photocatalyst for the complete spherical morphology, the photocatalysts show betterdispersion, a highly crystalline phase and correspond to hexagonal system. The optimumLDHs-CeO₂/SiO₂photocatalytic reaction conditions were that the initial concentration ofmethyl orange solution was80mg/L, the pH=5, amount of catalyst was0.3g, dark standing20min and irradiation time60min. The degradation rate of methyl orange can reach93.75%under the optimum conditions.The optimum photocatalytic reaction conditions were that the initial concentration of Rhodamine B solution was40mg/L, the pH=3, amount of catalystwas0.3g, dark standing20min and irradiation time60min. The degradation rate ofRhodamine B can reach94.29%under the optimum conditions.The results showed that both photocatalytic degradation of Methyl Orange and RhodamineB have better performance, and photocatalytic degradation of two dyes belong to be a reactionkinetics, in line with Langumuir-Hinshelwood model. The prepared photocatalysts have goodphotocatalytic degradation properties, and the photocatalysts have good reusability.