Studies Of The Adsorption And Catalytic Performance Of Hollow LDO

As an important inorganic laminates,layered double hydroxides(LDH)has attracted much attention in recent years.Because of its unique layered structure,simple green synthesis method,excellent physical and chemical properties,it has been used in medicine,environmental and other fields.The hydrothermal calcination product composite metal oxide(LDO)has the advantages of large specific surface area,high stability and adjustable structure.By changing the charge density of the precursor layers and the template directive method,LDO with higher activity can be obtained.In this study,LDO with hollow spherical structure was prepared by template directive method.The effect of hollow spherical LDO on the adsorption behavior of pollutants in the environment and the signal response signal of acetone catalyzed luminescence system was studied by changing structure and profile of mixed metal oxide.The main research achivements are as follows:(1)Preparation of LDH@C precursor by hydrothermal attraction with hydrotalcite as raw material and carbon ball as template,and then calcination at high temperature to obtain hollow spherical composite metal oxide LDO.As an adsorbent,methyl blue was used as an example to be evaluated in the adsorption efficiency of anionic dyes by studying the model molecules.The results show that hollow spherical LDO exhibits higher adsorption capacity(523.1mg/g)for methyl blue compared with the normal LDO without changing morphology,and the adsorption behavior conforms to Langmuir adsorption isotherm and quasi-second order kinetic model.The results of the adsorption mechanism show that the reason is that the hollow spherical LDO has a larger specific surface area,which can adsorb methyl blue in the water by electrostatic attraction,and can form hydrogen bonds with the mixed metal oxide.Thus,changing the morphology of the LDO can more effectively remove the anionic contaminants in the environment.(2)The hollow spherical LDO and the normal LDO were applied in the acetone-oxygen catalytic luminescence system,and the performance of the sensors was compared.As the experimental results shown,under the optimum reaction conditions,the hollow spherical LDO signal intensity is three times that of the normal LDO signal.The standard curve of the acetonitrile solution is measured in the range of 0.1-20mM,and the regression equation is △I=98.527X +96.94(R2=0.9602),where △I and C are the relative catalytic luminescence signal and the acetone solution concentration.In addition,compared to normal LDO,hollow spherical LDO as a catalyst in the synthesis process is simple,non-toxic,no complicated steps before sampling.It can increase the signal strength,with fast response,easy operation,low cost.As a catalyst,of its the excellent advantages,hollow spherical LDO has high sensitivity.