Synthesis And Properties Of Pure Phase Magnesium Titanate Nanocrystals And Their Composites

Perovskite nanomaterials have important applications in the field of photocatalytic hydrogen production.With the study of photocatalytic hydrogen production materials,the properties of photocatalytic hydrogen production are limited by the properties of nano materials.Titanate is a good photocatalyst.In particular,magnesium titanate exhibits higher photocatalytic hydrogen production activity,but it is difficult to synthesize pure magnesium titanate.Therefore,it is of great significance to synthesize pure phase nanocrystals for photocatalytic reaction.This paper describes the synthesis of pure phase MgTi2O5,Mg1.2Ti1.8O5 and MgTiO3 nanocrystals for the first time,which were applied to the field of photocatalytic hydrogen production.And we have synthesized the C3N4/Mg1.2Ti1.8O5 composites.The main contents in this thesis are as follows:(1)In the process of synthesis of Magnesium titanate nanocrystals,it is easy to produce impurities and the mixed phase structure appears.In this paper,we successfully synthesized pure phase MgTi2O5 nanocrystals via a facile organic ligand coordinated polymeri-zation method.Pure phase MgTi2O5 nanocrystals are synthesized by controlling the reaction temperature and concentration.The structure and morphology of the products were analyzed by XRD,SEM,TEM and EDS.In this paper,the structure and morphology of the product was analyzed by XRD,SEM,TEM,EDS and other methods.The results of PEC analysis showed that the MgTi2O5 nanocrystals have better charge separation effect,larger charge density and smaller electrochemical impedance in the photocatalytic reaction.(2)We successfully synthesized pure phase Mg1.2Ti1.8O5 and MgTiO3 nanocrystals using a hydro-thermal method.The pure phase Mg1.2Ti1.8O5 and MgTiO3 nanocrystals were obtained by changing the solvent and the reaction concentration.The structure and morphology of pure phase Mg1.2Ti1.8O5 and MgTiO3 nanocrystals are different.The results of photocatalytic hydrogen production showed that the photocatalytic activity of Mg1.2T1.8O5 nanocrystals was good.The PEC analysis showed that the Mg1.2Ti1.8O5 has better charge separation effect,larger charge density and smaller electrochemical impedance in the photocatalytic reaction.(3)The C3N4/Mg1.2Ti1.8O5 composite nanocrystal with composite ratio of 1:0.2 were successfully synthesized by combining pure phase Mg1.2Ti1.8O5 with C3N4,and the structure and morphology of the composite were investigated.In addition,the photocatalytic hydrogen production performance of the sample was studied.