Different Morphology Of Micro / Nano Cerium Oxide, Preparation And Photocatalytic Performance

As a very important and wide used rare earth oxides, the cerium oxide has a widely application in the area of polishing, catalysis, ultraviolet absorbers, luminous materials and so on, Specific morphology of cerium oxide micro/nano materials, also have their own special characteristics, so the properties of surface area, UV absorption properties and surface adsorption all have their own respective special characteristics.This article discussed that we using the hydrothermal method by urea hydrolysis, prepared the shuttle-like, flower-like and spherical morphology of cerium oxide, we also develop a novel self-template way to get the hollow spherical cerium oxide by using sodium citrate and citric acid as the morphology control agent. And the products we get are characterized there phase, morphology, Structure, size, optical and photocatalytic by the following instruments:X-ray powder diffraction (XRD), Scanning Electron Microscopy (SEM), Field emission scanning electron microscope(FESEM), Ultraviolet-visible spectrometer(UV-VIS), Thermo Gravimetric Analyzer and differential scanning calorimeter(TG/DSC)1. Use cerium nitrate, citric acid, sodium and urea as raw materials in aqueous solutions, prepared shuttle-like and flower- like micro/nano cerium oxide, and discuss the cerium hydrocarbonate precursor's crystal growth process and mechanism. The optimal conditions of two different morphologies are as following:Urea and cerium nitrate molar ratio is 2:1, reaction temperature is 120℃, shuttle-like and flower-like's reaction time is respectively 24h and 48h.2. We also use hydrothermal method, but replace the sodium citrate with citric acid, can get the spherical morphology of cerium hydrocarbonate precursor and cerium oxide. And using self-template method, let the cerium hydrocarbonate precursor incompletely calcination, then using hydrochloric acid erode the cerium hydrocarbonate precursor inside, so as to prepare the hollow spherical cerium oxide. Adjusting the reaction temperature, time, first and final calcination temperature to optimize the reaction conditions, hollow spherical cerium oxide is getted.3. Considering cerium ions' variable adicity and oxygen storage properties, we use self-made device to perform photocatalytic degradation of the methyl orange solution. And discussing the different morphology cerium oxide like shuttle-like, flower-like, spherical and hollow spherical morphology of cerium oxide's photocatalytic degradation property, Under the irradiation of 60W tungsten-iodine lamp, cerium oxide's decolorization performance is depends on the size and the surface area, smaller particle size, the greater the specific surface area, marking the better decolorization performance..