The Preparation And The Measurement Of Performance Of TiO₂ Hollow Spheres With Mesorporosity

Spray drying is an environmental friend approach to prepare hollow spheres with quite low energy cost.The hollow sphere with nanostructure owns a high specific surface area and a special mesoporous structure.These characteristics enable it to be used as a kind of photocatalytic materials with a good prospect,as well as adsorbent materials and slow-release materials.In this paper,TiCl₄ sol was used as the precursor to fabricate mesoporous hollow spherical TiO₂ by spray drying.The morphology,crystal phase and microstructure of the sample were characterized by scanning electron microscope?SEM?,energy dispersive spectrometer?EDS?,X-ray diffraction?XRD?,physical adsorption analyzer and laser particle size analyzer.The effect of the concentration of the precursor,the inlet temperature of the liquid of the precursor,the flow of the precursor liquid and the calcination temperature on the morphology of the sample was investigated.The photocatalytic property,adsorption ability and slow-release performance of the samples were also tested in this paper.The main conclusions are as follows:1.The precursor concentration,inlet temperature,material flow and calcination temperature have a great impact on the morphology of the sample.And the optimal conditions are:the concentration of titanium tetrachloride is 0.1 mol/L;the inlet temperature is 220?;the flow of the precursor liquid is 1200 mL/h,and the calcination temperature of the sample is 470?.2.The average diameter of the hollow sphere with nanostructure and mesoporosity prepared under the optimal conditions is 0.990?m;the mean pore size is 26.1 nm;the specific surface area of the sample is about 30.8m²/g,and the crystal phase of the sample is composed of rutile only.3.Methyl orange was used as the degradation reactant to investigate the photocatalytic property of TiO₂.The results show that:titanium dioxide and hydrogen peroxide have a good synergy on the degradation of methyl orange solution.When the calcination temperature of the sample is470?,the photocatalytic performance of the sample is better than P25.4.Toluene,formaldehyde and acetone were used to study the adsorption ability of the sample.The results show that the adsorption efficiency of toluene,formaldehyde and acetone are 53.4%,110.0%,131.2%respectively.5.Citronellol was used as release agent to investigate the slow release capabilities.The results show that the load capacity of citronellol is about81.7%,and after 15 days,the content of citronellol sustained release device remains at 0.005 mg/mL or more.The results show that:in the optimized conditions,the titanium dioxide prepared by spray drying method has a large specific surface area and a hollow spherical structure,which has a good photocatalytic property,adsorption ability and slow-release performance.