合成Fe3O4@TiO2核壳结构磁性复合材料用于高效率吸收铀讲解.ppt

Synthesis of Fe3O4@TiO2 core–shell magnetic composites for highly efficient sorption of uranium (VI) 一、Experiment 1、Preparation of samples （1）Preparation of Fe3O4 particles 2.6g of FeCl3·6H2O,1.0g sodium citrate,4.0g of CH3COONa were dissolved in 80mL of ethylene glycol under vigorous stirring. Subsequently, the mixture was transferred to an autoclave and heated at 200?C for 10h. The resulting Fe3O4 particles were washed several times with ethanol and dried in a vacuum at 80?C for 12h. （2）Preparation of Fe3O4@TiO2 particles 6.8mL of titanium isopropoxide, 9.6mL of glacial acetic acid were dissolved in 60mL of ethyl alcohol. Then,0.4 g Fe3O4 particles were added to the mixture with ultra-sonic dispersion for 15 min. Moreover, 2.4g of polyethylene glycol and 3.6g urea were added to the above solution with vigorous stirring for 1h. Subsequently, the mixture was transferred to an autoclave and heated at 180?C for 8h. The resulting magnetic particles were washed several times with ethanol and dried in a vacuum at 80?C for 12h. 2、Characterization 3、Adsorption experiments 0.05g of Fe3O4@TiO2 particle was mixed with 50mL of UO2 (NO3)2·6H2O solution. After the adsorption processes, the samples were isolated from the supernatant by use of a magnet, and the supernatant solutions were analyzed with WGJ–III Trace Uranium Analyzer to obtain the concentrations ofuranium (VI) in solution. The solution pH was adjusted by adding 0.5M HNO3 and NaOH. The amount of uranium (VI) adsorbed per unit mass of the adsorbent was calculated according to Eqs. (1) and (2): Qe =(C0?Ce)V/m (1) Removal(%)=100(C0?Ce)/C0 (2) 4、Desorption studies To investigate the reusability of Fe3O4@TiO2 , 0.05g of Fe3O4@TiO2 was first put in contact with 50mL uranium (VI) for 240 min. After adsorption, desorption was carried out by washing the adsorbents with distilled water several times, and then the solution containing 50mL of HCl solutions with different concentrations was added i