The particulate hydrous oxides of rare-earth RExOy· nH2O(RE=Ce,Nd,La,Pr)have been prepared using polyacrylonitrile as adhesive agent. They showed better fluorideremoving property. The adsorption mechanism in relation with the pH value and temperatureof the solution have been discussed briefly.
The TiO 2/SiO 2 coating particles have been prepared by a sol gel method with Ti(OC 4H 9) 4 and SiO 2 as precursors. The IR results indicate the existence of Si—O—Ti bonds on the catalyst. The crystalline phase of coating thin films(TiO 2) was studied by XRD. The amount of TiO 2 bound to the SiO 2 was determined by spectrophotometry. The TiO 2/SiO 2 can be used repeatedly and shows a higher photocatalytic decomposition rate for dichlorvos than TiO 2.
