RESUMO
TiO2 pillared montmorillonite composite photocatalyst was synthesized by acid-catalyzed sol method and characterized by IR, UV-Vis, TG/DTA, XRD, SEM etc. Spectral analyses have demonstrated that TiO2 pillared montmorillonite(Ti-MMT) has wider interlayer distance than Na substituted montmorillonite (Na-MMT) and higher optical absorption efficiency than nanoscale anatase TiO2. The photocatalytic degradation reaction of acidic fuchsine by sunlight was employed to evaluate the catalytic activity of the composite catalyst. It was found that, besides easy reclaimation, the photocatalytic activity of the catalyst was much higher than that of the pure nanosized anatase TiO2. When the addition amount of Ti-MMT is 0.2 g x (100 mL)(-1) and pH of acidic fuchsine solution is 3, the dye could be degraded thoroughly in 40 min and the degradation reaction obeys Langmuir- Hinshelwood equation.
RESUMO
In the paper, undoped and Pr2O3 doped TiO2 nanoparticles were prepared by a sol-gel process using Ti(OC4H9)4 as raw material and characterized by means of XRD TG-DTA, AFM, UV-Vis and FTIR. The photocatalytic activity of Pr2O3/TiO2 was evaluated by the photocatalytic degradation of acidic fuchsine. The factors affecting on photocatalytic activity of Pr2O3/TiO2, such as the content of doped Pr2O3, the calcined temperature and added amount of the catalyst etc. were discussed. It was shown that Pr doping hampers the transformation of TiO2 crystal phase from anatase to rutile, and with Pr2O3 doping the particle diameter of Pr2O3/TiO2 samples decreased, the specific surface area increased and the photocatalytic activity improved. When doping amount of Pr is 0.8%, added amount of the catalyst is 0.03 g and the calcination temperature is 500 degrees C, the degradation efficiency of acidic fuchsine reaches 97%. The photocatalytic degradation of acidic fuchsine by Pr2O3/TiO2 is a quasi-first order dynamic reaction.
