Preparation of organic montmorillonite supported TiO2 and its application in methylene blue removal

• The basal spacing of Mt was 4.35 nm by using 1.5 STAB. • TiO 2 loading was increased from 10.2% in Mt/TiO 2 to 46.7% in OMt/TiO 2 . • Replacing Mt by OMt, the pore volume of TiO 2 was enhanced by 69%. • Band gap and hole-electron pairs recombination of TiO 2 were reduced by OMt. High agglomeration and low adsorption limited the photocatalytic efficiency of TiO 2 . Hereupon, organic montmorillonite (OMt) was used as the support to load TiO 2 , with a view to achieve the homogeneous dispersion of nanoparticles and obtain the photocatalyst with mesoporous structure. In the present study, three kinds of expanding agents were used to prepare OMt, and then OMt/TiO 2 was produced by the process of diffusion, hydrolysis, and calcination. The microscopic properties were researched and the removal capability for methylene blue (MB) under simulated UV was discussed. Results showed that with the use of expanding agents, the basal spacing of montmorillonite (Mt) was enlarged significantly, and the biggest value was up to 4.35 nm. The optimal photoactivity of OMt/TiO 2 was observed after calcinating at 600 °C, which was much higher than that of Mt/TiO 2 and single TiO 2 . On the one hand, in comparison with Mt/TiO 2 , TiO 2 content in OMt/TiO 2 was increased by more than 358%, and the increase ratio for pore volume was 69%. On the other hand, in comparison with single TiO 2 , the mesoporous structure of OMt/TiO 2 improved the adsorption capacity for MB. Moreover, the surface of charge separation efficiency of TiO 2 was promoted by the presence of OMt, accelerating the photocatalytic removal of MB. Hence, the combination of OMt and TiO 2 could efficiently enhance photoactivity.