Synthesis And Photocatalytic Performance Optimization Of Titanium Pillared Montmorillonite

Titanium pillared montmorillonite (TiO₂-PILM) with large basal spacing and specific surface area is a kind of novel nanocomposite with layered silicates. TiO₂-PILM which has TiO₂ of nanometer dimension as pillars between silicate layers, would be one of the suitable materials for degradation of toxic organic compounds. This is not only because TiO₂-PILM has photocatalytic activity, but also has large specific area in which the organic compounds can be absorbed and enriched, which overcomes the disadvantages of nano-TiO₂. The preparation of TiO₂-PILM by partial hydrolysis of TiCl4 in HCl is affected by many factors and researches been carried out reached different conclusions. The influences of various factors on the preparation of TiO₂-PILM by partial hydrolysis of TiCl4 have been studied systematically in our group. The prepared TiO₂-PILM has been used for the photocatalytic degradation of Methylene Blue and phenol. In this paper, TiO₂-PILM was prepared by sol-gel and partial hydrolysis of TiCl4 method, doping with iron to enhance the photocatalytic performance of TiO₂-PILM. The influences of the aging temperature and aging time of cross-linking agent on the structure of Ti-PILM in sol-gel method were studied. When the synthesis was carried out using a molar ratio HCl/Ti=2, [HCl] =6mol/L, Ti/Mt=10mmol/g, an aqueous suspension of 1% of montmorillonite, a homogenous pillared sample was obtained at room temperature. Co-pillaring, i.e., the use of the pillaring agent containing iron ions, was adopted in the preparation of Fe doped TiO₂-PILM by partial hydrolysis of TiCl4. Ti-PILM doped with 0.1%,0.2%,0.3%,0.4%,0.5% and 0.7% Fe were prepared under the optimized conditions and characterized by nitrogen adsorption/desorption, chemistry analysis, XRD and TGA-DAT. TiO₂-PILM doped with 1%Fe was used to photocatalytically degrade Methylene blue (MB) .The effects of the dosage of Fe doped TiO₂-PILM, initial concentration of MB and initial pH value on the efficiency of photocatalytic degradation were studied. Results show that TiO₂-PILM, when doped with Fe, is more efficient in the adsorption for MB and less efficient in the photocatalytic degradation of MB, which needs further study.