Synthesis And Photocatalytic Properties Of The TiO₂ Loaded Nature Vemiculite

In recently, supported photocatalytic oxidation has become one of research focuses in this field because it is high photoactivity, regeneration and low-cost. The current work primarily investigates the preparation and photocatalytic property of TiO₂ loaded on vermiculite. The search contents and results were as follows:1. Optimum conditions in preparation the TiO₂/vermiculite photocatalyst. The TiO₂/vermiculite catalysts were characterized by XRD, SEM, TG-DTA, FTIR and BET. The photocatalytic activities were evaluated by using methyl orange as photodegradation target. The effect of the catalysts concentration, the concentration of methyl orange solution, the amount of TiO₂ loaded, the calcination temperature and different light on the photocatalytic efficiency has also been investigated. Also, the photodegradation of different dyes was investigated. The experiment results showed that 25% TiO₂/vermiculite catalyst calcined at 200oC shows higher photocatalytic efficiency. The discoloration rate of methyl orange solution reached 84.6% under UV light irradiation for 30min, and the kinetic of photocatalytic oxidation fits with the first-order kinetic model.2. The ion-doped TiO₂/vemiculite was synthesis by Sol-Gel method. The doping content has an optimal value. Doping certainty content Cr3+, Co²⁺, Ni²⁺ and Zn²⁺ can enhance the photocatalytic activity of TiO₂ obviously, doping Cu²⁺ have little influence on the photocatalytic activity of TiO₂, while doping Mn²⁺ decreases the photocatalytic activity.3. TiO₂ loaded on zeolite 4A and vermiculite were synthesized by sol-gel technique. This paper primarily studies the effects of different supports of zeolite 4A and vermiculite on photocatalytic activity, and also investigates the adsorption law and the photocatalytic oxidation process of methyl orange on composites. The results indicate that the adsorption law of methyl orange on composites fit very well with the Langmuir model and Freundlich model, and the adsorption property. The supports can affect the photocatalytic activity. With 20 mg/L of methyl orange solution concentration under UV light irradiation for 30min, the discoloration rate of methyl orange reached 84.6% on TiO₂/Vermiculite and 78.5% on TiO₂/Zeolite 4A, respectively, higher than that of bare TiO₂ (68%) prepared by sol-gel technique in same experimental condition.