Preparation And Property Of TiO₂ Nano-composites

TiO2 nanoparticles have excellent photocatalytic activity and can decompose the organic pollutants, such as hydrocarbon halogenate, phenol, acetone, and formaldehyde, to carbon dioxide and water. Therefore, TiO2 nanoparticles have wide applications in water purification and the elimination of air pollution. However, pure TiO2 nanoparticles have some shortages in application, since pure TiO2 can only absorb UV light due to their wide band gap, and cause secondary pollution due to their tiny power that is not easy to recycle use. Generally, TiO2 nanocomposits can overcome these disadvantages.In this paper, various TiO2 nanocomposites were prepared with titanium butoxide (TBOT) by water bath-ultrasound method. The products as-obtained were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Ultraviolet-visible Spectrophotometer (UV-vis). In addition, the photocatalytic activity and recycle of the TiO2 nanocomposites were discussed.Our main work as follows:1. The preparation of TiO2/Cu2O nanocomposite and its photocatalytic activityTiO2/Cu nanocomposite were prepared by ultrasound with water bathing. In preparation, tetrabutyl titanate (TBOT) was added into Cu(NO3)2 water solution. After ultrasounded for 60 min with water bathing, the mixture solution as-formed was reduced by hydrazine hydrate. By washing and drying at 80℃, the TiO2/Cu2O nanocomposite was obtained. The products were characterized by TEM and XRD. The results show that, in the nanocomposite, TiO2 is anatase and CU2O is cubic phase. In addition, the photocatalytic activity of the nanocomposite to MB was studied, and the effect factors, such as the time of ultrasound, quantity of Cu(NO3)2, was discussed.2. The preparation of TiO2/Fly Ash nanocomposite and its photocatalytic activityTetrabutyl titanate (TBOT) and Fly Ash were mixed in water, which was ultrasounded for 30 min with water bathing. By washing and drying at 80℃, the TiO2/Fly Ash nanocomposite was obtained. The products were characterized by SEM, XRD and UV-vis. The results show that, in the nanocomposite, TiO2 adhered to the surface of Fly Ash particles, which made the nanocomposite have high photocatalytic activity and easy to reuse.3. The preparation of Cu2O/TiO2/Fly Ash nanocomposite and its photocatalytic activityUnder ultrasonic condition, tetrabutyl titanate (TBOT) and Fly Ash were added into Cu(NO3)2 water solution. After ultrasounding for 30 min with water bathing, the mixture was reduced by hydrazine hydrate. By washing and drying at 80℃, the TiO2/Cu2O/Fly Ash nanocomposite was obtained. The products were characterized by SEM, XRD and UV-vis. The photocatalytic results show that, the photocatalytic activity of this trinary nanocomposite is higher than that of TiO2/Fly Ash nanocomposite. By investigating the influence of Cu(NO3)2 quantity in reaction solution on photocatalytic activity, the optimum component for the nanocomposite was obtained.