| In recent years, With the development of society and the awareness of the environmental protection, nano-semiconductor photocatalytic material attracts lots of the scientists in every fields.This photocatalytic material has been the hottest research area for its high specific surface area, high surface density of lattice defects and high specificsurface energy. However, there are two limited factors for the photocatalyst to overcome: the first one is the low photocatalytic quantum efficiency, the second one is the low utilization rate of solar. At present, the solved methods have been employed are ion-doping, semiconductor coupling, dye sensitization, etc. In this paper we choose the localized surface plasmon resonance(LSPR) characteristics of noble metal nanoparticles as the breakthrough to enlarge the utilization rate of visible light and the photocatalytic efficiency. It has been demonstrated that LSPR can expand the absorded light wavelength from UV to visible light, and decrease the recombination rate of photogenerated electrons and holes.We select Ti O2 as the semiconductor photocatalyst for its high efficiency, no toxicity, good stability and low cost, and Au nanoparticles of high activity as the noble loaded particles. Besides, the traditional Ti O2 photocatalyst powder is difficult to separate and recycle, so we take the type of Ti O2 film. In addition, high specific surface area is beneficial for Ti O2 contacting with Au nanoparticles fully and absorbing solar. In the study, in order to increase the specific surface area, a layer of Ti O2 seed is coated on bare glass by sol-gel and dip-coating. Subsequently another layer of nanosheet Ti O2 is growing on the seed by hydrothermal method. This nano structure not only has photocatalysis, also has certain antireflective effect. The main experiments are as follows:Firstly, we dip-coated a layer of amorphous Ti O2 from Ti O2 sol-gel precursor on the bare glass substrates, which were ultrasonically cleaned with deionized water, ethanol, acetone and isopropanol, at speed of 20 mm/min. Ti O2 sol-gel precursor was prepared by stirring the mixture of 30 m L isopropanol, 1.2 m L hydrochloric acid and 2.04 g tetrabutyl orthotitanate over 30 minutes. The amorphous Ti O2 was transferred into Ti O2 nanocrystal seeds layer by thermal-treating the pre-coated glass in an electric oven at 450℃for 4h. Next, after 15 min plasma surface treatment, the glass with Ti O2 seed layer was placed into a Teflon lined stainless steel autoclave, which contained 30 μL DETA, 30 m L isopropanol and a variable amount of Titanium(IV) isopropoxide. The sealed autoclave was heated to 180℃for 18 h in an electric oven. Then, the reaction was naturally cooled to room temperature. The as-prepared samples were gently rinsed with ethanol and dried at room temperature. Finally, the samples were annealed at 400℃for 1h to form the crystal. Then we carry out the characterization of the nanosheet Ti O2 film, such as structural and elemental chemical composition, crystallographic analyses and morphology, etc.Besides, we synthesised Ti O2 microsphere and Ti O2 microsphere loaded with Au nanoparticles. And simple contrastive degradation experiment between Ti O2 microsphere and Au-Ti O2 microsphere was took to determine Au nanoparticles loaded.In the paper the nanosheet Ti O2 film made has good hydrophilic and antireflection effect in the visible band when we study solar enhanced plasmonic materials. What’ more, the film can degrade Rhodamine B chloride well. The nanosheet Ti O2 film can be applied in self-cleaning and microfluidic water treatment, etc. In another hand, the Au-Ti O2 microsphere can be fixed in a microfluidic reactor for its good photocatalysis, also can be used in water treatment. |
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