Several TiO₂ Array Nanostructure Thin Films Fabrication And Their Photocatalysis Properties

In this paper,first,briefly described the research significance and the present situation of semiconductor photocatalysis,described the photocatalytic mechanism of semiconductor photocatalysis,reviewed and analyzed the current progress and suffering problems about the TiO₂ and titanate nanostructure photocatalyts.Then,emphatically summarized the topic of“Several TiO₂ array nanostructure thin films fabrication and their photoca talysis properties”carried out the main research work,during the author studying for master degree.The specific research results above and below:1.TiO₂ nanoparticles?TNPs?modified ultrathin Na₂ Ti₉O₁₉ heterostructural nanosheets arrays are successfully synthesized by novel two-step hydrothermal growth method.O ur investigation of their photocatalytic degradation methyl orange?MO?under simulated sunlight irradiation suggests that TiO₂@Na₂Ti₉O₁₉ nanosheets possess dramatically enhanced photocatalytic activity,and their degradation efficiency is nearly 2.4 times higher than that of the pure Na₂Ti₉O₁₉ nanosheets arrays for 2 h.After 4 cycles,their photocatalytic activities are kept almost unchanged,showing perfect reusability and superior stability,which would be attributed to their uniquely oriented heterostructural nanosheet arrays,matched energy level structure,and intimate interface contact.2.Vertically aligned TiO₂ nanocones?TNCs?array films are successfully synthesized by a facile one-step hydrothermal growth method on Ti substrate.The physical and chemical properties of TNCs are characterized by X-ray diffraction?XRD?,field emission scanning electron microscopy?FESEM?and UV-vis absorption spectra.The simulated sunlight-driven photocatalytic activity of TiO₂ dense films?TDFs?and TNCs are measured by photodegradation of methyl orange?MO?aqueous solution.The results show that their photocatalytic degradation methyl orange?MO?under simulated sunlight irradiation suggests that TNCs possess dramatically enhanced photocatalytic activity,and their degradation efficiency is nearly 2.2 times higher than that of the TDFs for 2 h and the TNCs photodegradation rate?K?reaches to 0.01624 min^-1 which is 4 times to that of TDFs samples under the same conditions.The single phase TNCs is significant to improve the photocatalytic performance,mainly due to their unique morphology structure,vertical and orderly nanocone arrays provide large specific area,more reaction sites and efficient light harvesting.Furthermore,adjusted the hydrothermal time to optimize morphology of TNCs and explore the controllable growth mechanism of the vertically aligned TNCs.Comparative study the different morphology of TNCs,we found that the vertically aligned TNCs possess the optimal photocatalytic properties.