Controllable Synthesis And Photocatalytic Properties Study Of TiO₂ Nanowires

As a kind of n–type semiconductor material,TiO₂ has been widely used in the field of photocatalysis because of its excellent catalytic properties,stable chemical properties and safety.With the rapid development of nanomaterials,semiconductor has combined with nanotechnology closely.Variety of TiO₂ nanomaterials,including nanocrystal,one-dimensional,two-dimensional and three-dimensional have been successfully synthesized by a lot of methods.However,TiO₂ nanowires is considered as the most effective structure of catalytic properties.It is worth noting that growth of TiO₂ nanowires can be better controlled directionally by template method,but the high cost of preparation leads to limited scale.Therefore,low cost and high efficiency preparation of TiO₂ nanowires has become a research focus in this field.In this paper,with synergistic regulation of OLA / hydrazine,TiO₂ nanowires were obtained by hydrothermal method.Besides the relationship of morphology and photocatalytic performance,synthesis mechanism of raw material composition and process conditions on the morphology of TiO₂ nanowires was discussed.This thesis not only enriched basic research contents of TiO₂ nanowires,but also provided a useful technological support for potential applications of TiO₂ nanowires.The main work of this paper were as follows:?1?The hydrothermal synthesis of TiO₂ nanowires and synergistic regulation of OLA / hydrazineUsing TALH as Ti source,oleic acid and hydrazine as synergistic control agent,NaOH solution as solvent,TiO₂ nanowires were successfully synthesized by hydrothermal reaction.By adjusting the molar ratio of Ti source and synergistic control agent,reaction temperature and reaction time,morphology of nanowires could be controlled in the nanometer size range.The results showed that TiO₂ nanowires synthesized with Ti: OLA: hydrazine = 1: 2: 4,at 200 ? for 24 h could be obtained with the characterized crystal surface of?100?and the characterized crystal direction of [001].?2?Photocatalytic effect of TiO₂ nanowires with different morphologies on Rhodamine-BDegradation of Rhodamine-B was achieved in aqueous solution with TiO₂ nanowires synthesized by hydrothermal reaction.Experiments showed that TiO₂ nanowires synthesized had excellent adsorption properties.Moreover,under the UVirradiation,the photocatalytic activity of TiO₂ nanowires was two times as much as P25.It showed that TiO₂ nanowires own the potential of higher efficiency or better effect in the treatment of organic pollutants in water.?3?The adsorption behavior of Rhodamine-B on anatase TiO₂?100?The adsorption behavior of Rhodamine-B on anatase TiO₂ was conducted with the Material Studio simulation software based on first principles calculation.The 2×1periodic flat plate model was built and optimizedly calculated by CASTEP module,and the band structure and density of the anatase TiO₂?100?surface before and after adsorption were achieved.The results of the simulation showed that the molecule adsorption and dissociative adsorption of Rhodamine-B on the TiO₂?100?surface existed simultaneously,but the dissociative adsorption is the dominated adsorption behavior.