Surface Modification With Organic Molecules?Characterization And Performance Testing Of TiO₂

Of diverse environmental pollution treatment technology,TiO₂ semiconductor oxide as catalyst has become a popular,efficient and ideal technology for pollutants by heterogeneous photocatalytic degradation.The nano-TiO₂ has high surface area and its size between at 1-100 nm.Because of its physical and chemical properties such as small size effect,surface effect,quantum size effect,it is intensively applied in the environment,materials,medical and health,etc.But in practical application,because of its strong polarity,easy aggregation and low utilization rate etc,its application and excellent function are limited seriously.Therefore,by surface modification to improve performance of TiO₂ has become a hotspot in research.Presently,there are many methods of surface modification for TiO₂,this article used organic molecules that have long chain linear amine and acid to modify the surface of TiO₂.In this paper,taking tetrabutyl titanate as raw materials,nano-TiO₂ was modified with situ modified organic molecules that were improved by sol-gel method.The crystal and shape of particles were analyzed and characterized by X-ray diffraction?XRD??Fourier transform infrared spectra?FT-IR?? High resolution transmission electron microscopy?HRTEM?.Using the TiO₂ as catalyst,and selecting typical azo dye such as methyl orange and methylene blue as goal pollutants.Compared the adsorption and catalytic performance of the nano-TiO₂ that was modified with different organic molecules,to explore the impact of different organic molecules for nano-TiO₂ on adsorption and catalytic degradation of methyl orange and methylene blue.The influence factors of pH value,concentration of organic,catalyst dosing quantity on catalytic activity were also studied.The results of characterization showed that the nano-TiO₂ had uniform size and its surface had good modification effect.It was a completely anatase type.Through adsorption and photo-catalytic degradation of methyl orange and methylene blue,we found that the modification of organic molecules had a significant influence on the adsorption and catalytic activity for sample.It can improve the photo-catalytic activity of the catalyst,and the adsorption equilibrium time also increased accordingly.The experiment also indicated that the adsorption and catalytic degradation efficiency of methyl orange for the sample modified with the long chain linear amine organic molecules was better than the sample modified with the long chain linear acid type organic molecules.On the contrary,the adsorption and catalytic degradation efficiency of methylene blue for the sample modified with the long chain linear acid organic molecules was better than the sample modified with the long chain linear amine type organic molecules.According to the experiment,we found that the difference degradation efficiency mainly because the interaction of the charge for organic molecules and solution,In addition,the length of carbon chain organic molecules was also an impact on the photocatalytic activity of TiO₂,the general law was that the longer chain length of the surface modified organic molecular,the better adsorption catalytic efficiency we can get.