Application Research Of TiO₂/MCM-41in Analysis Of Metal Ions And Treatment Of Organic Pollutants

Heavy metal ions and organic pollutants are the main contaminants in water, effective treatmentof these pollutants is of great importance. In this paper, TiO₂/MCM-41composites were prepared byloading titania on the mesopores of MCM-41molecular sieves via different methods. ICP-AES wasused to determine actual TiO₂content in photocatalyst. Photocatalytic degradation and adsorption oforganic pollutants were investigated. Meanwhile, TiO₂/MCM-41was used to adsorb heavy metalions, and a new method of using solid waste was explored. The main research works are asfollowing:TiO₂/MCM-41composites with various titania content were prepared by loading titania on themesopores of MCM-41molecular sieves via sol-gel method, and were used as photocatalyst todegradate Rhodamine B （Rh B） and phenol. ICP-AES was used to determine actual TiO₂content inphotocatalyst, and the relevance between photocatalytic degradation and adsorption of organicpollutants was investigated, which rarely was mentioned in previous literatures. Experimental resultsdemonstrated that most of the Rh B was adsorbed instead of being degradated by TiO₂/MCM-41dueto the large specific surface area of MCM-41, while most of phenol was degradated. It turned out thatthe TiO₂/MCM-41with the highest Ti to Si ratio had the highest catalytic activity.Two different type of TiO₂/MCM-41were prepared via sol-gel and solvothermal method, andthe actual Ti/Si ratio were also determined. The structure were characterized by XRD、FTIR. Theinfluence of acidity, concentration, time and other factors on adsorption rate were investigated byICP-AES. The results demonstrated that the adsorbent exhibited good stability, high adsorptionselectivity, and is suitable to adsorb heavy metal ions in water.Cd/TiO₂/MCM-41and Pb/TiO₂/MCM-41after adsorbing heavy metal ions were recycledrespectively as photocatalyst to degradate RhB. The materials were characterized by XRD and FTIR.The photocatalytic activity of the composites with different heavy metal ions absorption undervarious adsorption conditions was discussed.