TiO2/SiO2 aerogels with different molar ratio of SiO2/TiO2 were prepared via non-supercritical method using tetrabutyl titanate and silica sols as raw materials. The samples were characterized by TEM, SEM, BET, IR, XR...TiO2/SiO2 aerogels with different molar ratio of SiO2/TiO2 were prepared via non-supercritical method using tetrabutyl titanate and silica sols as raw materials. The samples were characterized by TEM, SEM, BET, IR, XRD and so on. The results indicate that the BET surface area of TiO2/SiO2 aerogels calcined at 550℃ which consisted of anatase structure of TiO2 with narrow distribution pores of 5-25 nm is as high as 357.89 m2·g-1. For the photocatalytic degradation of pyridine, the catalytic activities of TiO2/SiO2 aerogels are much higher than that of TiO2 powder. The photocatalytic activity of TiO2/SiO2 aerogels calcined at 800℃ is the optimum. The higher the content of SiO2, the higher the photocatalytic activity of TiO2/SiO2 aerogels. The cost for preparation of the aerogels is greatly reduced by using non-supercritical drying method, and the aerogels are hopefully applied in the treatment of industrial waste water such as coking effluent treatment.展开更多
An ambient pressure synthesis of SiO2/TiO2 binary aerogel was prepared through the low-cost precursors of titanium tetrachloride（TiCl4） and sodium silicate（Na2O·nSiO2）.After gelation,solvent exchange and surf...An ambient pressure synthesis of SiO2/TiO2 binary aerogel was prepared through the low-cost precursors of titanium tetrachloride（TiCl4） and sodium silicate（Na2O·nSiO2）.After gelation,solvent exchange and surface modification were performed simultaneously and the modified gel was finally dried under ambient pressure.Microstructural analyses by transmission electron microscope（TEM） indicate that fabricated SiO2/TiO2 aerogel composite shows similar sponge-like nanostructure as silica aerogel,and the Brunauer-EmmettTeller（BET） analysis shows that the specific surface area of the composite reaches 605 m^2/g,and the average pore size is 9.7 nm.Such binary aerogel exhibits significant photocatalytic performance in this paper for treating model pollutant of methyl orange（MO）,and the decolorizing efficiency of MO is detected as 84.9%after 210 mins exposure to UV light irradiation.Degraded gel suspends in the water so as to separate from solution for reuse,and after 4 times recycling,70%degradation efficiency can be easily reached when composite catalyzed system is exposed for 210 mins under UV irradiation.展开更多
Titanium dioxide has been considered to be one of the most effective and environmental friendly photocatalytic material.It has been widely used in photocatalytic degradation of various pollutants.As we known,an anatas...Titanium dioxide has been considered to be one of the most effective and environmental friendly photocatalytic material.It has been widely used in photocatalytic degradation of various pollutants.As we known,an anatase crystal form typically obtained by high temperature heat treatment(>600℃),usually shows higher catalytic activity.In order to further improve the catalytic efficiency,we prepared TiO2 with a non-supercritical drying method to form a high specific surface area aerogel structure,along with an increased active contact site.However,with the inevitable of internal pores collapse in the process of high temperature crystallization,a large amount of porous structure and specific surface area is reduced.Here,to enhance the photocatalytic activity of titania,we propose a synergistic strategy to fabricate a porous titania structure with a high specific surface area.It was crystallized at a lower temperature(120℃) in a low-boiling solvent(ethanol,acetone,etc.).The lattice structure was identified by X-ray diffractometry;specific surface area(over 300 m2/g) of our sample was also measured through BET test;in the subsequent photocatalytic degradation test,the photocatalytic degradation efficiency of fabricated TiO2 is proved to be more excellent than P25 powder.By a freeze-drying/mild crystallization method,a high-specific surface area and high catalytic activity TiO2 aerogel was synthetized.This study provides some insights in the combining of crystallization and high specific surface area of titanium dioxide photocatalysis.展开更多
基金Supported by the National Natural Science Foundation of China (No. 20473057)Development Foundation of Science and Technology of Shanghai (No. 0352nm094).
文摘TiO2/SiO2 aerogels with different molar ratio of SiO2/TiO2 were prepared via non-supercritical method using tetrabutyl titanate and silica sols as raw materials. The samples were characterized by TEM, SEM, BET, IR, XRD and so on. The results indicate that the BET surface area of TiO2/SiO2 aerogels calcined at 550℃ which consisted of anatase structure of TiO2 with narrow distribution pores of 5-25 nm is as high as 357.89 m2·g-1. For the photocatalytic degradation of pyridine, the catalytic activities of TiO2/SiO2 aerogels are much higher than that of TiO2 powder. The photocatalytic activity of TiO2/SiO2 aerogels calcined at 800℃ is the optimum. The higher the content of SiO2, the higher the photocatalytic activity of TiO2/SiO2 aerogels. The cost for preparation of the aerogels is greatly reduced by using non-supercritical drying method, and the aerogels are hopefully applied in the treatment of industrial waste water such as coking effluent treatment.
基金Funded by the National Natural Science Foundation of China(NSFC)(Nos.51278073,51308079 and 51408073)
文摘An ambient pressure synthesis of SiO2/TiO2 binary aerogel was prepared through the low-cost precursors of titanium tetrachloride（TiCl4） and sodium silicate（Na2O·nSiO2）.After gelation,solvent exchange and surface modification were performed simultaneously and the modified gel was finally dried under ambient pressure.Microstructural analyses by transmission electron microscope（TEM） indicate that fabricated SiO2/TiO2 aerogel composite shows similar sponge-like nanostructure as silica aerogel,and the Brunauer-EmmettTeller（BET） analysis shows that the specific surface area of the composite reaches 605 m^2/g,and the average pore size is 9.7 nm.Such binary aerogel exhibits significant photocatalytic performance in this paper for treating model pollutant of methyl orange（MO）,and the decolorizing efficiency of MO is detected as 84.9%after 210 mins exposure to UV light irradiation.Degraded gel suspends in the water so as to separate from solution for reuse,and after 4 times recycling,70%degradation efficiency can be easily reached when composite catalyzed system is exposed for 210 mins under UV irradiation.
基金supported by the National Construction Program of First-Class University and First-Class Discipline of Chinathe Project of Novel Aerogel Materials Supported by Superel Advanced Materials Technology Co.Ltd of China。
文摘Titanium dioxide has been considered to be one of the most effective and environmental friendly photocatalytic material.It has been widely used in photocatalytic degradation of various pollutants.As we known,an anatase crystal form typically obtained by high temperature heat treatment(>600℃),usually shows higher catalytic activity.In order to further improve the catalytic efficiency,we prepared TiO2 with a non-supercritical drying method to form a high specific surface area aerogel structure,along with an increased active contact site.However,with the inevitable of internal pores collapse in the process of high temperature crystallization,a large amount of porous structure and specific surface area is reduced.Here,to enhance the photocatalytic activity of titania,we propose a synergistic strategy to fabricate a porous titania structure with a high specific surface area.It was crystallized at a lower temperature(120℃) in a low-boiling solvent(ethanol,acetone,etc.).The lattice structure was identified by X-ray diffractometry;specific surface area(over 300 m2/g) of our sample was also measured through BET test;in the subsequent photocatalytic degradation test,the photocatalytic degradation efficiency of fabricated TiO2 is proved to be more excellent than P25 powder.By a freeze-drying/mild crystallization method,a high-specific surface area and high catalytic activity TiO2 aerogel was synthetized.This study provides some insights in the combining of crystallization and high specific surface area of titanium dioxide photocatalysis.
