Study On The Preparation Of Three-dimensional Ordered Macroporous Materials By Two Times Template Method And The Study Of Photocatalytic Properties

In recent years,environmental air quality has deteriorated and volatile organic compounds?VOCs?pollution is serious in our country.In outdoor,it is an important pollutant in air pollution.In the room,the VOCs released by the decoration paint also endangers people's health at all times.Among the many methods to control VOCs gas,photocatalytic degradation of organic gases has attracted more and more attention because of its green and pollution-free characteristics.It is a promising way to control VOCs pollution.The three dimensional ordered macroporous?3DOM?materials prepared with silica?SiO₂?colloidal template have better properties than ordinary photocatalytic nanomaterials,which can make the pore arrangement of the materials closely and orderly and the size of the pore size can be adjusted.It has been proved that the photocatalytic properties of nanomaterials can be improved.However,the removal of the template is needed for hydrofluoric acid?HF?,and HF can react with most metal and metal oxides,which limits its application in the preparation of 3DOM metal oxide materials and on the composite or modification of non-metallic materials.In order to expand the application range of silicon dioxide template,the SiO₂ colloidal template was filled with glucose solution as precursor solution.The macroporous carbon with complete SiO₂ template reverse replication structure was obtained by dissolving the SiO₂ template by carbon material without the reaction with HF.On the basis of this study,a series of nanomaterials with three dimensional ordered macroporous structures were prepared by using macroporous carbon as the two template and using different catalyst modification methods.The macroporous carbon materials can be degraded by themselves during the calcination process,and the corrosion of metal oxides has been solved successfully.The modification of two directions of Micromorphology control and self energy band structure of the photocatalyst is realized.Three dimensional ordered macroporous CeO₂/TiO₂?3DOM CeO₂/TiO₂?was prepared by two times template method combined with semiconductor compound,and VOCs gas was simulated with 200ppm toluene.The optimum preparation conditions of the composite were investigated by single factor investigation,and the samples were characterized and combined with various characterization atlas.It was found that 3DOM CeO₂/TiO₂ inherited the three-dimensional order.The specific surface area of the material is greatly increased.When the molar ratio of n?Ce?/N?Ti?is 0.7:1,the photocatalytic efficiency is the highest.The3DOM CeO₂/TiO₂ catalyzed under the best condition is 60 min under visible light,and the degradation rate of toluene is 94%.3DOM Gd-N/TiO₂ was prepared by two times template method combined with element doping.The optimum proportion of Gd-N elements was investigated by single factor investigation.It was found that when the proportion of Gd and N elements was 0.6%and0.24%,the photocatalytic performance was the best,the band gap width decreased obviously,and the composite catalyst inherited the same.The excellent micromorphology of macroporous materials can catalyze 60 min under visible light and the degradation rate of toluene is 92%.Finally,in order to detect the applicability of the two template method to non-metallic nanomaterials,three dimensional ordered macroporous graphite phase carbon nitride?3DOM g-C₃N₄?was prepared by different precursor systems.The degradation ability of VOCs gas was investigated by simulated VOCs gas and 1 h under the 300 W xenon lamp.The results showed that the 3DOM g-C₃N₄,prepared by the two templating method,was to toluene.The degradation rate reached 91%,which is mainly due to the increase of specific surface area due to the excellent pore structure of the catalyst.