Preparation Of Hierarchical Porous Hybrid Materials By Sol-gel Phase Separation

Porous materials generally have the advantages of low relative density,high specific surface area,good permeability,excellent adsorption performance,and light weight.Compared with other dense materials with the same matrix,the porous material will make it have more excellent performance and more widely used.In the field of catalysis,the use of hierarchical pore materials as carriers can greatly increase the active site of the reaction,maximize the efficiency of the catalyst,and effectively increase the reaction yield.The sol-gel phase separation method is an emerging technology for preparing hierarchical pore bulk materials.The prepared materials have a continuous macroporous structure and controllable material morphology.Among them,the silica system is currently the most studied system with the most application value and potential.In this paper,the influence of various factors on pore structure in the preparation of pure silicon multistage porous blocks by sol gel phase separation with methyl orthosilicate?TMOS?as precursor was investigated,which optimal reaction ratio for forming continuous channels was obtained.That influence mechanism of the factors of phase separation rate and gelation rate was analyzed,and the pure silicon hierarchical pore block was used as the matrix to try to load the ferric oxide?Fe₃O₄?nanoparticles by solvothermal method to prepare the hierarchical pore block bulk catalyst to explore its degradation effect.On this basis,the preparation method of sol-gel phase separation in-situ doping was re-enacted to prepare copper-doped hierarchical porous hybrid materials.Copper nitrate?Cu?NO₃?₂?,aluminum nitrate?Al?NO₃?₃?and TMOS explored the optimal reaction ratio and related influence mechanism for the precursor.Scanning electron microscope?SEM?results show that after copper and aluminum are added,a continuous macroporous skeleton structure will be obtained when Si:Cu:Al=50:4:5.The doping of aluminum and copper and related mechanisms were explored through characterization methods such as energy dispersive spectrometer?EDS?,energy dispersive X-ray spectroscopy?EDX?,and X-ray photoelectron spectroscopy?XPS?.From the results of temperature programmed desorption?NH₃-TPD?,it is shown that the addition of aluminum will generate a large number of Br?nsted acid sites.The presence of acid sites makes copper successfully doped into the framework and forms a chemical bond.The addition of aluminum causes the problem of copper doping has been effectively solved,and hierarchical porous structure with large pores,mesopores and micropores.The prepared hierarchical porous bulk hybrid material was used in the degradation of methyl orange wastewater.It was found that the degradation rate of 99%.The degradation effect is obvious.Methyl orange wastewater can be achieved under the condition of pH 3 of the hierarchical porous Fenton catalyst loaded with Fe₃O₄ nanoparticles.The copper-doped hierarchical porous Fenton catalyst can achieve a degradation rate of about 69%under a pH of 6.The preparation of this material provides a reference for the preparation of redox catalysts in the fine chemical industry and environmental protection.