Preparation,Modification And Properties Of MSU Mesoporous Molecular Sieves Based On Industrial Silicon Slag With Zirconium

The rapid economic development has also brought many environmental problems while providing people with a high quality of life.In particular,a large number of industrial solid wastes have become increasingly prominent.This facilitates the synthesis of highly active and doped mesoporous molecular sieves inexpensively because some industrial solid wastes contain both silicon species and.transition metal elements.In this paper,Zr-MSU mesoporous molecular sieves have been successfully prepared in the conventional hydrothermal system using industrial silicon slag with zirconium as raw materials.Titanium-zirconia co-doped Ti-Zr-MSU mesoporous molecular sieves were successfully prepared by adding butyl titanate.Both materials show good catalytic properties.The specific research results are as follows:1.We used mixed surfactant system as template for the synthesis process of Zr-MSU mesoporous molecular sieves that are with high degradation property.In the synthesis process,cationic surfactants(we use Cetyltrimethylammonium bromide CTAB in this paper)were mainly used,and other surfactants(such as nonionic surfactants polyoxyethylene octyl phenyl ether-10,OP-10;neutral primary amine dodecylamine,DDA;and anionic surfactant sodium dodecyl benzene sulfonate,SDBS and Sodium dodecyl sulfate(SDS)supplemented.2.We explored the influence of different conditions on the synthesis process by changing the main synthesis parameters(such as water-to-silicon ratio,crystallization time,crystallization temperature,etc.).The results show that the optimum synthesis system is the mixed anionic and cationic surfactants(CTAB and SDBS)and the suitable mole ratios of Surf/SiO2 and H2O/SiO2 are 0.15 and 58,respectively.The optimized crystallization temperatures and time are 100? and 48h,respectively.The morphology of the samples obtained under optimal conditions is mostly spherical with a three-dimensional worm-like pore structure.The pore size of the sample is 5.55 nm and the elements in the sample are evenly distributed.We used the degradation process of methyl blue as a probe to investigate the influence of the Zr-MSU mesoporous molecular sieves on the degradation process and the degradation mechanism.The results showed that the trace amounts of radioactive elements in the silicon slag can initiate free radical reactions,and the strong acid sites formed by zirconium elements can strengthen the degradation process.3.The titanium-zirconium co-doped Ti-Zr-MSU mesoporous molecular sieves were successfully synthesized by adding butyl titanate.Compared with the difference in the performance of the modified and unmodified mesoporous molecular sieves,we found that:the pore size of the synthesized Ti-Zr-MSU mesoporous molecular sieves was 9.45 nm;the elements were uniformly distributed and the Ti and Zr were all distributed on the zeolite sieve with +4 valences.The photodegradation experiments of Rhodamine B showed that the ability of Ti-Zr-MSU sample to degrade Rhodamine B was much greater than that of Zr-MSU.During the whole degradation process,the dissociation of ethyl group and the degradation process of the chromogenic group(the hydroxyl radical initiation process)exist simultaneously,but the degradation process of the chromophore group plays a major role.The prepared Ti-Zr-MSU mesoporous sample has photocatalytic activity and can be used as a catalyst in the photocatalytic production of hydrogen,while the Zr-MSU sample does not have the property to photolyze water to produce hydrogen The main reason is that the bandgap energy of TiO2(3.2eV)is lower than that of ZrO2(5eV),and the ultraviolet energy under experimental conditions can only overcome the electronic transition of Ti02 from the valence band to the conduction band.4.These two mesoporous molecular materials can catalyze the degradation of medical wastewater,but the degradation property of Ti-Zr-MSU mesoporous samples is much greater than Zr-MSU.The main reason is that Ti element can initiate photodegradation,while Zr element is not obvious.The above results showed that the research work has great research value in theoretical research and practical application.