Organic Silicon Template Inducing Synthesis Of Mesoporous Silica/Semiconductor Composite Photocatalyst And Research Of Its Performances

With the rapid development of industry, it has caused serious environmental pollution and health problems when a large number of pollutants were poured into the water. Nowadays, the method to deal with the water pollution problems included physical method, chemical method, biological method and photocatalytic technology et al. In this paper, the physical method and photocatalytic technology were combined. The strong adsorption of mesoporous SiO2and light response performance of semiconductor materials can also be combined. On the basis, removal of pollutants in wastewater can be realized by adsorption and light catalytic. Furthermore, ultraviolet light and visible light induced photocatalysts have been prepared successfully. In addition, its photocatalytic performance on dye such as RhB has also been explored. The paper mainly includes the following four parts:1. Silica-based hybrid microspheres:synthesis, characterization and wastewater treatment.Silica hybrid microspheres with280nm in diameter have been synthesized from tetraethyl orthosilicate (TEOS) and octadecyltrimethoxysilane (C18TMS). The morphology and size of the samples were investigated by field-emission scanning electron microscopy and transmission electron microscopy). The silica microspheres which exhibit excellent adsorption ability towards organic pollutants for instance, dyes, oils et al. Furthermore, the hydrophobic silica microspheres could be used as versatile templates for controlled synthesis of mesoporous silica hybrid materials.2. Preparation and performance research of mesoporous SiO2/CdS composite nanospheresUniform SiO2@CdS mesoporous nanospheres with an average diameter of300nmhave been synthesized successfully by a facile process. The as-prepared mesoporous composite nanospheres have a BET-specific surface area of640m2g-1and an average pore size of2.82nm. The as-prepared SiO2@CdS mesoporous nanospheres have a mesoporous nanostructure, suggesting a higher specific, surface area and resulting in strong adsorption ability. In addition, the mesoporous silica was decorated with ca.5nm CdS nanocrystals, which showed excellent photocatalytic activity under visible light and could rapidly remove most of the RhB molecules from a pollutant solution under visible light irradiation. Furthermore, the mesoporous SiO2@CdS nanospheres synthesized by the present protocol exhibited excellent antibacterial activity.3. Controllable preparation and photocatalytic performance test of the mesoporous SiO2/TiO2composite microspheresA mild solution route has been designed for the synthesis of uniform TiO2/SiO2composite microspheres with octadecyltrimethoxysilane(C18TMS) and tetrabutyl titanate at low temperature via a self-assembly process. The TiO2composite microspheres consisted of TiO2nanoparticles with several nanometers in diameter; and the size and morphology of the composite microspheres can be well controlled by controlling the reaction conditions. Octadecyltrimethoxysilane and reaction temperature play key roles in the formation of the composite microspheres. In particular, the synthesized composite microspheres exhibit strong anatase phase stability and good performance on photodegradation of RhB dye from the pollutant solution.4. Preparation and performance research of mesoporous SiO2@TiO2core-shell microspheresTiO2/SiO2composite microspheres have been synthesized successfully in the previous section, which have a small specific surface area (32m2g-1), so it has poor adsorption ability. Furthermore, because of the existance of SiO2, which forbids the effective separation of the electron-hole pairs in TiO2, resulting in the poor photocatalytic activity. In this charter, the SiO2@TiO2core-shell microspheres were obtained, and visible light induced photocatalysts have been prepared by N doping of TiO2.