Soltan Sahar, Jafari Hoda, Afshar Shahrara, Zabihi Omid
College of Chemistry, Iran University of Science and Technology, Narmak PO Box 16844-13114, Tehran, Iran E-mail:
Institute for Frontier Materials, Deakin University, Geelong, Victoria 3216, Australia.
Water Sci Technol. 2016 Oct;74(7):1689-1697. doi: 10.2166/wst.2016.343.
In the present study, silicon dioxide (SiO) nanoparticles were loaded to titanium dioxide (TiO) nano-particles by sol-gel method to make a high porosity photocatalyst nano-hybrid. These photocatalysts were synthesized using titanium tetrachloride and tetraethyl orthosilicate as titanium and silicon sources, respectively, and characterized by X-ray powder diffraction (XRD) and scanning electron microscope methods. Subsequently, the optimizations of the component and operation conditions were investigated. Then, nano-sized TiO and TiO-SiO were supported on concrete bricks by the dip coating process. The photocatalytic activity of nano photocatalysts under UV irradiation was examined by studying the decomposition of aqueous solutions of furfural and acetophenone (10 mg/L) as model of organic pollutants to CO and HO at room temperature. A decrease in the concentration of these pollutants was assayed by using UV-visible absorption, gas chromatography technique, and chemical oxygen demand. The removal of these pollutants from water using the concrete-supported photocatalysts under UV irradiation was performed with a greater efficiency, which does not require an additional separation stage to recover the catalyst. Therefore, it would be applicable to use in industrial wastewater treatment at room temperature and atmospheric pressure within the optimized pH range.
在本研究中,通过溶胶 - 凝胶法将二氧化硅(SiO₂)纳米颗粒负载到二氧化钛(TiO₂)纳米颗粒上,制成高孔隙率的光催化剂纳米复合材料。这些光催化剂分别使用四氯化钛和原硅酸四乙酯作为钛源和硅源合成,并通过X射线粉末衍射(XRD)和扫描电子显微镜方法进行表征。随后,研究了组分和操作条件的优化。然后,通过浸涂工艺将纳米尺寸的TiO₂和TiO₂ - SiO₂负载在混凝土砖上。通过研究糠醛和苯乙酮(10 mg/L)水溶液在室温下作为有机污染物模型分解为CO₂和H₂O,考察了纳米光催化剂在紫外光照射下的光催化活性。使用紫外 - 可见吸收、气相色谱技术和化学需氧量测定这些污染物浓度的降低情况。在紫外光照射下,使用混凝土负载的光催化剂从水中去除这些污染物的效率更高,且不需要额外的分离步骤来回收催化剂。因此,它适用于在室温、大气压以及优化的pH范围内用于工业废水处理。