Rashid Jamshaid, Barakat M A, Ruzmanova Y, Chianese A
Department of Environmental Sciences, Faculty of Meteorology and Environment, King Abdulaziz University (KAU), Jeddah, Saudi Arabia,
Environ Sci Pollut Res Int. 2015 Feb;22(4):3149-57. doi: 10.1007/s11356-014-3598-9. Epub 2014 Sep 21.
Photocatalysis has emerged as an advance and environmental-friendly process for breakdown of organic contaminants in wastewater. This work reports facile synthesis and characterization of stable magnetic core-shell-shell Fe3O4/SiO2/TiO2 nanoparticles and their effectiveness for photocatalysis. The surface morphology, crystal structure, and chemical properties of the photocatalyst were characterized by using scanning electron microscope (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), and nitrogen physisorption. Stability of synthesized nanoparticles in aqueous medium was tested by leaching test. The photocatalytic degradation of 2-chlorophenol was investigated and reaction parameters for best catalyst performance were optimized. Catalyst dose of 0.5 g/L under optimized conditions produced complete degradation of 25 mg/L 2-chlorophenol (2-CP) within 130 min of 100-W ultraviolet (UV) irradiation while 97.2 % degradation of 50 mg/L 2-CP was achieved within 3 h. The rate of photocatalytic degradation was determined by considering pseudo first-order kinetics and Hugul's kinetic equations. The Hugul's kinetics was found to provide a better interpretation of the experimental results than the generally adopted pseudo first-order reaction kinetics.
光催化已成为一种先进且环保的处理废水中有机污染物的方法。本研究报告了稳定的磁性核壳壳结构Fe3O4/SiO2/TiO2纳米粒子的简便合成与表征及其光催化效果。通过扫描电子显微镜（SEM）、能量色散X射线（EDX）、X射线衍射（XRD）和氮物理吸附对光催化剂的表面形貌、晶体结构和化学性质进行了表征。通过浸出试验测试了合成纳米粒子在水介质中的稳定性。研究了2-氯苯酚的光催化降解，并优化了最佳催化剂性能的反应参数。在优化条件下，0.5 g/L的催化剂剂量在100 W紫外线（UV）照射130分钟内可使25 mg/L的2-氯苯酚（2-CP）完全降解，而在3小时内可实现50 mg/L的2-CP 97.2%的降解。通过考虑准一级动力学和休古尔动力学方程来确定光催化降解速率。结果发现，与普遍采用的准一级反应动力学相比，休古尔动力学能更好地解释实验结果。
