Enhancement of Catalytic Performance of MCM-41 Synthesized with Rice Husk Silica by Addition of Titanium Dioxide for Photodegradation of Alachlor

• Published in: EnvironmentAsia Vol. 2; no. 1; pp. 41 - 48
• Main Authors: Artkla, S, Choi, W, Wittayakun, J
• Format: Journal Article
• Language: English
• Published: Thai Society of Higher Eduction Institutes on Environment 01.01.2009
• Subjects: alachlor; Oryza sativa; photodegradation; RH-MCM-41; TiO2; titanium dioxide
• ISSN: 1906-1714

Photocatalytic degradation of alachlor, a herbicide, in water on both bare TiO sub(2) and TiO sub(2) supported on mesoporous material, marked as TiO sub(2)/RH-MCM-41 were studied. The RH-MCM-41 support was synthesized from rice husk silica and other reagents by hydrothermal method. The required amount of titanium precursor (TiO sub(2) P25 Degussa) to give 10-60% was mixed with RH-MCM-41 and calcined at 300 C for 6 h. The catalytic activities of TiO sub(2) and TiO sub(2)/RH-MCM-41 for alachlor degradation were performed under UV radiation with wavelength of 300 nm. The ratio of catalyst weight to volume of alachlor solution was 1 g/L and all products were characterized by high performance liquid chromatograph. The reaction equilibrium was established in 30 min. in deionized water without adjusting the solution pH. The TiO sub(2)/RH-MCM-41 could adsorb alachlor more than the bare TiO sub(2) (namely, 17% vs. 5%) and the photocatalytic activity of alachlor degration on all TiCyRH-MCWMIs was higher than that on the bare TiO sub(2). By comparison per weight of TiO sub(2), the 10% TiO sub(2)/RH-MCM-41 gave the highest alachlor conversion of 100% after 20 min. while 1% bare TiO sub(2) showed conversion of 95%.