سال انتشار: ۱۳۹۱

محل انتشار: سومین همایش علوم و فناوری مواد فعال سطحی و صنایع شوینده

تعداد صفحات: ۲۱

نویسنده(ها):

Tecush Mohammadi – Chemistry Department, Isfhan University, Isfhan, Iran
Asghar Zeini Isfhani – Falavarjan Branch, Islamic Azad University, Falavarijan, Isfahan, Iran

چکیده:

The heterogeneous photocatalytic oxidation of oxalic acid over bare TiO(2) and metal-modified TiO(2) has been studied. The UV irradiation source was a 400W high-pressure mercury lamp and a stirred photochemical reactor that was cooled by a water circular system has been used. The effects of the temperature and the amount of copper and silver coated on Tio(2) have been explored. An optimum loading of 5% Ag or 5% Cu was observed for photooxidation of oxalic acid. Surface modification of TiO(2) with both of metallic Ag and Cu, was improved the activity of photocatalysts, but, Ag/TiO(2) has more photocatalytic activity than Cu/TiO(2) (16%, for same concentration of metal loaded on TiO(2)). Loaded Ag and Cu on TiO(2) can promote the transfer of electron in TiO(2) conduction band to outer oxygen, which is dissolved in water. Relatively lower photocatalytic activity of Cu/TiO(2) conduction band to outer oxygen, which is dissolved in water. Relatively lower photocatalytic activity of Cu/TiO(2) than of Ag/TiO(2) is ascribed to the location of Cu energy level, which is not so much appropriate in transferring the electrons to outer oxygen as that of Ag. The reaction rate of photocatalytic degradation of the oxalic acid follows a zero kinetic order according to the Langmuir-Hinshelwood model.