Ảnh hưởng của hàm lượng magiê đến cấu trúc và hoạt tính của chất xúc tác quang TiO2 trong phản ứng phân huỷ phenol với ánh sáng UV-VIS

Abstract

In this study, MgO loaded TiO₂ Degussa P25 powders were prepared by wet impregnation with difference of Mg amount content (i.e 0.5-10%). X-ray patterns studies have not proven the new phases in the MgO loaded TiO₂ catalysts as well as BET and SEM studies have not shown the change of its particle size and specific surface area in compared with initial TiO₂. The PZC values of TiO₂-Mg samples were higher than that of TiO₂-P25 and increased with the enhancement of Mg amount. The higher the PZC values were, the lower the saturated adsorption of TiO₂ surface to phenol was, because of the basicity of MgO and the negatively charged catalyst surface. The photocatalytic degradation of phenol by using MgO loaded (0.5-10% w/w in Mg) TiO₂ catalysts has been studied. Catalyst with ~1% w/w Mg content shows a better catalytic behavior than non-loaded TiO₂. If the Mg amount was increased more than 1%, the activity of Mg coated TiO₂ decreased. The MgO enhancement of photocatalytic activity of TiO₂ with optimal content ~1% Mg under UV-Visible light may be due to the ability of trapping of photogenerated electron of MgO.