This paper describes a simple method for the modification of TiO2 surface with palladium to prepare a highly active photocatalyst for oxidation of benzene micropollutants in air. The method consists of the impregnation of anatase TiO2 with a solution of palladium (II) acetate (Pd(OAc)2) in acetone followed by photodecomposition of Pd(OAc)2 under UV irradiation. No additional electron donor is required for Pd photodeposition because acetate ligands play this role. Photodecomposition of Pd(OAc)2 can be efficiently performed either before the target photocatalytic reaction or in situ during the reaction. Pd-loaded photocatalysts were characterized using UV–vis DRS, XPS, TEM, EDX, and CO chemisorption techniques. The formation of metallic (Pd0) and oxidized (PdOx) palladium on the TiO2 surface was shown. An increased amount of metallic Pd was observed during photodecomposition of Pd(OAc)2 compared to its thermal decomposition at low temperature. The modification of TiO2 with Pd nanoparticles substantially increased its photocatalytic activity in the oxidation of benzene vapor under UV light. A Pd content of 1 wt.% was found to be optimum, which provided a three-fold increase in activity compared to pristine TiO2. In addition to increasing the oxidation rate, Pd nanoparticles suppressed the formation of CO as a byproduct during the process that increased the efficiency of air purification by the photocatalytic oxidation method. The proposed preparation techniques can be employed for easy modification of powdered photocatalysts or fabric filters used in photocatalytic air purifiers.
|Журнал||Colloids and Surfaces A: Physicochemical and Engineering Aspects|
|Состояние||Опубликовано - 5 мар 2021|