New Template in Synthesis of Copper Tungsten -Mesoporous Silica for Photo Oxidative-Desulfurization of Dibenzothiophene

Abstract

A novel CuWO4/SiO2 heterojunction catalyst was successfully synthesized using a new sulfonamide derivative. The physical characteristics of the prepared samples were investigated by TGA, XRD, FTIR, SEM, UV, PL, and XPS. The prepared catalysts were applied as a nano photocatalyst for photooxidative desulfurization of dibenzothiophene under visible light using hydrogen peroxide as an oxidant. The photocatalytic oxidative desulfurization performances of the prepared samples were investigated. Various factors as the reaction time, dibenzothiophene concentration, catalyst dose, and the oxidizing agent dose were also studied. The prepared photocatalyst has high desulfurization activity in the removal of DBT under mild conditions. Results showed that the CuWO4/SiO2 exhibited considerably higher activity than neat support SiO2. Such improved photocatalytic activity is mainly attributed to the efficient separation of photogenerated electron-hole pairs on CuWO4/SiO2 heterojunction. Moreover, the synergistic effects of this photocatalytic oxidation and the green oxidant hydrogen peroxide played an essential role in desulfurization. The reaction is pseudo-first-order and can reach 98.6 % removal of dibenzothiophene after 70 min and 97.2% after four cycles.