Predominant role of grafted iron(III) Schiff-base complex in oxidation of gaseous and aqueous reactants: A visible light responsive photocatalyst

Abstract

The visible light response and photocatalytic activities of covalently bonded iron(III)-Schiff base complex is evaluated by photooxidation of nitric oxide under visible light exposure. In addition, this study reports the existing of dominant active sites on the surface of grafted complex toward water adsorption, which leads to the generation of hydroxyl radicals under illumination. Moreover, the morphological analysis exhibits high surface area (575 m 2 /g) with an average pore diameter of 21 nm; in this context, XRD analysis shows that the characteristic peaks of the Schiff-base complex are covered by the amorphous structure of the silica network, however, the microscopic analysis reveals the irregular shape of the grafted catalyst. Furthermore, the catalytic activity was evaluated by photooxidation of reactive blue 13 dye in aqueous solution under ambient light illumination. Also, the reaction variables such as the amount of catalyst, pH value, concentration and temperature of the dye solution were studied and discussed in detail. It seems, the enhanced activity of the photocatalyst toward the dye decolourization is a consequence of its uniform surface, large surface area, fine particles and active surface for the water adsorption.