Kinetics and mechanism of enhanced photocatalytic activity under visible light irradiation using Cr2O3/Fe2O3 nanostructure derived from bimetallic metal organic framework

It is reported here for the first time, synthesis of hybrid metal oxide nanocomposites, Cr2O3/Fe2O3, from bimetallic Cr-Fe metal organic frameworks using temperature-programmed oxidation method. This facile method led to the production of high surface area photocatalyst. Cr2O3 and Fe2O3 were fabricated by thermal pyrolysis of Cr-BTC and Fe-BTC metal organic frameworks respectively. The prepared samples were characterized by XRD, IR, BET, XPS, SEM, TEM, PL, EDX and DRS. Fe3O4 as the sensitizer elevated the Cr2O3 photocatalytic activity. Furthermore, investigation of optical band gap demonstrated that Cr2O3/Fe2O3 is a visible-activated photocatalyst. With enhanced photocatalytic activity using acid blue 92 as an azo dye for photocatalyst activity investigations it was observed that after 20 min most of dyes were degraded and the solution turned colorless. The activities are due to the strong oxidative ability and efficient charge separation and transfer through the Cr2O3 and Fe2O3 in the form of composite. The photoreaction kinetics and mechanism with the nanostructures were studied.