Highly efficient Zr-MOF@WO3/graphene oxide photocatalyst: Synthesis, characterization and photodegradation of tetracycline and malathion

In this study, for the first time, a novel MOF based nanocomposite, UiO-66@ WO3/graphene oxide (UiO-66@WG) was synthesized by a solvothermal method and its ability was evaluated for photodegradation of two pollutant models containing aromatic (tetracycline (TC)) and nonaromatic (malathion (MA)). The characterization of nanocomposite was performed by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and N-2 adsorption-desorption technique. The best efficiencies (84% and 100% for TC and MA respectively) obtained using UiO-66@35WG under 70 min visible light irradiation which is noticeably more efficient when compared with pure UiO-66. This enhancement arises from several aspects containing increase in visible light response, proper matching of conductive and valence bands belong to UiO-66 and WO3 that led to improved separation of electron-hole pair and faster transfer of photoinduced carriers on layers of graphene oxide. The reduced band gap, various functional groups and good availability of active sites also are other positive factors in this design. The total oxygen carbon (TOC) analysis indicated 75%, 83% mineralization efficiency for TC and MA respectively, indicating acceptable decomposition of these pollutants under optimum condition. Furthermore, this nanocomposite shown good reusability after 4 consecutive runs.