Graphene@ZnO nanocompound for short-time water treatment under sun-simulated irradiation: Effect of shear exfoliation of graphene using kitchen blender on photocatalytic degradation

Highly efficient visible light-driven photocatalysts applied to remediate organic pollutants are demanded in environmental applications. To activate the transition metal oxides such as zinc oxide (ZnO) in photocatalysis under visible light, the graphene is one of most promising materials but its useful properties depends dramatically to synthesis method. For the first time, we reported that the shear-exfoliated graphene can be used to fabricate the visible light-driven graphene/zinc oxide (G/ZnO) photocatalyst via a simple single-stage method. The physical and structural properties of the prepared G/ZnO nanocomposites were investigated by XPS, SEM, TEM, BET, FTIR, XRD and UV–Visible spectroscopy. At the best result, the degradation of methylene blue ∼99% was achieved by using shear-assisted exfoliated graphene on ZnO nanowires within only 90 min (or 95% after 60 min). Other made photocatalysts eliminated more than 99% of pollutant model within 180 min. As conclusion, 1) shear-assisted exfoliation is one of the best graphene synthesis methods to apply in photocatalysis. 2) There is an optimum amount of graphene to activate the ZnO under visible or sun light. 3) Addition to graphene amount, the precursor type of ZnO is also important in high-activity of G/ZnO photocatalysts.