Facile synthesis of magnetic Fe@Al-ZnO nanocomposite for photocatalytic bacterial inactivation under visible-light irradiation

Abstract Magnetic Fe@Al-ZnO nanocomposite was systhesized through a facile two-step precipitation process for the first time, and employed as a highly active photocatalyst for visible-light-driven (VLD) inactivation of Escherichia coli. The as-synthesized nanocomposite was analyzed using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), scanning electron microscope (SEM), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), UV–vis diffused reflectance spectra (UV–vis DRS) and photoluminescence (PL) spectra. The Fe@Al-ZnO photocatalysts displayed typical ferromagnetic property with the saturation magnetization of 35.2 emu/g, which predominantly facilitated magnetic separation and recycling in applications. The photocatalyst dosage was found to have a significant influence on the VLD photocatalytic bacterial inactivation activity of Fe@Al-ZnO. Under visible-light irradiation, 40 mg of Fe@Al-ZnO could entirely inactivate 7-log of bacterial cells in 5 h. Notably, the phase structure and magnetic property of the nanocomposite after photocatalysis exhibited almost no evident change compared with that before photocatalysis, indicating excellent stability of Fe@Al-ZnO photocatalyst. Due to the privileges of facile preparation, relatively low cost, powerful photocatalytic efficiency, excellent stability as well as magnetic recovery property, Fe@Al-ZnO nanocomposite was anticipated to possess remarkable potential in VLD photocatalytic inactivation of bacteria.