One-step synthesis of novel PANI–Fe3O4@ZnO core–shell microspheres: An efficient photocatalyst under visible light irradiation

For the first time, novel multifunctional superparamagnetic PANI–Fe 3 O 4 @ZnO core–shell composite photocatalysts with different PANI: ZnO ratios were synthesized by Pickering emulsion route in one step in the presence of ZnO nanoparticles. PANI–Fe 3 O 4 @ZnO core–shell microspheres consist of PANI core which embedded with Fe 3 O 4 -OA (oleic acid modified Fe 3 O 4 ) nanoparticles and tunable ZnO shell thickness. The resulting samples were thoroughly studied by using X-ray diffraction (XRD), X-ray photoelectron spectra (XPS), transmission electron microscopy (TEM), scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). The catalytic activity of the as-prepared PANI–Fe 3 O 4 @ZnO core–shell microspheres is investigated by the degradation of MB under visible light irradiation. As expected, the as prepared PANI–Fe 3 O 4 @ZnO photocatalysts exhibit highly enhanced photocatalytic activities in the degradation of MB under visible light irradiation owing to fast separation of photo-generated electron-hole pairs. Significantly, the PANI–Fe 3 O 4 @ZnO catalysts can be separated from the reaction media by applying an external magnet, and can be reused for seven cycles without change in stability and degradation efficiency.