Enhanced visible-light photocatalytic activity of BiOI–MWCNT composites synthesised via rapid and facile microwave hydrothermal method

Abstract

Novel BiOI–multi-walled carbon nanotube (MWCNT) composite photocatalysts have been prepared by one-step microwave hydrothermal method. The structures, morphology, optical properties and photocatalytic were studied by X-ray diffraction, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), diffuse reflection spectroscopy (UV–vis DRS), Brunauer–Emmett–Teller and photoluminescence methods etc. The results show that the BiOI–MWCNT composite exhibits increased photocatalytic than pure BiOI for decomposition of methyl orange (MO) and antibiotics agent levofloxacin (LEV). Meanwhile, the BiOI–MWCNT-1% composites showed highest photoactivity, the degradation rate constant is 2.4 times and 3.5 times higher than that of pure BiOI under the same conditions for degradation MO and LEV, respectively. The hole (h+) and superoxide radical (⋅O2−) were identified to be the dominant active species in the photocatalytic reaction.