Hydrothermal synthesis of CeO2/NaNbO3 composites with enhanced photocatalytic performance

A highly active photocatalyst CeO2/NaNbO3 is fabricated by a simple and facile hydrothermal method. The obtained photocatalyst composites are characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of the obtained samples is demonstrated by the photocatalytic degradation of the colorless antibiotic agent ciprofloxacin and the dye rhodamine B. The results reveal that CeO2/NaNbO3 composites exhibit a higher photocatalytic property than pure NaNbO3 under both UV and visible light irradiation. Furthermore, the optimum mass ratio of CeO2 in the CeO2/NaNbO3 composites is 2.0 wt%. The improved photocatalytic activity is attributed to the higher separation rate of the photo-induced electrons and holes, and the higher migration rate of the photogenerated charge in the interfacial region. Furthermore, the photoluminescence pectra, photocurrent, electrochemical impedance spectroscopy and trapping experiment are applied to demonstrate the photocatalytic reaction mechanism of the as-prepared samples. The result of the trapping experiment indicates that center dot OH radicals, center dot O-2(-) radicals and holes are all involved in the photocatalytic degradation process of RhB. Furthermore, a possible mechanism for the enhancement of the photocatalytic activity is also proposed. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.