Modified surficial chemistry micro-circumstance and mid-gap effect on photocatalytic ability of tetracycline by introducing of nitrogen in Fe2(MoO4)3

A novel non-metal doped Fe-2(MoO4)(3) photocatalyst with flower-like microstructure was synthesized by a hydrothermal method. The incorporation location of nitrogen was proved by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). UV-Vis diffuse reflectance spectroscopy (DRS) revealed mid-gap from the dope of nitrogen strongly enhanced the visible-light absorption ability. Scanning electron microscopy (SEM) showed that the morphology of dbped samples was greatly influenced by nitrogen dopant. Significantly, N-doped Fe-2(MoO4)(3) exhibits an ideal tetracycline (TC) photocatalytic ability, which can be a potential function material for antibiotics degradation. Photoluminescence (PL) and photocurrent indicated that constract of oxygen vacancy, which modified the surficial chemistry micro-circumstance, greatly depressed the recombination rate of the photo-generated electron-hole pairs. In order to investigate the possible mechanism of promoted TC degradation efficiency, radical trapping experiments of pure Fe-2(MoO4)(3) and N-doped samples were examined. It was found that superoxide radicals (center dot O-2(-)) and hydroxyl radical (center dot OH) formed in the visible light excitation process play an important role in the fragmentation reaction. Moreover, the possible ring-opening intermediates were deduced and a reasonable enhancement mechanism of N-doped Fe-2(MoO4)(3) TC degradation was also investigated in this study. This investigation could provide an effective reference for doping non-metallic species for improving the photocatalytic activity of Fe-2(MoO4)(3). (C) 2017 Elsevier B.V. All rights reserved.