A facile synthesis for uniform tablet-like TiO2/C derived from Materials of Institut Lavoisier-125(Ti) (MIL-125(Ti)) and their enhanced visible light-driven photodegradation of tetracycline

摘要

The uniform tablet-like TiO2/C nanocomposites with two crystal types (rutile and anatase) and large specific surface area (438 m(2) g(-1)) were successfully prepared by Materials of Institut Lavoisier-125(Ti) (MIL-125(Ti)) calcined at a suitable temperature and applied for photocatalytic tetracycline (TC). The nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and mapping, N-2 adsorption-desorption isotherms, photoluminescence spectra (PL), photocurrent, and X-ray photoelectron spectroscopy (XPS). The changes of physicochemical parameters are discussed in detail. It is found that nanocomposite through suitable calcination temperature (M-A-800) with large surface area and appropriate micropore/mesopore ratio could strengthen separation and migration rates of photogenerated charge, resulting in the improvement of visible light photocatalytic activity of tetracycline, and exhibited about 2.0 times quicker than that of MIL-125(Ti). In addition, M-A-800 displayed favourable reusability and stability in four circulation tests. Finally, the reaction mechanism of photocatalyst and photodegradation pathway of tetracycline was also proposed. center dot O-2 was the most important active species, and dehydroxylation and decarboxylation were the main photodegradation pathway of tetracycline. (C) 2020 Elsevier Inc. All rights reserved.