Synthesis and Visible-Light-Driven Photocatalytic Activity of Nitrogen-Doped HTi2NbO7 Nanosheet

Firstly, layered CsTi2NbO7 was prepared by high temperature solid-state method, and then layered HTi2NbO7 was obtained by a proton-exchange reaction treated with HNO3 solution. Secondly, the obtained layered HTi2NbO7 was well dispersed in tetrabutylammonium hydroxide (TBAOH) solution in order to prepare HTi2NbO7 nanosheets by exfoliation reaction. Thirdly, the as. prepared HTi2NbO7 nanosheets were dried, and then mixed with urea. Finally, nitrogen-doped HTi2NbO7 nanosheet photocatalyst was successfully synthesized by heating the above mixture. The as. prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), Ultra-violet-Visible diffuse reflectance absorption spectrum (UV-Vis DRS) as well as N-2 adsorption-desorption measurements to characterize the crystal structure, morphology, specific surface area, pore distribution and light absorption capacity of as. prepared samples in detail. It was found that the doped nitrogen resulted in an intrinsic narrowing band. gap so as to widen light response region, and the doped nitrogen atoms were mainly located at the interstitial position of Ti2NbO7- sheets and chemically bonded with hydrogen ions. Moreover, compared with N-doped HTi2NbO7, N-doped HTi2NbO7 nanosheets had a larger specific surface area and richer mesoporous structure due to the relatively loose and irregular arrangement of the titanium niobate nanosheets. Therefore, the N-doped HTi2NbO7 nanosheets exhibited higher visible. light photocatalytic activity for degradation of RhB than that for N-doped layered HTi2NbO7.