Hydrothermal synthesis of novel flower-like BiVO4/Bi2Ti2O7 with superior photocatalytic activity toward tetracycline removal

摘要

A novel flower-like BiVO4 and BiVO4/Bi2Ti2O7 heterojunction photocatalyst was firstly synthesized by surfactant-free hydrothermal route, which is very convenient, rapid, controllable and environmentally friendly. The crystal structures, chemical composition, morphology, optical and photo-catalytic property of the as-prepared samples were characterized by the techniques of XRD, XPS, SEM, HRTEM, BET, UV-vis DRS, and PL. The BiVO4/Bi2Ti2O7 heterojunction photocatalyst exhibited higher photocatalytic activity than pure BiVO4 and Bi2Ti2O7 for the degradation of tetracycline (TC) under xenon lamp irradiation. The enhanced photocatalytic activities of BiVO4/Bi2Ti2O7 composites were either related to the particular structural features or the mass ratios of BiVO4 and Bi2Ti2O7 in the composites. The possible photocatalytic mechanism of the BiVO4/Bi2Ti2O7 composite has been speculated by detecting reactive species based on free radicals trapping experiments. The preliminary removal pathways of tetracycline was proposed on the basis of the identified intermediates using LC-TOF/MS. (C) 2016 Elsevier B.V. All rights reserved.