TiO2/BiVO4, a Heterojuncted Microfiber with Enhanced Photocatalytic Performance for Methylene Blue under Visible Light Irradiation

摘要

Novel TiO2/BiVO4 microfiber heterojunctions were constructed using cotton as biomorphic templates.The as-synthesized samples were characterized by scanning electron microscope,X-ray diffraction,X-ray photoelectron spectroscopy,UV-Vis diffuse reflectance spectra and photocatalytic experiment.The morphology of the as-synthesized TiO2/BiVO4 composites was consisted of a large quantity of microfiber structures with diameter from 2.5 μm to 5 μm,and the surface of samples became more coarse and compact with the increase of weight ratio of TiO2.The TiO2/BiVO4 samples with proper content (10.00wt％) showed the highest photocatalytic degradation activity for methylene blue (MB) degradation among all the samples under visible light,and 88.58％MB could be degraded within 150 min.The enhancement of photocatalytic activity was mainly attributed to the formation of n-n heterojunction at the contact interface of TiO2 and BiVO4,which not only narrowed the band gap of BiVO4 for extending the absorption range of visible light,but also promoted the transfer of charge carriers across interface.A possible photodegradation mechanism of MB in the presence of TiO2/BiVO4 microfibrous photocatalyst was proposed.