Hydrothermal synthesis and enhanced photocatalytic activity of hierarchical flower-like Fe-doped BiVO_4

Fe-doped BiVO4with hierarchical flower-like structure was prepared via a hydrothermal method using sodium dodecylbenzene sulfonate(SDBS)as structure directing agent.X-ray diffraction(XRD),scanning electron microscope(SEM),transmissionelectron microscope(TEM),high resolution transmission electron microscope(HRTEM),X-ray photoelectron spectroscopy(XPS)and UV-Vis were applied for characterization of the as-prepared samples.The formation mechanism of flower-like structure wasproposed based on the evolution of morphology as a function of hydrothermal time.Fe-doped into substitutional sites of BiVO4effectively improved the migration and separation of photogenerated carrier and enhanced the utilization of visible light.Flower-likeFe-doped BiVO4showed much higher visible-light-driven photocatalytic efficiency for degradation of methyl blue compared withthe pristine BiVO4.And the sample with a Fe/Bi mole ratio of2.5%showed the highest photocatalytic efficiency.

Photochemical synthesis and enhanced photocatalytic activity of MnO_x/BiPO_4 heterojunction

Monoclinic BiPO4with rod-like shape was prepared via a CTAB-assisted hydrothermal route.MnOx nanoparticles were loaded on the surfaces of BiPO4rods by a photo-deposition process to form MnOx/BiPO4heterojunctions.The as-prepared samples were characterized by XRD,SEM,TEM,XPS,FL,and UV-Vis diffuse reflectance measurements.The results showed that MnOx nanoparticles were strongly anchored to the surfaces of BiPO4rods when the mole ratio of Mn to Bi was controlled at a low level,forming MnOx/BiPO4heterojunctions with effective and sound interfaces.The MnOx/BiPO4heterojunctions exhibited higher photoactivity than pristine BiPO4for photodegradation of methyl blue under UV irradiation,which could be attributed to the efficient charge transfer at the heterojunction interfaces.The higher light absorption ability of MnOx/BiPO4in the range of300?420nm compared with pristine BiPO4was also responsible for the enhanced photocatalytic activities of MnOx/BiPO4heterojunctions.