Template-Free Hydrothermal Synthesis Different Morphologies of Visible-Light-Driven BiVO<SUB>4</SUB> Photocatalysts

Abstract

Monoclinic BiVO4 nano- and microstructures with a diversity of well-defined morphologies, such as nanoplates, dendrite leaves-like structures, sub-microrods, and microflowers were synthesized via a template-free hydrothermal process with bismuth nitrate and ammonium metavanadate as metal source. The crystal structures, morphologies and optical properties of the as-prepared samples were characterized by X-ray powder diffraction (XRD), transmission electron microscope (TEM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and UV-visible absorption spectra (UV-vis). Results showed that the pH value of the solution and the volume of ethylenediamine have great effect on the formation of these unique structures. The photocatalytic activity of these as-prepared samples had been tested by degradation of methylene blue under visible light, indicating that showed good photocatalytic performance.

BiVO4 Microspheres Coated with Nanometer-Thick Porous TiO2 Shells for Photocatalytic Water Treatment under Visible-Light Irradiation

“…21-1272) were also included as references. It can be seen that both BiVO 4 -L and BiVO 4 -S showed the same diffraction peaks at 18.8, 19.0, 28.8, 30.6, 34.6, 34.8, 39.7, 42.5, 47.0, 47.3, 50.3, 55.3, 59.1, and 59.6°, ascribed to the (100), (011), (121), (040), (200), (002), (211), (051), (240), (042), (202), (161), (321), and (123) planes of the monoclinic scheelite phase, respectively. , These results clearly confirm that the synthesized cores show the monoclinic scheelite crystalline structure, which is the most photoactive phase of BiVO 4 , as we prefer. Compared to the BiVO 4 microspheres, the BiVO 4 @TiO 2 -L and BiVO 4 @TiO 2 -S microspheres showed additional diffraction peaks at 25.1 and 37.3°, which are indexed to the (101) and (112) planes of the anatase TiO 2 , suggesting that the porous TiO 2 shell synthesized herein is of the anatase phase, which shows the highest photoactivity among the three types of TiO 2 .…”

Photocatalytic Removal of Organics over BiVO4-Based Photocatalysts

“…For example, the hydrothermal method is widely used to prepare m-BiVO 4 with different morphologies because the morphology of the final product obtained via such a process can be easily controlled by changing the reaction conditions, such as reaction temperature, reaction time, solution pH, and concentration [6]. Recently, different morphologies (such as nanospheres, nanorods, nanoflowers, nanosheets, nanotubes, hyperbrached) of monoclinically structured BiVO 4 crystallites have been synthesized by the hydrothermal method with the assistance of surfactants and pH-controlling additives [28].…”