A comparative study of photocatalytically active nanocrystalline tetragonal zyrcon-type and monoclinic scheelite-type bismuth vanadate

Abstract

Monoclinic scheelite-type BiVO4 is currently considered as one of the most promising non-titania photocatalysts, wheras tetragonal zircon-type BiVO4 is still poorly understood. Herein, a new and simple synthetic approach was applied and nanostructured single-phase zircon-type BiVO4 was successfully prepared by a controllable ethylene-glycol colloidal route. In addition, nanostructured monoclinic scheelite-type BiVO4 powders were also fabricated through annealing of the as-prepared samples. A comparative study of the two BiVO4 polymorphs was conducted and it turned out that the novel synthetic approach had a significant impact on porosity and photocatalytic performance of zircon-structured BiVO4. All the prepared materials, as-prepared and annealed, were meso-porous, while measured values of specific surface area of some zirconstructured samples (∼34 m 2 /g) were ∼7 times higher than those reported thus far for this phase. Interestingly, for the first time, zircon-type BiVO4, previously considered to be a poor photocatalyst, exhibited a better overall performance in degradation of methyl orange compared to monoclinic scheelite-type BiVO4. Hence, it could be expected that the here-presented synthesis and observations will both arouse interest in scarcely studied tetragonal zircon-type BiVO4 and facilitate as well as speed up further research of its properties.

Understanding the Structural-Dependent Photocatalytic Antibacterial Activity: a Case Study of Ag Modified BiVO4

“…The band gap energy of tz-BiVO 4 was estimated to be 2.59 eV, which is larger than that of 2.17 eV for ms-BiVO 4 (Fig. S7), being in accordance to previous reported results [ 13 , 29 ]. The anchoring of Ag cluster on BiVO 4 surfaces has no obvious consequences on the typical electronic transitions from O 2p to V 3d orbital, as illustrated by the UV-visible diffuse reflectance spectra of the as-prepared samples (Fig.…”

“…From solid state physics viewpoint, the photocatalytic performance is thought to be predominately regulated by the distortion of microstructure. The tetragonal zircon (tz-) BiVO 4 synthesized by ethylene-glycol colloidal path controllable at room temperature induces strongly improved photocatalytic activity over monoclinic scheelite (ms-) BiVO 4 , yet the underlying mechanism remains ambiguous [ 13 ]. Therefore, the modification of BiVO 4 is not limited to improving the photocatalytic activity; it is also absolutely necessary to explain the kinetics of photoinduced charge transfer from the microstructure.…”

Morphology-Controlled Synthesis of BiVO4 Materials and Their Ethanol Gas Sensing Properties

“…4). As shown, these BiVO 4 samples displayed the typical IV-type isotherms with hysteresis loops, which were the characteristics of mesoporous materials [28]. Moreover, their BET surface areas were 1.85, 1.97, 2.19, and 2.26 m 2…”

Fabrication and Characterization of a Novel Composite Magnetic Photocatalyst β-Bi2O3/BiVO4/MnxZn1−xFe2O4 for Rhodamine B Degradation under Visible Light

“…4 . Furthermore, there is high intensity reflection at 24.5 • in BV/MZF, which is caused by the conversion of monoclinic BiVO 4 to tetragonal BiVO 4 during the roasting process [25]. However, only the (440) characteristic diffraction peaks of MZF could be found in BV/MZF.…”