Ball-milling synthesized Bi2VO5.5 for piezo-photocatalytic assessment

The mechanochemical ball milling followed by heating at 650 °C for 5 h successfully produced the single-phase Bi₂VO_5.5 powder. Catalytic activity for methylene blue dye degradation was investigated. Raman spectroscopy and X-ray diffraction were used to confirm the phase formation. The sample's charge carrier transportation behavior was ascertained using time-dependent photocurrent analysis. The piezo-photocatalysis experiment yielded a 63% degradation efficiency for the ball-milled Bi₂VO_5.5 sample. The pseudo-first-order kinetics of the piezo-photocatalytic dye degradation are discerned, and the significant k value of 0.00529 min^-1 is achieved. The scavenger test declares the h⁺ radical is the predominant active species during the piezo-photocatalysis experiment. Vigna radiata seeds were used in a phytotoxicity test to evaluate the germination index. The mechanochemical activation method facilitates reactions by lowering reaction temperature and time. The effect of improved piezo-photocatalytic efficiency on the ball-milled Bi₂VO_5.5 powder is an unexplored area, and we have attempted to investigate it. Here, ball-milled Bi₂VO_5.5 powder achieved improved dye degradation performance.

Mechanochemical Synthesis of Bi2VO5.5 for Improved Photocatalytic Dye Degradation

A single-phase Bi₂VO_5.5 powder is formed effectively through a mechanochemical ball milling approach at 650 °C in 5 h and its photocatalytic performance on methylene blue dye is explored. X-ray diffraction and Raman spectroscopy analytical instruments are utilized to confirm the phase formation. The evident presence of irregular-shaped grains is affirmed using a scanning electron microscope. To ascertain the chemical condition of the components present, the Bi₂VO_5.5 powdered sample undergo an X-Ray photoelectron spectroscopy investigation. The sample is analyzed using a time-dependent photocurrent to discern its charge carrier transportation behavior. A photocatalytic study using Bi₂VO_5.5 powder produced through the mechanochemical ball milling method has not been explored till now. The efficacy of the ball-milled Bi₂VO_5.5 powder to attain enhanced photocatalytic efficiency which hasn't been investigated till now, is explored. The ball-milled Bi₂VO_5.5 sample achieved 70% degradation efficiency when performing the photocatalysis investigation. The photocatalytic dye degradation discerns pseudo-first-order kinetics and achieves a notable k value of 0.00636 min^-1. The scavenger test indicates that h⁺ radicals are the prominent active species during the photocatalysis experiment. The germination index is determined by conducting a phytotoxicity test with the use of Vigna radiata seeds. Here ball-milled Bi₂VO_5.5 powder attains enhanced dye degradation efficiency.

Microwave hydrothermal synthesis and upconversion properties of BiVO4 nanoparticles

Nanomaterials are the subject of extensive investigations due to their applications in medicine, multimodal imaging, volumetric displays, and photonics. Here, lanthanide-doped bismuth vanadate (BiVO₄) upconverting nanoparticles (UCNPs) have been reported. The nanoparticles have been synthesized by a microwave hydrothermal method. As-synthesized nanoparticles are highly crystalline in the tetragonal zircon phase with particles about 200 nm in size. Under 980 nm excitation, intense multicolor visible and near-infrared upconversion emissions are observed. Moreover, broadband infrared downshifting emissions are also observed. Time-resolved emission measurements have been carried out to investigate the involved upconversion and energy transfer mechanism. The BiVO₄-based UCNPs may provide a new class of nanomaterials for multifunctional applications.

A composite of platelet-like orientated BiVO4 fused with MIL-125(Ti): Synthesis and characterization

The development of heterojunctions is the current focus of the scientific community as these materials are visible light active and the staggered positioning of their band edges combats electron-hole recombination which is the downside of most photocatalysts. In this work, a two- step hydrothermal synthesis protocol was utilized to fabricate a novel observable-light active material, composed of platelet-like BiVO4 and a titanium-based metal organic framework (MOF) called MIL-125(Ti). The tuning of specific morphologies, such as platelet-like in BiVO4, provides the exposure of most reactive facets which are more reactive towards photooxidation of organics in water, thus increasing their efficiency. The as-synthesized heterojunction was characterized by Transmission electron microscopy (TEM), scanning transmission microscopy (SEM), X-Ray diffraction (XRD), Raman spectroscopy, ultraviolet-visible diffuse reflectance spectra (UV-Vis DRS), X-Ray photoelectron spectroscopy (XPS) and photoluminescence (PL) spectra. The formation of the heterojunction lead to a positive shift of the 3-2 Bi:Ti valence band (VB) (1.78 eV) when compared to 1.27 eV VB position of BiVO4. The PL and photoelectrochemical measurements revealed that the heterojunction photocatalyst designated 3-2 Bi-Ti demonstrated inhibited recombination rate (platelet-like BiVO4 > 3-2 Bi:Ti (PM) > MIL-125 > 1-1 Bi:Ti > 2-3 Bi:Ti > 3-2 Bi:Ti) and highly efficient interfacial charge shuttle between platelet-like BiVO4 and MIL-125(Ti) through the formed n-n junction.

Mechanochemically synthesized CuO/m-BiVO4 composite with enhanced photoelectrochemical and photocatalytic properties

Simultaneous enhancement on photon absorption and charge separation leads to improved photo-activities of a CuO/BiVO₄ composite over pristine BiVO₄.

Preparation, structure and luminescence properties of Ba2V2O7 microrods

Self-activated phosphor Ba₂V₂O₇ microrods were prepared by the hydrothermal reaction method.