Facile combustion synthesis of highly active Mo doped BiVO4 for photocatalytic dye degradation, photo-oxidation of alcohols, antifungal and antioxidant activities (original) (raw)
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Bismuth vanadate, an agile photocatalyst for the degradation of malachite green dye
2019
Visible light-active bismuth vanadate (BiVO4) nanoflakes were successfully synthesized by coprecipitation technique. As prepared BiVO4 was characterized by X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). Monoclinic forms of BiVO4 having average size of 37.76 nm were obtained. V-O, Bi-O and VO4 groups were observed by FTIR. The elemental mapping image showed 49.25% Bi, 9.69% V and 41.06% O which were found to be distributed homogeneously. As prepared BiVO4 was applied in the photocatalytic degradation of malachite green dye (MG). The maximum degradation was found to be 72.72% in 120 min using 500 W halogen lamp irradiation which may be due to the synergistic effect of lamp light and a stream of air. The optimum catalyst dose was found to be 0.1 g per 100 mL of 10 ppm dye concentration with the initial pH being 6.
A Facile Synthesis and Properties of Bismuth Vanadate (BiVO4) Photocatalyst by Hydrothermal Method
IOP Conference Series: Materials Science and Engineering, 2019
In this study, BiVO 4 photocatalysts were synthesized by hydrothermal method using Bi(NO 3) 3• 5H 2 O and NH 4 VO 3 as raw materials followed by calcination at different temperatures in the range from 350 o C to 600 o C. The as-synthesized BiVO 4 samples were characterized by a number of physicochemical techniques including X-ray diffraction (XRD), Raman analysis, Scanning Electron Microscopy (SEM), and UV-Visible (UV-Vis) light diffuse reflectance spectrophotometry. The effect of temperatures calcination on structure, surface morphology, visible-light photocatalytic activity and light absorption performance of BiVO 4 was discussed in details.
Materials Science and Engineering: B, 2019
Herein, we report the one pot template-free synthesis of novel monoclinic Bismuth vanadate (m-BiVO 4) nanoparticles, with highly dispersive nature and uniform size of 50-70 nm were fabricated by the facile hydrothermal method, for efficient visible light photocatalytic degradation of toxic organic dyes (Rhodamine-B and Crystal violet). For phase, composition and chemical purity, of the as-synthesized nanoparticles were characterized by using X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDX). To elucidate the morphology and topography, scanning electron microscopy (SEM) and transmission electron microscope (TEM) techniques were used. For the ascription of functional groups, Fourier transforms infrared spectroscopy (FTIR) was employed. The surface area of the as-synthesized nanoparticles was analyzed using Brunauer−Emmett−Teller (BET) and found to be 24.946 m 2 /g and pore diameter 1.932 nm; m-BiVO 4 nanoparticles showed enhance photocatalytic response for the degradation for both dyes under visible light. PL study indicates the promised ability of the m-BiVO 4 nanoparticle for visible light devices.
Nanomaterials
Bismuth vanadate (BiVO4) is one of the best bismuth-based semiconducting materials because of its narrow band gap energy, good visible light absorption, unique physical and chemical characteristics, and non-toxic nature. In addition, BiVO4 with different morphologies has been synthesized and exhibited excellent visible light photocatalytic efficiency in the degradation of various organic pollutants, including volatile organic compounds (VOCs). Nevertheless, the commercial scale utilization of BiVO4 is significantly limited because of the poor separation (faster recombination rate) and transport ability of photogenerated electron–hole pairs. So, engineering/modifications of BiVO4 materials are performed to enhance their structural, electronic, and morphological properties. Thus, this review article aims to provide a critical overview of advanced oxidation processes (AOPs), various semiconducting nanomaterials, BiVO4 synthesis methodologies, engineering of BiVO4 properties through mak...
Journal of the Brazilian Chemical Society
The bismuth vanadate (BiVO4) is a semiconductor that has attracted much attention due to the photocatalytic efficiency in the visible light region. The objective of this work was to synthesize monoclinic BiVO4 by solution combustion synthesis, with different surfactants and fuels and apply it as photoelectrodes. The characterization by infrared spectroscopy and Raman spectroscopy showed that all samples showed characteristic bands of the monoclinic structure BiVO4. The samples synthesized with glycine and glycine/Tween (R) 80 had V2O5. The film obtained from the alanine/Tween (R) 80 showed highest photocurrent values, which may be related to smaller size particles (200 to 300 nm) observed by scanning electron microscopy images. The films obtained using alanine showed highest values of rate constant reaction and percentage discoloration of methylene blue.
Effect of sulfur doping on the photocatalytic performance of BiVO4 under visible light illumination
Chinese Journal of Catalysis, 2013
Porous monoclinic bismuth vanadate (BiVO4 ) and sulfur-doped bismuth vanadates (BiVO4 S0.05, BiVO4 S0.08, and BiVO4 S0.12) were synthesized by a dodecylamine-assisted alcohol-hydrothermal route in the absence and presence of thiourea or Na2S. The physicochemical properties of the materials were characterized and their photocatalytic performance for the degradation of methylene blue and formaldehyde under visible light was evaluated. The samples have a single phase monoclinic scheetlite crystal structure with a porous olive-like morphology, surface areas of 8.4-12.5 m 2 /g, and bandgap energies of 2.40-2.48 eV. Surface Bi 5+ , Bi 3+ , V 5+ , and V 4+ species were present on the S-doped BiVO4 samples. Sulfur doping influenced the surface Bi 5+ /Bi 3+ , V 5+ /V 4+ , and Oads/Olatt molar ratios, and the amount of sulfur doped had an important effect on the photocatalytic performance. Under visible light, BiVO4 S0.08 performed the best in the photodegradation of methylene blue and formaldehyde. A higher surface oxygen species concentration and a lower bandgap energy were responsible for the excellent visible light photocatalytic performance of BiVO4 S0.08.
Nanostructured bismuth vanadate (BiVO 4 ) thin films for efficient visible light photocatalysis
Successful strategies on combining the versatility of mechanochemical synthesis with rf-sputtering technique were developed for the controllable deposition of non-toxic and stable monoclinic BiVO4 thin films, which has a relatively narrow band gap (z2.4 eV) that allows a direct photoactivation under visible light. The coupled deposition approach enables the stabilization of single phase, high-quality monoclinic BiVO4 thin films, deposited using sintered target made with nano-powders produced from mechanochemical process. Investigations of structural, vibrational, morphological and optical properties were carried out using HT-XRD, XRD, Raman, AFM, FE-SEM and UV-Visible absorption techniques. Monoclinic scheelite phase of BiVO4 was studied with different morphologies and textures of thin film surfaces including the occurrence of organized nano-islands (20-50 nm) under defined deposition pa- rameters. The sputtered BiVO4 films display an electronic band gap of 2.5 eV, which is suitable for harvesting visible light radiation. Photocatalytic (PC) experiments were performed with selected textured BiVO4 thin films for the degradation of rhodamine 6G (Rh6G) dyes under visible light irradi- ation. Different PC efficiencies were obtained and the results were interpreted based on the thin film morphologies and surface characteristics.
Applied Physics A, 2020
Highly crystalline bismuth vanadate (BiVO 4 ) powder was prepared by a template-free hydrothermal method under different pH (~ 2, 3, 5, 8, 11) reaction conditions and characterized by X-ray diffraction, scanning electron microscopy, Raman spectroscopy, Brunauer-Emmett-Teller surface area, photoluminescence, and electron spin resonance techniques. It was found that variation in pH of the precursor solution can influence morphology, structure and, consequently, photocatalytic efficiency of obtained products. The spherical BiVO 4 nanoparticles were obtained at pH 2 and 3, nanorods at pH 5 and 8, whereas nanoplates were obtained at pH 11. Among the different pH-based BiVO 4 samples, the one prepared at pH ~ 11 (BiVO 4 -11) exhibited surface area 102.74 m 2 /g and degraded the dye solution completely within 90 min. Therefore, pHcontrolled hydrothermal reaction can be useful to synthesize nanostructures with different morphologies efficiently for the enhanced photocatalytic degradation of pollutant under visible light.
A series of M-BiVO 4 (M = Ag, Co, and Ni) particles were successfully prepared by amorphous heteronuclear complex precursor. The particles were characterized using X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), UV-vis diffuse reflectance spectroscopy and Raman spectra. The results showed that the crystallized M-BiVO 4 had a monoclinic phase with the hybrid metals, namely Co and Ni being attached on BiVO 4 particles in the form of oxides mainly. The M-BiVO 4 photocatalysts were responsive to visible light. Photodegradation of both methyl blue and 2,4-dichlorophenol over M-BiVO 4 composites was observed at wavelength >420 nm. Co-BiVO 4 exhibited the best photocatalytic efficiency, with a decoloration percent of about 85% after 2-h irradiation (at > 420 nm). Nearly 90% of 2,4-dichlorophenol was removed in 5 h. Electron paramagnetic resonance (EPR) study confirmed that superoxide and hydroxide radicals were formed under light irradiation and might be responsible for the degradation of the organic compound.