Bi2O3 Nanoparticles Research Articles

Nontoxic Flexible Pvc Nanocomposites with Ta2o5 and Bi2o3 Nanoparticles for Shielding Diagnostic X-Rays

Nontoxic Flexible Pvc Nanocomposites with Ta2o5 and Bi2o3 Nanoparticles for Shielding Diagnostic X-Rays

Bi2O3 nanoparticles exhibit potent broad-spectrum antimicrobial activity and the ability to overcome Ag-, ciprofloxacin- and meropenem-resistance in P. aeruginosa: the next silver bullet of metal antimicrobials?

Antimicrobial resistance is a persistent threat to global public health. In order to combat the spread of pathogenic bacteria, numerous antimicrobial materials have been incorporated into wound dressings and medical devices such as implants and catheters. The most frequently utilized of these materials are Ag-salts and Ag-nanoparticles (AgNPs) due to their low minimum inhibitory concentrations (MICs) against common Gram-negative pathogenic bacteria such as P. aeruginosa. However, such Ag-based materials are limited to treating Gram-negative bacteria and prone to generating Ag-resistant phenotypes after only 7 consecutive exposures to these materials at a sub-inhibitory concentration. Here, we demonstrate α-Bi2O3 NPs as potential replacements for such materials, i.e., α-Bi2O3 NPs that exhibit potent broad-spectrum antibacterial activity (MIC = 0.75 μg mL-1 against P. aeruginosa; MIC = 2.5 μg mL-1 against S. aureus). Furthermore, these NPs are effective against Ag-resistant and carbapenem-resistant bacteria (MICs = 1.0 μg mL-1 and 1.25 μg mL-1, respectively) and also show a synergistic effect with meropenem (mero) in P. aeruginosa bacteria, allowing for the use of meropenem with smaller therapeutic doses (fractional inhibitory concentration = 0.45). Finally, unlike other materials that have been explored as effective antimicrobials, α-Bi2O3 NPs do not contribute to the development of Bi-resistant phenotypes after 30 passages of consecutive exposure to a sub-lethal dose of such NPs. Our results demonstrate that Bi-based materials represent a critical tool against multidrug resistant bacteria and require greater attention within the community. We anticipate this study to inspire broader investigation into the use of other metal oxides as antimicrobial materials, particularly those that limit the development of resistant phenotypes.

Photo-electrocatalytic methanol oxidation on Pd decorated BiOI nanoparticles in alkali

Photo-electrocatalytic methanol oxidation on Pd decorated BiOI nanoparticles in alkali

Role of pH in the hydrothermal synthesis of phase pure alpha Bi2O3 nanoparticles and its structural characterization

Phase pure bismite nanoparticles were successfully prepared by means of hydrothermal method by varying the precursor solution pH from 10 to 13. The as-prepared nanoparticles were characterized by different techniques such as X-ray diffraction pattern (XRD), Raman spectroscopy, Scanning electron microscopy (SEM) and Energy dispersive X-ray spectroscopy (EDX). The effects of pH on the structural properties of these nanoparticles were corroborated using XRD and Raman spectrum. From the XRD pattern it is found that all the samples are polycrystalline in nature and the Raman spectra are used to confirm the phase transformation of the Bi2O3 nanoparticles. At the low pH value, the SEM image reveals that as-prepared samples are homogeneous with particle size of ~ 25 nm and with the increase in the pH value spherical particle forms uniform blocks like morphology for both the samples prepared at the pH 12 and 13. Copyright © 2017 VBRI Press.

Cu2+-doped α–β phase heterojunctions in Bi2O3 nanoparticles for enhanced photocatalytic degradation of organic dye rhodamine B

Cu2+-doped α–β phase heterojunctions in Bi2O3 nanoparticles for enhanced photocatalytic degradation of organic dye rhodamine B

A comprehensive Monte Carlo study to design a novel multi-nanoparticle loaded nanocomposites for augmentation of attenuation coefficient in the energy range of diagnostic X-rays

Abstract Introduction: The present study aimed to investigate the radiation protection properties of silicon-based composites doped with nano-sized Bi2O3, PbO, Sm2O3, Gd2O3, WO3, and IrO2 particles. Radiation shielding properties of Sm2O3 and IrO2 nanoparticles were investigated for the first time in the current study. Material and methods: The MCNPX (2.7.0) Monte Carlo code was utilized to calculate the linear attenuation coefficients of single and multi-nano structured composites over the X-ray energy range of 10–140 keV. Homogenous distribution of spherical nanoparticles with a diameter of 100 nm in a silicon rubber matrix was simulated. The narrow beam geometry was used to calculate the photon flux after attenuation by designed nanocomposites. Results: Based on results obtained for single nanoparticle composites, three combinations of different nano-sized fillers Sm2O3+WO3+Bi2O3, Gd2O3+WO3+Bi2O3, and Sm2O3+WO3+PbO were selected, and their shielding properties were estimated. In the energy range of 20-60 keV Sm2O3 and Gd2O3 nanoparticles, in 70-100 keV energy range WO3 and for photons energy higher than 90 keV, PbO and Bi2O3 nanoparticles showed higher attenuation. Despite its higher density, IrO2 had lower attenuation compared to other nanocomposites. The results showed that the nanocomposite containing Sm2O3, WO3, and Bi2O3 nanoparticles provided better shielding among the studied samples. Conclusions: All studied multi-nanoparticle nanocomposites provided optimum shielding properties and almost 8% higher attenuation relative to single nano-based composites over a wide range of photon energy used in diagnostic radiology. Application of these new composites is recommended in radiation protection. Further experimental studies are suggested to validate our findings.

Production of nanopowders of bismuth oxide doped with silver by pulsed electron beam evaporation in vacuum

Various bismuth containing compounds are promising in many applications, including for creating photocatalysts based on them using a visible range of light. However, strong polymorphism (9 polymophic phases of Bi2O3), thermal instability and changes in the properties of bismuth oxide during long-term storage significantly complicate work with it. One way to increase stability and improve photocatalytic properties is by doping Bi2O3 with various metals. Ag doped Bi2O3 nanoparticles (NPs) are typically produced using chemical techniques often associated with the presence of toxic chemicals. The present paper used an environmentally friendly method of producing NPs using the method of pulsed electron beam evaporation in vacuum. The evaporation target was obtained by solid phase synthesis in an electric furnace on air using silver nitrate additives (1 and 5 wt.%). Textural, thermal and magnetic properties of the obtained NPs have been studied. Was found that the Ag-Bi2O3 NPs have a specific surface area (SSA) of 23.7 m2/g, which was almost 2 times bigger than the SSA of the pure Bi2O3 (13.2 m2/g) obtained previously. The thermal stability of the Ag-doped Bi2O3 samples was maintained to the temperature 350°C. While further heating on air took place the phase transition β → α

Understanding the Effect of Introducing Micro- and Nanoparticle Bismuth Oxide (Bi2O3) on the Gamma Ray Shielding Performance of Novel Concrete.

The aim of this study is to investigate the radiation shielding properties of novel concrete samples with bulk Bi2O3 and Bi2O3 nanoparticles (Bi2O3 NP) incorporated into its composition. The mass attenuation coefficient of the concrete samples without Bi2O3 and with 5 and 7 wt% bulk Bi2O3 were experimentally determined and were compared against values obtained using the XCOM and Geant4 simulations. Both methods greatly agree with the experimental values. The linear attenuation coefficients (LAC) of blank concrete (C-0), concrete with 5% bulk Bi2O3 (C-B5), and concrete with 5% nanoparticle Bi2O3 (C-N5) were determined and compared at a wide energy range. We found that the LAC follows the trend of C-0 < C-B5 < C-N5 at all the tested energies. Since both C-B5 and C-N5 have a greater LAC than C-0, these results indicate that the addition of Bi2O3 improves the shielding ability of the concretes. In addition, we investigated the influence of nanoparticle Bi2O3 on the LAC of the concretes. The half-value layer (HVL) for the concretes with bulk Bi2O3 and Bi2O3 nanoparticles is also investigated. At all energies, the C-0 has the greatest HVL, while C-N15 has the least. Thus, C-N15 concrete is the most space efficient, while C-0 is the least space efficient. The radiation protection efficiency (RPE) of the prepared concretes was found to decrease with increasing energy for all five samples. For C-0, the RPE decreased from 63.3% at 0.060 MeV to 13.48% at 1.408 MeV, while for C-N15, the RPE decreased from 87.9 to 15.09% for the same respective energies. Additionally, C-N5 had a greater RPE than C-B5, this result demonstrates that Bi2O3 NP are more efficient at shielding radiation than bulk Bi2O3.

Structural, optical, electrochemical and electrical studies of Bi2O3@rGO nanocomposite

Bismuth oxide incorporated reduced graphene oxide (Bi2O3@rGO) nanocomposite containing different bismuth nitrate Bi(NO3)3 concentrations were synthesized via facile in-situ chemical reduction technique. The SEM image of Bi2O3@rGO nanocomposite revealed a flower-shaped morphology with Bi2O3 nanoparticles over rGO sheets with an average particle size ranging within 103 nm–326 nm. The crystallite size of Bi2O3@rGO nanocomposite varied from 10.42 nm to 25.62 nm with the increasing amount of Bi(NO3)3 content into it. The vibration signatures of Bi–O, Bi–O–Bi, C–O, CC, CO, C–H2, and O–H bonds were obtained at 446 cm−1, 846 cm−1, 1034 cm−1, 1558 cm−1, 1729 cm−1, 2901 cm−1 and (3205–3261) cm−1 respectively from the FTIR analysis of Bi2O3@rGO nanocomposite. The bandgap of Bi2O3@rGO nanocomposite decreased from 3.63 eV to 2.32 eV with the variation of Bi(NO3)3 content from 5 mM to 25 mM respectively. The atomic percentage of O (1s), N (1s), C (1s), Bi (4d), Bi (4f) and Bi (5d) were varied as 13.64–13.06 at.%, 1.81–1.22 at.%, 64.46–43.14 at.%, 12.96–27.72 at.%, 3.59–7.35 at.% and 3.55–7.51 at.% respectively with increasing the Bi(NO3)3 conc. from 5 mM to 25 mM. The maximum specific capacitances of 690.88 F/g and 1248.355 F/g were exhibited by 25 mM Bi2O3@rGO nanocomposite at 5 mV/s scan rate and 1 A/g current density respectively, also besides achieving the highest Ecorr value of 0.107 V from the corrosion analysis. Moreover, I–V characteristics for Bi2O3@rGO nanocomposites exhibit diode characteristic curves.

Controlled micro/mesoporous carbon aerogel structure as a template for Bi2O3 nano-particles/rods to improve the performance of asymmetric supercapacitors

Metal oxides combined with porous carbon nanostructures as the active substance in supercapacitor electrodes have been considered by many researchers. In this study, the electrochemical performance of metal oxide nanoparticles and nanorods for application in supercapacitors has been studied. Bi2O3 nanoparticles and nanorods with carbon aerogel (CA) template are combined in a nanocomposite structure via one-pot synthesis technique. Regarding the high surface area (686 m2 g−1), this nanocomposite showed a good electrochemical performance and the corresponding electrode achieved an specific capacity of 1193 F g−1 at 1 A g−1 current density in a 3-electrode system while the specific capacity of CA-Bi2O3 electrodes were 135 F g−1 and 672 F g−1, respectively at the same current density. Moreover, in the pr-Bi2O3-CA electrode, the capacity was reduced 5.3% by 6000 cycles showing cyclic stability due to fast charge transfer during the electrochemical process. A cell has been fabricated using pr-Bi2O3-CA and CNF electrodes resulting in a high performance supercapacitor with 15975 W kg−1 and 44.45 Wh kg−1 specific power and specific energy, respectively. The performance of this supercapacitor is much higher than general capacitors and close to NI-MH batteries. Red Light-Emitting Diode (LED) is also lit successfully by two supercapacitors in series. Based on the results, the suitable electrochemical efficiency of pr-Bi2O3-CA electrode approves a promising alternative for energy storage.

A High-Sensitivity Flexible Direct X-ray Detector Based on Bi2O3/PDMS Nanocomposite Thin Film.

The characteristics of mechanical flexibility, low health risk, and simple processing of polymer nanocomposite materials make them potentially applicable as flexible X-ray detectors. In this study, we report on a high sensitivity, environmentally friendly, and flexible direct X-ray detector using polymer nanocomposite material consisting of bismuth oxide (Bi2O3) nanoparticles and polydimethylsiloxane (PDMS). This detector was realized by printing patterned Ag electrodes on the polymer nanocomposite material. The response of PDMS to X-rays was verified for the first time, and the effect of doping different contents of Bi2O3 nanoparticles on the performance of the device was tested. The optoelectronic performance of the optimized detector indicated a high sensitivity (203.58 μC Gyair−1 cm−2) to low dose rate (23.90 μGyair s−1) at a 150 V bias voltage and the X-ray current density (JX-ray) was 10,000-fold higher than the dark current density (Jdark). The flexible direct X-ray detector could be curled for 10,000 cycles with slight performance degradation. The device exhibited outstanding stability after storage for over one month in air. Finally, this device provides new guidance for the design of high-performance flexible direct X-ray detectors.

Visible-light sensitization and recombination delay through coupling CaFe2O4 on Bi2O3 nanocomposite for high performance photocatalytic and antibacterial applications

The development of Bi2O3 based advanced photocatalytic materials has seen a momentous leap in recent decades. However, pure Bi2O3 suffers rapid e−/h+ pair recombination rate and low visible light response. To improve its photocatalytic performance, CaFe2O4-Bi2O3 nano-heterojunction was constructed using ultrasonic assisted chemical co-precipitation method. The morphological analysis depicted the decoration of spherical CaFe2O4 on sheet-like Bi2O3 nanoparticles (NPs) surface. The interface in nanocomposites (NCs) promotes migration of charge carriers and improves its life time that was verified using photoluminescence study. The elemental composition of NCs was verified using XPS and EDAX. The photon absorption ability of NCs in visible region was favored by the energy bandgap of 2.16 eV. The NCs exhibited 8 to 16 fold increase in kinetic rate constant than Bi2O3 and CaFe2O4 for the methylene blue (MB) dye degradation. The dominant reactive oxygen species (ROS) in photodegradation process was found to be hydroxyl radicals (OH.). The NCs was magnetically recoverable with high reusable capacity. The multifunctionality of NCs as antibacterial agents was also investigated. The NCs greatly inhibited the growth of Escherichia coli and Bacillus subtilis. The current investigation provides a promising approach for photodegradation and bacterial inactivation by improved performance of CaFe2O4-Bi2O3 NCs.

Synthesis and characterization of Bi2O3 NPS and photocatalytic application with methylene blue

Bismuth oxide nanoparticle was synthesized by Hydrothermal method, with two different molar ratio of precipitating agent of NaOH which decided the variations of two samples (1:5) and (1:6) was added to observe its effect on structural, optical and photocatalytic behaviour. So the prepared bismuth oxide nano particle was characterized by X-ray Diffractometer to study about its crystalline properties. The crystal size was observed as 30.7 and 42.84 nm, The optical properties were characterized by using UV-Vis spectrometer and its band gap value was calculated as 2.74 eV and 2.42 eV respectively. Morphological studies were obtained by using scanning electron microscopy and the elemental X-ray analysis confirmed the proportions of Bi2O3 nanoparticles of two samples (1:5) and (1:6). FTIR Spectrometer studies explained the condensation of OH group accompanied by the formation of Bi2O3 which is strongly dependent on the pH of reaction. A lattice change was observed, symmetric and asymmetric bonds were analysed by using FTIR spectrometer. The binding energy and its energy level were analysed by using X-ray Photo electron Spectroscopy and its value was 292 and 534 eV, and also the hydrothermal synthesised Bi2O3 NPs was used to analysed the photocatalytic degradation of Methylene blue under the irradiation of LED white light.

The impact of alkaline earth oxides on Bi2O3 and their catalytic activities in photodegradation of Bisphenol A.

The BPA into wastewater has posed a threat to environment and human health. Hence, we aimed to eliminate BPA in a short time and with a rapid degradation rate from food wastewater. Herein, the effects of different alkaline-earth oxide doped with Bi2O3 nanoparticles on the photocatalytic degradation of bisphenol A were investigated. SrO-Bi2O3, CaO-Bi2O3, and MgO-Bi2O3 binary oxides were prepared by wet-impregnation method. The structural and optical features of catalysts were clarified BET, XRD, DRS, FT-IR, PL, and SEM techniques. The photocatalytic activities of catalysts were compared for different light sources. Considering that the characterization analysis and experimental results, the highly improved photocatalytic activity was mainly attributed to the effective structure of the SrO-Bi2O3 binary oxide and the strong alkali properties in the nanocomposite. Obviously, 5wt% SrO-Bi2O3 photocatalyst showed more excellent degradation performance and highest degradation reaction rate (0.21 mg l–1 min–1) within 30 min. It was observed that the photocatalytic activity improved by the additive of alkaline oxide on Bi2O3.

Facile preparation of commercial Bi2O3 nanoparticle decorated activated carbon for pseudocapacitive supercapacitor applications

In this work, a facile method to prepare Bi2O3 decorated activated carbon (Bi2O3@AC) composites with high pseudocapacitive properties was presented. The inorganic–organic composites synthesized using commercial Bi2O3 and active carbon with different weight ratio. The composites were assessed using spectroscopic, microscopic, and diffractive techniques. Our assessments confirmed that active carbons were successfully doped with commercial Bi2O3 nanoparticles with different dopant rates. The electrochemical performance of as-prepared materials was researched by cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy in 6 M KOH electrolyte. Higher specific capacitance was achieved for increased Bi2O3 nanoparticle in composites. The 20%-Bi2O3@AC had a maximum specific capacitance of 565 F/g at a current density of 1 A/g. In addition, the symmetrically assembled supercapacitor delivers a high energy density (23.0 Wh kg−1). Moreover, 67% of the initial capacitance is maintained after 1500 cycles at 200 mV/s, suggesting good cycling stability. Due to the synergistic effect of compositing a promising electrochemical performance was observed that was not obtained by bare AC or Bi2O3. As a result, the electrochemical properties of 20%-Bi2O3@AC composite is promising and it may be used as potential electrode for supercapacitor.

Controlling the structure and photocatalytic properties of three—dimensional aerogels obtained by simultaneous reduction and self-assembly of BiOI/GO aqueous colloidal dispersions

Water pollution affects all living habitats, since it is the most basic element that sustains all life forms and, as an exceptional solvent, it readily makes any compound available for living cells, either nutrients or noxious substances. Elimination of molecular contaminants from water quality is one of the most challenging technical problems that conventional treatments like flocculation and filtration fail short to defeat. Particulate photocatalysts, used to degrade contaminants, have the main drawback of their recovery from the water matrices. The inclusion of photocatalytic nanoparticles (NPs) into a large supporting framework, is presented as an innovative approach aiming to ensure a facile separation from water. To this end, three-dimensional (3D) aerogels with photocatalytic properties were prepared by a simple and scalable method based on the reduction—induced self-assembly of graphene oxide (GO) in the presence of BiOI nanoparticles. With the help of ascorbic acid, as a green reducing agent, partial reduction of GO into reduced graphene oxide (RGO) and self-assembly of both kinds of nanostructures into a porous monolith was achieved. BiOI doped RGO aerogels were further stabilized and morphologically controlled using poly (ethylene glycol) as stabilizer. The photocatalytic performance of these aerogels was evaluated by following the discoloration of methylene blue (MB) solution, under visible light irradiation, showing that structure and dispersion degree of NPs to be fundamental variables. Hence, this methodology is proposed to produce hybrid aerogels with controlled morphology and photocatalytic performance that has the potential to be used in water cleaning procedures.

Effect of bulk and nanoparticle Bi2O3 on attenuation capability of radiation shielding glass

The aim of this study is to examine the effect of Bi2O3 concentration and particle size on Bi2O3 glass. The tested glasses had the composition of SiO2–Bi2O3–CaO–MgO–B2O3–K2O–Na2O–ZnO. Ordinary glass was compared with glasses with 10% Bulk Bi2O3, 10% Bi2O3 Nanoparticles (NPs), 20% Bulk Bi2O3, and 20% Bi2O3 nanoparticles. The mass attenuation coefficients (MACs) of all the investigated glasses were determined between 0.0595 MeV and 1.41 MeV. The results demonstrated that increasing the Bi2O3 content in the glass matrix improved their shielding capability, as well as showing that the NPs provided greater attenuation than the bulk Bi2O3 at the same concentration. The percent increase in the MAC between the bulk and nano Bi2O3 was also calculated and analyzed. From the MAC values, the LAC of the glass was determined and similar results were found compared to the MAC figure. The HVL and MFP of the glass were then analyzed and the results demonstrated that the glass with Bi2O3 NPs attenuated the same amount of photons at a smaller thickness, making the NP shield more effective. The heaviness of the samples illustrated that all the tested samples have a smaller weight than pure lead, making them more desirable. The attenuation factor of the glass (Att. Factor %) showed that increasing the Bi2O3 content in the samples and increasing the thickness of the shields both improve the shielding capability of the glass. Lastly, the dlead of the glasses was determined, indicating that the greatest reduction in thickness occurs near the K-absorption edge of bismuth. Overall, the glass with 20% Bi2O3 NPs demonstrated to have the greatest potential for radiation shielding applications.

Evaluation of the effects of bismuth oxide (Bi2O3) micro and nanoparticles on the mechanical, microstructural and γ-ray/neutron shielding properties of Portland cement pastes

This study presents a comparison of the effects of micro-Bi2O3 and nano-Bi2O3 powders on the mechanical, microstructural and gamma / neutron shielding properties of Portland cement pastes. Cement pastes with various ratios of cement (up to 30 wt-%) replaced with Bi2O3 micro and nanoparticles were prepared. Consistency, compressive strength, water accessible porosity and mercury intrusion porosimetry tests were performed, in order to characterize their engineering properties. In addition, experimental and theoretical evaluations of γ-ray and neutron shielding properties were performed. The results showed that the incorporation of Bi2O3 powders gradually leads to a decline in cement pastes’ compressive strength and an increase in their porosity, as the amount of powder is increased. However, the deterioration rate varies depending of type of powder used, in favor of nano-Bi2O3. Gamma attenuation tests results indicate that the addition of Bi2O3 powders enhances the shielding capability of pastes, in the energy range of interest (0.08–2.614 MeV). However, the effects of particle size on γ-ray attenuation are negligible in that energy range. Slow neutron attenuation study showed that the addition of nano-Bi2O3 improved the shielding ability of cement pastes, with enhancements ranging between 15.3% and 25.5% for samples with 5 and 30 wt-% nano-Bi2O3, respectively. In conclusion, this study shows that the addition of nano or micro-Bi2O3 is effective in producing lead-free cementitious composites with improved γ-ray and neutron shielding properties. Unlike gamma shielding, nano-sized Bi2O3 has a better ability to attenuate neutrons, in comparison to their micro-sized counterparts.

Preparation of Bismuth Oxide Nanoparticles/PSi/Si hetrojunction by simple chemical method for solar cell applications

This work shows the fabrication of Bi2O3/PSi heterojunction for solar cell applications prepared by simple chemical method. Bi2O3 nanoparticles were deposited on the n-type porous silicon and glass substrates by drop casting method. The structural and optical properties of bismuth oxide thin film were studied by XRD, SEM, UV-VIS and FTIR analysise. XRD investigation showed that the thin film is polycrystalline and the optical properties stated that bismuth oxide thin film has direct optical band gap of 2.5 eV in addition to the study of I-V in dark and under illumination and finally. The results indicate a significant improvement in the properties of porous silicon, and thus an increase in the conversion efficiency, as the calculated efficiency values for (Al/Bi2O3/PSi/Si/Ag) heterojunction.

Optimization of phosphor concentration of surface‐modified Bi2O3 nanoparticle‐loaded plastic scintillators for high‐energy photon detection

In this study, the 3-phenylpropionic acid (3-PPA)-modified Bi2O3 nanoparticle-loaded plastic scintillators were synthesized to obtain fast scintillators having high detection efficiency of high-energy X-rays. To reach a high light yield, the content of 2-(4-tert-butylphenyl)-5-(4-phenylphenyl))-1,3,4-oxadiazole (b-PBD) in the plastic scintillators was optimized. The detection efficiency for high-energy photons was enhanced by the incorporation of surface-modified Bi2O3 nanoparticles of less than 10 nm into scintillators at 5 or 10 wt%. In the pulse-height spectra, the photoelectric peak positions were located at the highest channels for the samples containing 0.50 or 1.0 mol% b-PBD regardless of the Bi concentration. The photoelectric peak positions shifted to lower channels with a further increase in the b-PBD concentration, which indicates that the light yield decreased due to concentration quenching. In addition, the time resolution of the detector equipped with the studied samples was of the sub-nanosecond scale, suggesting that they had a very fast response.