Bi2O3 Nanoparticles Research Articles

Production and characterization of flexible semiconducting polymer-nanoparticle composites for x-ray sensors

Fabrication and characterization of flexible semiconducting polymer-nanoparticles composite membranes for x-ray sensor device applications are presented in this work. Poly(vinyl alcohol) (PVA) polymer was initially doped with glycerol ionic liquid (IL) that permitted the control of its electrical resistivity. Metal-oxide Bi2O3 nanoparticles were prepared by a modified sol-gel method. The average nanoparticle size was found to be 39 ± 10 nm. Thin films of flexible polymer membranes with different nanoparticle concentrations were prepared using a solution casting method. Compositional characterizations revealed the formation of homogeneous polymer-nanoparticle membranes. Electrical impedance measurements of the membranes were performed for the membranes in a form of capacitor structure as a function of temperature and nanoparticle concentration. The measurements demonstrated that the membranes could be modeled with a pair of parallel resistor and capacitor that were assigned to the contributions of grain boundaries as well as the region of electron depletion in the membrane. As nanoparticle concentration increases, the resistivity and activation energy decrease. Current-voltage measurements demonstrated that the produced membranes function as x-ray sensors, and their response increases as a function of nanoparticle concentration. The produced membranes exhibit semiconducting properties that qualify them as potential candidates for device applications in the field of x-ray dosimeter.

Preparation of Ce3+ doped Bi2O3 hollow needle-shape with enhanced visible-light photocatalytic activity

Ce3+ doped Bi2O3 hollow needle-shape with enhanced visible-light photocatalytic activity was successfully prepared via the method of chemical precipitation using Bi(NO3)·5H2O and Ce(NO3)3·6H2O as the source of bismuth and cerium, HNO3 as solvent and NaOH as precipitants, respectively and after calcination at 500 °C for 2 h. The morphology and elemental composition, crystal form, purity and specific surface area of the hollow needle Bi2O3 were characterized by SEM-EDS, XRD, BET and FT-IR. The photocatalytic properties of the as-obtained samples were measured by UV-vis diffuse reflection spectroscopy and photochemical reactor. As a result, the obtained Bi2O3 hollow needle-shape doped with 5 wt% Ce shows good morphology, α-phase, stronger absorbent for visible light and good photocatalytic property. Under the simulated visible light of 300 W, the photodegradation rate of tetracycline over HNB-Ce can reach to 89.1%, which is higher than that of commercial Bi2O3 nanoparticles and Bi2O3 hollow needle-shape.

Facile synthesis of well-dispersed Bi2O3 nanoparticles and rGO as negative electrode for supercapacitor

Bi2O3 nanoparticles coupled with reduced graphene oxide (rGO) nanostructure were synthesized through liquid-phase precipitation and calcination method, and their supercapacitor properties were studied as negative electrode materials. The as-prepared Bi2O3/rGO achieved a maximum specific capacitance of 1423 F g−1 at a current density of 1 A g−1, excellent electrochemical stability (capacity retention of 81.8% from 1 A g−1 to 10 A g−1), and long-cycle stability (capacity retention of 63% over 5000 cycles). The excellent electrochemical performance should be due to the abundant active sites provided by rGO combined with proper loading of Bi2O3 nanoparticles.

Evaluation of the reaction mechanism for photocatalytic degradation of organic pollutants with MIL-88A/BiOI structure under visible light irradiation

In this study, we synthesized novel visible light photocatalyst MIL-88A/BiOI using depositing BiOI particles on the surface of a metal–organic framework (MIL-88A). Photocatalytic application of binary composite MIL-88A/BiOI was obtained by discoloration of Methylene Blue (MB) and Acid Blue 92 (AB92) in aqueous solution under visible light source. The photodegradation experiments for treating organic dyes show that the MIL-88A/BiOI heterojunction structure possess a higher rate for decomposition of dyes due to the decreased aggregation of the BiOI nanoparticles, effective charge carrier separation and the synergistic effect between MIL-88A and BiOI samples as a heterojunction. Also, the MIL-88A/BiOI structure shows better photocatalytic degradation performance for anionic dyes (AB92) than for a cationic dye (MB). It was further found that •OH and •O2− radicals were the most important species responsible for the photodegradation test.

Cytotoxicity of 5-ALA-conjugated bismuth oxidenanoparticles on KB cell line

Introduction: In recent years, bismuth-based nanomaterials have been widely used in medical researches as imaging, drug delivery and x-ray radiosensitizing agents. Due to their anti-microbial effects against Helicobacter pylori (HP), bismuth colloidal compounds are used to treat various types of diseases such as chronic gastritis. Despite their advantages, bismuth-based compounds have shown many toxic effects in humans. There are few studies on cytotoxicity effects of bismuth (ΙΙΙ) oxide (Bi2O3) nanoparticles (NPs). Based on the natural high affinity of folate for the folate receptor protein (FR), which is commonly expressed on the surface of many human cancers, folate-drug conjugates bind tightly to the FR and trigger cellular uptake via endocytosis. Therefore, we aimed to investigate the cytotoxicity effects of 5-ALA-conjugated Bi2O3 NPs, 5-ALA-folate-conjugated Bi2O3 NPs and free 5-ALA on oral squamous carcinoma cell line (KB cells) for the first time. 5-ALA is used in photo dynamic detection and photodynamic surgery of cancer. Being a precursor of a photosensitizer, 5-ALA is also used as an add on agent for photodynamic therapy. Materials and Methods: Bi2O3 NPs were synthesized and conjugated with folate and 5- aminolevulinic acid (5-ALA). KB cells were cultured monolayer and incubated with 10, 20, 50, 100 and 200 μg/ml concentrations of free 5-ALA, 5-ALA-folate-conjugated Bi2O3 NPs and 5-ALA-conjugated Bi2O3 NPs for 24 hours. The survival of the cells obtained after 24 h of incubation with the materials using MTT assay. Results: Bi2O3 NPs were synthesized (~20 nm) and conjugated to folate and (5-ALA). Results indicated that the significant cellular death were noted at the concentrations more than of 50 μg/ml for all compounds that cell viability reduced to 37%, 49% and 63% in groups receiving 5-ALA-folate-conjugated NPs, 5-ALA-conjugated Bi2O3 NPs and free 5-ALA, respectively. The cytotoxicity of the materials on KB cells also increased with increasing concentrations of synthesized NPs. Conclusion:5-ALA-folate-conjugated NPs, 5-ALA-conjugated Bi2O3 NPs and free 5-ALA were easily taken up by the cells and showed cytotoxic effects at high concentrations. Folic acid conjugation facilitates selective targeting of the KB cells with the overexpression of the folate receptors and improves internalization of the drugs through receptor-mediated endocytosis

Usefulness of nanoparticles to making shield and protection of sensitive organs in chest CT scan test

Introduction: Recently, the use of nanoparticles has increased for many purpose in medicine. One of these is using the nano particles in shields structure to protect sensitive organs such as breast which placed inside the field of chest CT scan and receives high dose. The aim of this study was the use of nano Bi2O3 to making shield for protection breast in chest CT examination and evaluating their image quality. Method and Materials: The nano Bi2O3 powder was used for create shield at 1mm thickness. The 6-slice CT scan system and PMMA phantom were used for dose measurement. Dose measured once in present of the shield and once in absent of the shield. Also the image quality was measured. Results: Reference average dose was 8.6 mGy in chest CT scan test which changed to 7.4 mGy when Bi2O3 shield was placed on the phantom. Also CT number and noise were raised from 121 HU and 24 to 126 HU and 28. Conclusion: On the base of results, the Bi2O3 nano particles have enough potential for radiation protection and using as a shield for reducing of breast dose in CT scans with acceptable image.

Organic Matrix Stabilized Ultra‐Fine Bismuth Oxide Particles for Electrochemical Energy Storage Application

AbstractThe synthesis of an organic‐inorganic supramolecular hybrid system has been reported, using a wet‐chemical synthesis method, where the Bi2O3 nanoparticles are dispersed within the organic matrix. The XRD analysis showed the formation of crystalline Bi2O3. The XPS and Raman spectra analysis also confirmed the formation of Bi2O3. In this work, the organic molecule supported nanosized Bi2O3 has been used as an electrode material for supercapacitor application in presence of the aqueous solution of alkaline electrolyte (1.0 mol dm−3 of KOH) and exhibited a specific capacitance 407 F.g−1 along with the energy density value of 113 W.h.kg−1 at 1 A.g−1. The supramolecular system exhibited a long‐term stability by retaining 89% of the initial specific capacitance value after 500 cycles at the current density of 5 A.g−1.

Synthesis and enhanced photocatalytic activity of AgI-BiOI/CNFs for tetracycline hydrochloride degradation under visible light irradiation

In this work, a novel AgI-BiOI/CNFs photocatalyst was successfully synthesized through reaction and electrospinning and carbonization processes. According to the results of XRD, XPS, SEM and TEM, BiOI and AgI nanoparticles were loaded onto the carbon nanofibers as expected. Compared with other as-prepared samples, the AgI-BiOI/CNFs(1) displayed highest photocatalytic performances and excellent recyclability, which was estimated through the degradation experiments of tetracycline hydrochloride (TC) under visible light in 3 h. TC was degraded as carbon dioxide and other small molecules. The superoxide radicals (•O2−) was proved to be the main reactive species in trapping experiments. In addition, a possible photocatalytic mechanism of samples was systematically investigated.

Investigating the Cytotoxicity of Folate-Conjugated Bismuth Oxide Nanoparticles on KB and A549 Cell Lines.

Purpose: Lately, bismuth-based nanomaterials have been widely utilized in medical researches such as imaging, drug delivery and radio-sensitization. Despite their advantages, bismuth-based compounds have shown toxic effects in humans. There are few studies on cytotoxicity effects of bismuth oxide (Bi2O3) nanoparticles (NPs) in-vitro. In this study, we aimed to investigate cytotoxicity of bare and also folate and 5-aminolevulinic acid (5-ALA)-conjugated Bi2O3 NPs on nasopharyngeal carcinoma (KB) and lung cancer (A549) cell lines.Methods: Bi2O3 NPs were synthesized and conjugated with folate and 5-ALA. KB and A549 cells were cultured and incubated with 10, 20, 50 and 100 μg/ml concentrations of bare and folate-5-ALA-conjugated NPs. The survival rates were obtained after 2 and 24 hours incubation of the cells with NPs using MTT assay. Also, apoptosis and ROS generation induced by the NPs in the treated cells were obtained using Caspases-3 activity assay and flow cytometry analysis, respectively.Results: Bi2O3 NPs were successfully synthesized with average size of 19.2 ± 6.5 nm, then conjugated with 5-ALA and folate. Either naked or folate-conjugated NPs were easily taken up by the cells in a concentration-dependent manner and showed cytotoxic effects. The significant cell death was noted at the concentrations more than 50 μg/ml for both compounds.Conclusion: Results indicated low cytotoxicity of the prepared NPs at lower incubation periods, which is very important for their further applications. However, 24 hours incubation of the cells with both forms of NPs caused more cell killing and the cytotoxicity increased with increasing concentrations of the NPs.

Size-controlled one-pot polyol synthesis and characterization of D-glucuronic acid-coated ultrasmall BiOI nanoparticles as potential x-ray contrast agent

A polyol method is extremely useful for preparimg metal-containing nanoparticles coated with hydrophilic and biocompatible ligands for biomedical applications. In this study, D-glucuronic acid-coated BiOI nanoparticles were prepared in one-pot using this method. The particle diameter was controlled by varying the solvent volume such that the particle diameter decreased with increasing solvent volume: nanoparticles with average diameters of 1.9 (ultrasmall) and 6.1 nm were prepared at two solvent volumes. The x-ray attenuation properties of the ultrasmall nanoparticles were investigated because of their suitability for in vivo biomedical applications. D-glucuronic acid-coated ultrasmall BiOI nanoparticles were superior to the commercial molecular iodine contrast agent Ultravist® in terms of x-ray attenuation, and showed the highest x-ray attenuation efficiency (η) of ∼21 HU/mM [Bi] that has ever been reported thus far, proving their potential as an extremely powerful x-ray contrast agent.

PVP assisted synthesis of high efficient BiOI/Graphene oxide nanohybrid and its photocatalytic performance in degradation of organic dye pollutants

In this paper, highly visible-light active BiOI/Graphene oxide nanohybrids (BG) were synthesized by a simple solvothermal technique using polyvinylpyrrolidone (PVP). The as-synthesized photocatalysts were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transition electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) and UV–vis diffusive reflectance spectra (UV–vis DRS). The nanohybrid samples synthesized with PVP (BGP) showed extremely high efficiency in photodegradation of Reactive Blue 19 (RB19) under visible light. Specially, BGP-1 photocatalyst (1 wt% of graphene oxide (GO)) exhibited the highest RB19 degradation efficiency (about 100%) in 120 min, which was almost 60% and 65% higher than that achieved by using as-synthesized BG nanohybrids and pure BiOI particles, respectively. The results showed that PVP plays a crucial role as a template and strongly controls the growth of BiOI nanoparticles on the surface of graphene nanosheets. The enhanced photocatalytic performance of BGP-1 nanohybrids could be attributed to significant synergetic effects between graphene and BiOI nanoparticles, higher visible light absorption capacity and migration of photoexcited electrons on high conductive graphene nanosheets. This research suggests that BGP nanohybrid is a promising material for the photodegradation of organic dye pollutants under visible light irradiation and could be used commercially in wastewater treatment units.

Sonochemical synthesis of bismuth(III) oxide decorated reduced graphene oxide nanocomposite for detection of hormone (epinephrine) in human and rat serum

Herein, we report an efficient electrochemical sensor strategy for determination of epinephrine based on Bi2O3 nanoparticle decorated reduced graphene oxide nanocomposite (Bi2O3@RGO). The Bi2O3@RGO was prepared by simple ultrasonic method and then it’s morphological and crystal structure aspects were well characterized by physiological instruments. The electrode-electrolyte interfacial properties were examined to ensure the catalytic ability of composite sensing towards EP. The composite was deposited on the multi-conventional screen-printed electrode and was found to be desirable performance toward EP oxidation. The amperometric EP sensing exhibited good reproducible and sensitive which able to detect as low as concentration of 2.14 nM. Furthermore, good reproducibility, long-term stability and repeatability were obtained from the electrode in experiment. Moreover, the EP sensing method was successfully applied in human and rat blood serum, the recoveries were validated by HPLC method. It indicates the reliability of the method in practical analysis.

Intercalation of Bi2O3/Bi2S3 nanoparticles into highly expanded MoS2 nanosheets for greatly enhanced gas sensing performance at room temperature.

Synthesizing a gas sensor based on heterostructured nanomaterials (NMs) via a controllable morphology by a facile hydrothermal method is an area of frontier research. In the present work, we designed a facile strategy to synthesize a controllable morphology and composition for three component heterojunctions (MoS2-Bi2O3-Bi2S3) NMs using different hydrothermal reaction times. The Bi2S3 easily form as an intermediate phase due to the strong interaction of the Bi2O3 with MoS2 nanosheets (NSs). The as fabricated heterojunctions MB-5 NMs exhibited a sensitive response to NOx gas (Ra/Rg = 10.7 at 50 ppm), with an ultra-fast response time of only 1 s (s) at room temperature (RT) in air. The detection limit was predicted to be as low as 50 ppb. This sensational behaviour of the sensor reveals the outstanding morphological structure and synergistic effect of the MoS2 NSs with Bi2O3 nanoparticles (NPs), which was realized by the flow of electrons across MoS2-Bi2O3-Bi2S3 interfaces through band energy alignment.

Morphology‐Controlled Bi2O3 Nanoparticles as Catalysts for Selective Electrochemical Reduction of CO2 to Formate

AbstractIn this paper, Bi2O3 electrocatalysts for the electroreduction of CO2 to formate were synthesized with different morphologies, including nanoparticles and thin nanorods. Comparatively, Bi2O3 nanoparticles have higher catalytic activity than Bi2O3 thin nanorods. The Faradaic efficiency of formate formation at a moderate potential of −1.2 vs. RHE in aqueous solution could reach 91 %. In addition, a maximum current density for formate production of up to 22 mA cm−2 was achieved, which is almost 3 times higher than that of Bi2O3 thin nanorods. In particular, the catalytic activity of the Bi2O3 nanoparticle catalyst was almost stable over a 23‐hour period of electrolysis, exhibiting its application prospect in the electroreduction of CO2 to formate.

Mechanosynthesis of Nanocrystalline Fully Stabilized bcc γ-phase of Bi2O3 without Any Additive: Manifestation of Ferroelasticity in Microstructure, Optical, and Transport Properties

In the present work, polymorphic phase transformation of Bi2O3 nanoparticles by the mechanical alloying method has been investigated in detail. X-ray diffraction study reveals that the room tempera...

Stabilized β-Bi2O3 nanoparticles from (BiO)4CO3(OH)2 precursor and their photocatalytic properties under blue light

Stabilized tetragonal Bi2O3 nanoparticles (β-Bi2O3) were obtained by annealing treatments of amorphous Bi-based precursors, obtained by chemical precipitations, at temperatures between 350 and 450 °C. The formation of the stabilized β-Bi2O3 phase was possible by using (BiO)4CO3(OH)2 while other precursors such as amorphous bismuth carbonate ((BiO)2CO3) and amorphous basic bismuth nitrate (Bi6O6(OH)2(NO3)4·2H2O) led to the formation of the thermodynamically stable monoclinic α-Bi2O3 and Bi5O7NO3 phases. The Bi-based precursors were prepared by the chemical precipitation method at room temperature in ethylenediamine-solvent varying the HNO3/Bi3+ molar ratio (10, 26 and 56). The physicochemical properties of the three as-prepared amorphous precursors and the formed-after-calcination β-Bi2O3, α-Bi2O3 and Bi5O7NO3 phases were analyzed by X-ray diffraction, scanning electron microscopy, thermogravimetry, X-ray photoelectron spectroscopy (XPS), FTIR analysis, diffuse reflectance spectroscopy and surface area by BET method. The photocatalytic activity of all annealed solids containing the β-Bi2O3 phase was tested in the photodegradation of the indigo carmine (IC) dye under specific blue light. A schematic diagram of the Bi2O3 phases obtained as a function of the annealing conditions and initial amorphous precursor is proposed and explained in terms of the amount of CO32-, NO3- and amine (ENH22+ ⇔ ENH+) ions present in each bismuth precursor.

Boron ignition and combustion with doped δ-Bi2O3: Bond energy/oxygen vacancy relationships

The purpose of this paper is to extract a clearer relationship between atomic properties of the oxidizer, and ignition temperature and combustion kinetics. Pure Bi2O3 and a series of Y3+ and W6+ doped Bi2O3 nanoparticles with the same crystal structure and morphology were synthesized via aerosol spray pyrolysis and used as oxidizers in boron-based thermites. This enabled us to vary bond energy and oxygen vacancy concentration systematically. The ignition temperatures and the reactivities of different B/Bi2O3 thermites were measured by rapid heating (> 105 K/s) temperature-jump/time-of-flight mass spectroscopy and a confined pressure cell, respectively. With pure Bi2O3, the boron could be ignited at a temperature as low as 520 °C. In-situ high heating rate TEM was used to observe the reaction before/after heating. We find very clear relationships that higher oxygen vacancy concentration and smaller metal–oxygen bond energy lead to lower ignition temperature and higher combustion reactivity.

Electrical Properties of Nano Bi2O3 Added (Bi,Pb)Sr-Ca-Cu-O Superconductor

In this study, Bi2O3 nanoparticles were added into (Bi1.6 Pb0.4)Sr2Ca2Cu3O10 (BPSCCO) superconductor. Ultrafine BPSCCO powders were prepared by the co-precipitation method. Bi2O3 with weight percent (wt. %) 0, 0.04, 0.06, and 0.10 was added during the final heating stage. The samples were investigated by x-ray powder diffraction method. Critical current density, Jc was measured between 40 K and 77 K with the 1 μV/cm criterion. DC electrical resistivity was measured using the four point probe method. This result showed that the highest Jc was observed for sample with 0.06 wt. % Bi2O3. A gradual decrease of Jc and transition temperature Tc was observed for samples with greater than 0.06 wt. % Bi2O3.

Entrapment of Bi2O3 nanoparticles in TiO2 nanotubes for visible light-driven photocatalysis

In this study, we prepared nanoparticles of the visible light-responsive photocatalyst, Bi2O3 entrapped in anatase TiO2 nanotubes (Bi2O3-in-TNTs) via a vacuum-assisted precursor-filling process followed by annealing. Owing to the unique tubular electronic structure of TiO2 nanotubes, the interior of the nanotube is in an electron-deficient state, which was confirmed by XPS spectra and H2-TPR. Electrochemical impedance studies showed that the Bi2O3-in-TNTs demonstrated a more efficient separation of photogenerated carriers than when Bi2O3 nanoparticles were deposited on the outer wall of TiO2 nanotubes (Bi2O3-out-TNTs). Due to the confinement effect of TiO2 nanotubes, which inhibits photogenerated carriers’ recombination, the Bi2O3-in-TNTs exhibited a better photocatalytic performance for the photo-degradation of methyl orange under visible light compared to Bi2O3-out-TNTs.

Photocatalytic rendition of Zn2+-doped Bi2O3 nanoparticles

The present work analyzes the photocatalytic activity of Bi2O3 in the pure and Zn2+-doped forms in the degradation of the organic dye methylene blue (MB) under solar light irradiation. For this study, nanoparticles of bismuth oxide (Bi2O3) and different levels of Zn2+-doped Bi2O3 were prepared by a simple chemical precipitation method. The phase form of Bi2O3 is confirmed by X-ray diffraction. The optical properties of the samples were studied by UV–vis-Diffuse Reflectance spectroscopy and photoluminescence. The morphologies of the products were visualized under a field-emission scanning electron microscope (FESEM) and confirmed by transmission electron microscopy (TEM). The degradation profile reveals that Bi2O3 doped with the optimum level of zinc is known to have an excellent catalytic activity owing to the electron trapping–detrapping process of the solar cell.