Bi2O3 Nanoparticles Research Articles

Growth of BiVO4 Nanoparticles on a Bi2O3 Surface: Effect of Heterojunction Formation on Visible Irradiation-Driven Catalytic Performance

Heterostructured materials composed of different semiconductors can be used to decrease rapid charge carrier recombination in photocatalysts, but the development of efficient synthesis methods for these materials remains a challenge. This work describes a novel strategy for tailoring heterostructures that is based on the solubility difference between two semiconductors with at least one metal in common. The growth of BiVO4 on a preformed Bi2O3 particle was used as a model for heterojunction formation. The number of Bi2O3/BiVO4 heterojunctions was tuned using synthesis variables (temperature and V concentration) and the particle size of the preformed Bi2O3. The synthesis of the Bi2O3/BiVO4 heterostructures using Bi2O3 nanoparticles resulted in a larger quantity of heterojunctions due to the higher solubility of the nanoparticles compared to micrometric Bi2O3, which led to a classical heterogeneous precipitation on the preformed surfaces. The proposed growth mechanism was effective for obtaining heterostruc...

Facile synthesis and characterizations of polypyrrole/BiOCl hybrid composites

Polypyrrole(PPy)/BiOCl hybrid composites were synthesized for the first time via one-step chemical oxidation process by addition of Bi2O3 nanoparticle in an aqueous solution of pyrrole monomer/FeCl3 oxidant agent. X-ray diffractions (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric technique confirmed the growth of BiOCl in PPy matrix. From the XRD, the amount of BiOCl in PPy matrix increased with increasing of Bi2O3 addition in pyrrole solution. The FESEM images indicated the presence of two phases related to PPy and BiOCl. Thermal stability of PPy/BiOCl hybrid composites has been improved in the range 300–800 K and degraded above 800 °C, i.e., decomposition point of BiOCl. Fourier transforms infrared spectroscopy point to a mutual interaction between PPy and BiOCl system. The characteristic optical absorption peaks of PPy shifted to higher wavelength in PPy/BiOCl(5%) composites and disappeared at PPy/BiOCl(20%). From electrical measurement, the PPy/BiOCl hybrid composites have higher conductivity than PPy, where the maximum conductivity observed was for PPy/BiOCl(5%). The conducting mechanism of PPy and PPy/BiOCl composites followed three-dimensional Mott variable range hopping in the range of 300–150 K and has involved fluctuation-assisted tunneling phenomenon below 150 K.

Self-assembly behaviour of bismuth oxide nanoparticles assisted by oleylamine

Bi2O3 nanoparticles are prepared by using a facile solution-based thermal decomposition method assisted by oleylamine. These Bi2O3 nanoparticles self assemble into nanobelts. The reaction time and temperature affect self-assembly behaviour of the Bi2O3 nanoparticles. Increasing the reaction time or temperature results in the larger size of nanoparticles, which leads to failure of formation of nanobelts. It is illustrated that oleylamine and the size of nanoparticles play key roles in the self-assembly of nanoparticles. Based on the experimental results, a formation mechanism of the self-assembled nanobelts was proposed and this method may be extended to fabrication of other metal oxide nanobelts.

Preparation of One-dimensional ZnO/Bi2O3 Heterostructures Nanomaterial for Visible Light Photocatalysis

We use a simple route to prepare ZnO@Bi2O3 heterostructures at room temperature by the solid-state reaction method. The paper discussed morphology and photocatalytic properties of different content of ZnO@ Bi2O3 composite nanomaterials. The as-prepared different content of ZnO@ Bi2O3 composite with different content were characterized by SEM, TEM, XRD and Uv-vis spectrometry. We find that the Bi2O3 nanoparticles are well dispersed on the ZnO Nano rods. The result shows that we can the absorption of solar light can be enhanced by coating Bi2O3 and zinc oxide /bismuth oxide sample in sunlight irradiation shows the best photocatalytic activity under sunlight irradiation

Improving Visible Light-Absorptivity and Photoelectric Conversion Efficiency of a TiO2 Nanotube Anode Film by Sensitization with Bi2O3 Nanoparticles

This study presents a novel visible light-active TiO2 nanotube anode film by sensitization with Bi2O3 nanoparticles. The uniform incorporation of Bi2O3 contributes to largely enhancing the solar light absorption and photoelectric conversion efficiency of TiO2 nanotubes. Due to the energy level difference between Bi2O3 and TiO2, the built-in electric field is suggested to be formed in the Bi2O3 sensitized TiO2 hybrid, which effectively separates the photo-generated electron-hole pairs and hence improves the photocatalytic activity. It is also found that the photoelectric conversion efficiency of Bi2O3 sensitized TiO2 nanotubes is not in direct proportion with the content of the sensitizer, Bi2O3, which should be carefully controlled to realize excellent photoelectrical properties. With a narrower energy band gap relative to TiO2, the sensitizer Bi2O3 can efficiently harvest the solar energy to generate electrons and holes, while TiO2 collects and transports the charge carriers. The new-type visible light-sensitive photocatalyst presented in this paper will shed light on sensitizing many other wide-band-gap semiconductors for improving solar photocatalysis, and on understanding the visible light-driven photocatalysis through narrow-band-gap semiconductor coupling.

Preparation of polypyrrole-coated Bi2O3@CMK-3 nanocomposite for electrochemical lithium storage

Polypyrrole-coated Bi2O3@CMK-3 nanocomposite is prepared by nanocasting technique and chemical polymerization method. Bi2O3 nanoparticles are dispersed into CMK-3 matrix, and polypyrrole is coated onto the surface of Bi2O3@CMK-3. Polypyrrole-coated Bi2O3@CMK-3 nanocomposite as an anode material for lithium-ion batteries has an outstanding power capability (321mAhg−1 at a current rate of 6Ag−1) and a significantly improved cycling ability (380mAhg−1 after 1000 cycles at a current rate of 5Ag−1). The greatly enhanced electrochemical performance of polypyrrole-coated Bi2O3@CMK-3 nanocomposite is associated with the synergistic effect of highly conductive CMK-3, polypyrrole layer and Bi2O3 nanoparticles. Such a configuration inhibits the aggregation of Bi2O3 nanoparticles and preserves the structure integrity of electrode material, in addition to highly improving the electrical conductivity and maintaining the stable structure of solid electrolyte interface film.

Green Synthesis and Characterization of Bi2O3 Nanorods as Catalyst for Aromatization of 1,4-Dihydropyridines

Bismuth oxide (Bi2O3) nanorods was prepared via one pot sol-gel method using Bi(NO3)3.5H2O and starch (as template) in water under hydrothermal condition followed by calcination at 320˚C within 3 h. The resultant solid product was characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), thermogravimetry (TGA), and FTIR techniques. Based on the obtained results, the formation of Bi2O3 nanoparticles and nanorods at lower and higher percentage of starch is promising. It was found that Bi2O3 nanorods catalyse the aromatization of 1,4-dihydropyridines (DHPs) with 100% conversion and 100% selectivity.

Enhanced Electrochemical Performances of Bi2O3/rGO Nanocomposite via Chemical Bonding as Anode Materials for Lithium Ion Batteries.

Bismuth oxide/reduced graphene oxide (termed Bi2O3@rGO) nanocomposite has been facilely prepared by a solvothermal method via introducing chemical bonding that has been demonstrated by Raman and X-ray photoelectron spectroscopy spectra. Tremendous single-crystal Bi2O3 nanoparticles with an average size of ∼5 nm are anchored and uniformly dispersed on rGO sheets. Such a nanostructure results in enhanced electrochemical reversibility and cycling stability of Bi2O3@rGO composite materials as anodes for lithium ion batteries in comparison with agglomerated bare Bi2O3 nanoparticles. The Bi2O3@rGO anode material can deliver a high initial capacity of ∼900 mAh/g at 0.1C and shows excellent rate capability of ∼270 mAh/g at 10C rates (1C = 600 mA/g). After 100 electrochemical cycles at 1C, the Bi2O3@rGO anode material retains a capacity of 347.3 mAh/g with corresponding capacity retention of 79%, which is significantly better than that of bare Bi2O3 material. The lithium ion diffusion coefficient during lithiation-delithiation of Bi2O3@rGO nanocomposite has been evaluated to be around ∼10-15-10-16 cm2/S. This work demonstrates the effects of chemical bonding between Bi2O3 nanoparticles and rGO substrate on enhanced electrochemical performances of Bi2O3@rGO nanocomposite, which can be used as a promising anode alterative for superior lithium ion batteries.

Manufacturing and investigation of surface morphology and optical properties of composite thin films reinforced by TiO2, Bi2O3 and SiO2 nanoparticles

Abstract The aim of submitted paper is to present influence of manufacturing parameters on optical properties and surface morphology of composite materials with a polymer matrix reinforced by TiO 2 and SiO 2 and Bi 2 O 3 nanoparticles. The novelty proposed by the authors is the use of TiO 2 and SiO 2 and Bi 2 O 3 nanoparticles simultaneously in polymeric matrix. This allows using the combined effect of nanoparticles to a result composite material. The thin films of composite material were prepared by using spin-coating method with various spinning rates from solutions of different concentration of nanoparticles. In order to prepare the spinning solution polymer, Poly(methyl methacrylate) (PMMA) was used as a matrix. The reinforcing phase was the mixture of the nanoparticles of SiO 2 , TiO 2 and B 2 O 3 . In order to identify the surface morphology of using thin films and arrangement of the reinforcing phase Atomic Force Microscope (AFM) and Scanning Electron Microscope (SEM) were used. In order to study the optical properties of the obtained thin films, the thin films of composites was subjected to an ellipsometry analysis. The measurements of absorbance of the obtained materials, from which the value of the band gap width was specified, were carried out using the UV/VIS spectroscopy. The optical properties of obtain composite thin films depend not only on the individual components used, but also on the morphology and the interfacial characteristics. Controlling the participation of three kinds of nanoparticles of different sizes and optical parameters allows to obtaining the most optimal optical properties of nanocomposites and also controlling the deposition parameters allows to obtaining the most optimal surface morphology of nanocomposites.

Defects and microstructure of a hydrothermally derived (Bi1/2K1/2)TiO3 powder

Fine powders of bismuth potassium titanate (Bi1/2K1/2)TiO3 (BKT) synthesized by hydrothermal reactions have been reported to have good sinterability and high chemical stability against long-time sintering. In this study, detailed chemical and structural characterizations were performed on a hydrothermal BKT powder sample to identify the origin of such properties. The results of X-ray diffraction, infrared transmittance, and diffuse reflectance measurements revealed that the hydrothermal BKT particle contained high concentrations of lattice hydroxyl group and Bi vacancy, whereas the observation by transmission electron microscope showed that its surface was covered with numerous Bi2O3 nanoparticles to achieve the overall stoichiometric cation ratio of BKT. We found that the unique composite nanostructure of the hydrothermal BKT powder led to a large suppression of Bi evaporation during high-temperature sintering, thereby contributing to its superior chemical stability.

Modification of BiOCl Nanosheets with Bi<sub>2</sub>O<sub>3</sub> Nanoparticles by a Facile Two Step Method and the Enhanced Photocatalytic Performance of the Composites

Bi2O3/BiOCl composite photocatalysts were produced by a facile two step method, including ultrasonically modifying BiOCl nanosheets with Bi nanoparticles first and the subsequent in situ thermal oxidation process. The samples were characterized by XRD, SEM, UV-vis and photoluminescence techniques. The photocatalytic activities were evaluated by photodegrading Rhodamine B under Xe light irradiation. The abilities of generating hydroxyl radicals during photocatalysis were tested by fluorescence method. The results show that Bi2O3 NPs were randomly distributed on the surface of BiOCl nanosheets. The photocatalytic efficiency was enhanced after modification and the best photocatalytic activity was obtained when the mole ratio of Bi2O3 to BiOCl was 0.24. The corresponding photochemical reaction rate of Bi2O3/BiOCl was 7 times that of BiOCl nanosheets and 5 times that of Bi2O3 nanoparticles. The improved performance of the composites was considered to associate with the extended light response range and the promoted charge carrier separation.

A two-dimensional bismuth coordination polymer with tartaric acid: Synthesis, characterization and thermal decomposition to Bi2O3 nanoparticles

A two-dimensional bismuth coordination polymer with tartaric acid: Synthesis, characterization and thermal decomposition to Bi2O3 nanoparticles

Self-standing Bi2O3 nanoparticles/carbon nanofiber hybrid films as a binder-free anode for flexible sodium-ion batteries

A flexible binder-free film composed of Bi2O3 nanoparticles embedded in carbon nanofibers as a sodium ion battery anode shows superior electrochemical properties due to its high active area and conducting framework.

Facile electrophoretic deposition of functionalized Bi2O3 nanoparticles

In this work, we prepared uniform Bi2O3 nano-films through facile electrophoretic deposition (EPD) based on stable Bi2O3 nanoparticle suspension. The suspension was obtained by ball-milling Bi2O3 micro-particles in distilled water and employing paper-manufacturing waste sodium lignin sulfonate (MZS) as dispersant. The correlation between the stability of Bi2O3 nanoparticle suspension and EPD parameters including electrostatic repulsion, steric hindrance, and attractive van der Waals force was investigated. The thickness of Bi2O3 films was controlled by adjusting the voltage and time of EPD. This work opens up the opportunity for bismuth oxide nanoparticles to be assembled efficiently for various applications.

Investigation of the toxicity of bismuth oxide nanoparticles in various cell lines

Nanoparticles have been drawn attention in various fields ranging from medicine to industry because of their physicochemical properties and functions, which lead to extensive human exposure to nanoparticles. Bismuth (Bi)-based compounds have been commonly used in the industrial, cosmetic and medical applications. Although the toxicity of Bi-based compounds was studied for years, there is a serious lack of information concerning their toxicity and effects in the nanoscale on human health and environment. Therefore, we aimed to investigate the toxic effects of Bi (III) oxide (Bi2O3) nanoparticles in liver (HepG2 hepatocarcinoma cell), kidney (NRK-52E kidney epithelial cell), intestine (Caco-2 colorectal adenocarcinoma cell), and lung (A549 lung carcinoma cell) cell cultures. Bi2O3 nanoparticles (∼149.1 nm) were easily taken by all cells and showed cyto- and genotoxic effects. It was observed that the main cell death pathways were apoptosis in HepG2 and NRK-52E cells and necrosis in A549 and Caco-2 cells exposed to Bi2O3 nanoparticles. Also, the glutathione (GSH), malondialdehyde (MDA), and 8-hydroxy deoxyguanine (8-OHdG) levels were significantly changed in HepG2, NRK-52E, and Caco-2 cells, except A549 cell. The present study is the first to evaluate the toxicity of Bi2O3 nanoparticles in mammalian cells. Bi2O3 nanoparticles should be thoroughly assessed for their potential hazardous effects to human health and the results should be supported with in vivo studies to fully understand the mechanism of their toxicity.

Controllable fabrication of heterostructured Au/Bi2O3 with plasmon effect for efficient photodegradation of rhodamine 6G

ABSTRACTThree-dimensional (BiO)2CO3 (BSC) nanostructures were synthesised by a hydrothermal reaction, and Bi2O3 nanoparticles were then obtained by calcining BSC precursor at different temperatures. BSC and Bi2O3 samples were then sputtering coated with Au to get the resultant Au/BSC and Au/Bi2O3 for the investigation of the effect of the Au coating on the photocatalytic performance of the samples. The phase structure, morphology and composition of the samples were characterised by X-ray diffraction, scanning electron microscopy and energy-dispersive spectroscopy (EDS). UV–vis diffuse reflectance spectra were used to measure the response of different catalysts to UV–vis light. The photocatalytic activity was investigated for the degradation of rhodamine 6G at room temperature and the light intensity was 1 sun. Bi2O3 exhibited better photocatalytic performance than BSC due to the narrow band gap of Bi2O3, and the coating of Au also endowed the samples with higher photocatalytic capability as compared to the bare one.

Bismuth(III) furfuryl based dithiocarbamates: Synthesis, structures, biological activities and their utility for the preparation of Bi2S3 and Bi2O3 nanoparticles

Tris(N,N-difurfuryldithiocarbamato-S,S′)bismuth(III) (1) and tris(N-furfuryl-N-(2-phenylethyl)dithiocarbamato-S,S′)bismuth(III) (2) have been prepared and characterized by elemental analysis, IR, NMR (1H and 13C) spectra and single crystal X-ray diffraction. Single crystal X-ray structures of 1 and 2 show that the 1 and 2 exist as dimer and monomer, respectively. The coordination geometry of 1 and 2 are pentagonal bipyramidal and pentagonal pyramidal, respectively. The molecular geometry, HOMO–LUMO in the ground state and MEP have been calculated for both complexes using DFT method with LANL2DZ basic set. MEP diagrams support the partial double bond character of C–N(thioureide) bond. Both the complexes have been screened for in vitro antibacterial and antifungal activities and significant activities have been found. In vitro cytotoxicity studies on both the complexes against KB (oral) cell line reveal that IC50 value of 1 (69μg/ml) is less than that of 2 (317μg/ml). Complexes 1 and 2 were used as single source precursors for the preparation of Bi2S3 and Bi2O3 nanoparticles, respectively. The Bi2S3 and Bi2O3 have been characterized by powder X-ray diffraction, EDAX, HR-TEM, IR, UV–Vis and fluorescence spectroscopy. Powder X-ray diffraction analysis reveal orthorhombic phase and monoclinic phase for so obtained Bi2S3 and Bi2O3 nanoparticles, respectively. Photocatalytic activities of Bi2S3 and Bi2O3 were evaluated by decolourization of Rhodamine-B in aqueous solution under ultraviolet irradiation.

First proof of bismuth oxide nanoparticles as efficient radiosensitisers on highly radioresistant cancer cells

This study provides the first proof of the novel application of bismuth oxide as a radiosensitiser. It was shown that on the highly radioresistant 9L gliosarcoma cell line, bismuth oxide nanoparticles sensitise to both kilovoltage (kVp) or megavoltage (MV) X-rays radiation. 9L cells were exposed to a concentration of 50μg.mL−1 of nanoparticle before irradiation at 125kVp and 10MV. Sensitisation enhancement ratios of 1.48 and 1.25 for 125kVp and 10MV were obtained in vitro, respectively. The radiation enhancement of the nanoparticles is postulated to be a combination of the high Z nature of the bismuth (Z=83), and the surface chemistry. Monte Carlo simulations were performed to elucidate the physical interactions between the incident radiation and the nanoparticle. The results of this work show that Bi2O3 nanoparticles increase the radiosensitivity of 9L gliosarcoma tumour cells for both kVp and MV energies. Monte Carlo simulations demonstrate the advantage of a platelet morphology.

Bi2O3 nanoparticles encapsulated by three-dimensional porous nitrogen-doped graphene for high-rate lithium ion batteries

A composite consisting of Bi2O3 nanoparticles encapsulated by three-dimensional (3D) porous nitrogen-doped graphene is reported. Due to the 3D porous structure, the composite has large specific surface area of 112 m2 g−1, which can increase the contact area between active material and electrolyte. In addition, the 3D porous conductive framework can not only facilitate the fast electron transport and Li+ diffusion but also enhance the electrical conductivity of the composite. As expected, the composite shows an outstanding rate capability of 273 mAh g−1 at 10000 mA g−1 and a capacity of 417 mAh g−1 over 100 cycles at a current density of 200 mA g−1. Therefore, the composite is a promising candidate as an anode material for high-rate lithium ion batteries.

Synthesis, characterization, cytotoxicity and antimicrobial studies on Bi(III) dithiocarbamate complexes containing furfuryl group and their use for the preparation of Bi2O3 nanoparticles

Bismuth(III) dithiocarbamate complexes, tris(N-furfuryl-N-propyldithiocarbamato-S,S′)bismuth(III) (1), tris(N-furfuryl-N-butyldithiocarbamato-S,S′)bismuth(III) (2) and tris(N-furfuryl-N-benzyldithiocarbamato-S,S′)bismuth(III) (3), have been prepared and characterized by microanalysis, and spectroscopy (IR and NMR). Structure of 3 has been obtained by single crystal X-ray diffraction. This complex contains distorted pentagonal pyramidal Bi(III) centres which attain an overall distorted pentagonal bipyramidal coordination via long range intermolecular Bi⋯S interactions. DFT quantum mechanical studies of 3 were carried out, supporting the partial double bond character of C–N (thioureide) and C–S bonds in dithiocarbamate ligands. All the compounds have been screened against a panel of microbes viz. Vibrio cholerae, Bacillus subtilis, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, Aspergillus niger and Candida albicans. Complexes 1 and 3 were found to have better activity against K. pneumoniae, V. cholerae, A. niger and C. albicans than the complex 2. Complexes 1–3 have been evaluated for their in vitro cytotoxic activity against KB cells. Complexes 1 and 3 showed higher activity than 2. Bi2O3 obtained from thermal decomposition of 3 has been characterized by PXRD, HRTEM, EDAX, UV–Vis and Fluorescence spectroscopy. PXRD study showed that the sample is composed of monoclinic phase of α-Bi2O3. Photocatalytic activity of as-prepared α-Bi2O3 was determined by decolourization of rhodamine-B in aqueous solution under ultra violet irradiation.