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TiO2 nanotube arrays (TNTA) were prepared by anodization, and then bismuth oxide (Bi2O3) was deposited on TNTA by vacuum impregnation‐chemical precipitation method to prepare Bi2O3@TNTA composite electrodes, which were used to detect 4‐nitrophenol (4‐NP) as an electrochemical (EC) sensor. The effects of the Bi2O3 loading amount and the pH value of the detection solution on the detection performance were exhaustively studied. Under best conditions, the linear range is 5 μΜ–30 mM, the sensitivity is 0.6696 μA ⋅ μM−1 ⋅ cm−2, and the limit of detection is 0.64 μΜ. The composite electrodes are characterized by outstanding reproducibility, superior stability and strong selectivity. [ABSTRACT FROM AUTHOR]

Lithium‐sulfur batteries (LSBs) are greatly promising next‐generation energy storage systems due to their high theoretical specific capacities and energy density. However, the dissolution of lithium polysulfides (LIPs) causees low capacity and short lifespan, impeding the practical application of LSBs. To address this challenge, the composites of oxygen‐doped porous carbon nanotubes (CNTs) wrapped in Bi2O3 were synthesized by the calcinating method (CNTs@Bi2O3). The CNTs@Bi2O3 composites as absorbent immobilize LIPs via the physical limitations of porous CNTs and the chemical adsorption of Bi2O3 and carbon‐oxygen polar bond. After loading sulfur, the CNTs@Bi2O3/S composites with the encapsulated structure can provide a large space to withstand the significant volume expansion during the electrochemical reaction process, ensuring the stability of the electrode structure. Thus, the batteries with CNTs@Bi2O3/S exhibit a high capacity (1232 mA h g−1 at 0.1 C) and good cycle stability (639.1 mA h g−1 after 150 cycles at 0.5 C). This work presents an innovative design suitable for the encapsulated structure of Bi2O3, serving as a valuable reference for the development of Bi2O3 in LSBs. [ABSTRACT FROM AUTHOR]

The electrical transport performance of bulk SrTiO 3 thermoelectric materials can be optimized by incorporating uniformly dispersed conductive inclusions. Herein, the impact of Bi 2 O 3 addition on the thermoelectric properties of La-doped strontium titanate composite nano Ti powder (Sr 0. 875 La 0. 1 TiO 3-δ /20 wt% Ti) has been examined. During the sintering process, Bi 2 O 3 gradually transforms into a liquid phase to facilitate Redox reactions with nano Ti and mass transfer, followed by reduction and transformation into Bi–Bi 2 O 3 particles that precipitate at grain boundaries. The presence of nanoscale Bi-rich phases reduces carrier transport barriers at grain boundaries and enhances phonon relaxation time associated with grain boundary scattering. Ultimately, the sample containing 10 wt% bismuth oxide exhibits the lowest lattice thermal conductivity and the highest weighted mobility. This led to a maximum power factor of 498 μW/mK2 at 873 K and a maximum ZT value of 0.188 at 1073 K. This study presents a novel approach to decouple electroacoustic transport through the utilization of Redox reactions between multiple phases, offering valuable insights for the development of high-performance thermoelectric oxide composites. [ABSTRACT FROM AUTHOR]

The bismuth oxide/polyacrylonitrile (Bi2O3/PAN) composite nanofiber film was prepared by electrospinning technology to explore the preparation process of the film and its X-ray protection performance. During the preparation process, we took polyethylene glycol (PEG) as dispersant and PAN as polymer, then dispersed Bi2O3 into the polymer solution. The effect of Bi2O3 content on the morphology, mechanical properties and X-ray protection of the film were investigated. The results indicate that the nanofiber film with light weight (0.21 g/cm³ density), uniform particle dispersion and good fiber morphology can be obtained by electrostatic spinning and drying at 60 °C for 2 h, at the mass percentage of Bi2O3 and PAN of 160%. The nanofiber film has good X-ray protection effect, with X-ray attenuation efficiency above 50% during the tube voltage rising from 20 kV to 120 kV, and the mass attenuation coefficient reaching 62.16 cm²/g under the voltage of 20 kV. It has great significance for the development of X-ray protection materials with lead-free, lightweight and high shielding efficiency. [ABSTRACT FROM AUTHOR]

This research developed glass material from Perlite. The glasses chemical formula is 20Na2O:40B2O3:(40-X)Perlite:XBi2O3 where X are 0,5,10,15,20, and 25 W% by the melt quenching technique. Physical, optical, its radiation shielding abilities were studied by measuring density, refractive index, transmittance, mass attenuation coefficients, linear attenuation coefficients, and the half value layer (HVL). Densities and refractive indexes of glasses decreased as bismuth oxide (Bi2O3) concentration increased. Transmittance percentage from UV–Visible spectrophotometer showed the highest transmission at 15% concentration of Bi2O3. For radiation shielding properties, the linear attenuation coefficient and the mass attenuation coefficient calculated from WinXCom program showed increasing via added content Bi2O3. The HVL of 5 W% Bi2O3 doped glass is lower than that of concrete. The results of this research show that perlite glass has an ability for radiation shielding material. [ABSTRACT FROM AUTHOR]

Bismuth oxide (Bi2O3) is a promising additive to decrease the sintering temperature of yttria‐stabilized zirconia (YSZ)‐based electrolyte for solid oxide fuel cell application. However, Bi2O3 tends to grow into large column bars (>50 µm) in a chemical coprecipitation method, which dramatically limits the mixing uniformity of Bi2O3 and YSZ, even much worse than that of mechanical mixing. In this study, the reaction temperature was increased from room temperature to 90°C to increase the number of nucleation during the violate reaction between Bi3+ solution and YSZ suspension in NaOH. On this basis, the violence of the reaction was further moderated by adding half of NaOH first, then YSZ powders and the other half of an NaOH solution. The size of Bi2O3 was further decreased to sub‐micrometer and Bi2O3 was homogeneously mixed with YSZ particles, even when its addition amount was as large as 20 mol%. These composite powders effectively promoted the sintering behavior of YSZ. The sintering temperature of YSZ was decreased to 900 and 1000°C with 10 and 5 mol% Bi2O3 doping, respectively. Increasing the doping ratio induced severe volatilization of Bi2O3 and pore formation. Raising the sintering temperature (no more than 1200°C) enhanced the doping effect of Bi2O3 into the YSZ lattice but induced instability in the YSZ crystal structure. [ABSTRACT FROM AUTHOR]

The purpose of this research is to evaluate the intent of empty fruit bunches of palm oil (EFBpalm oil) to catalytic gasification of wood produced charcoal (Woodcharcoal) in order to notify the large-scale application of Woodcharcoal as a possible gasification feedstock. In this study, co-catalyst of bismuth oxide (Bi2O3) was also used to obtain syngas. The raw samples were characterized by proximate and ultimate analyses, X-ray diffraction (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) analyses. The produced syngas was analyzed by online portable gas analyzer and gas chromatography-thermal conductivity detector (GC-TCD). The syngas composition of H2 increased from 3.91 to 4.70% (increased 20.20%), CO increased from 5.73 to 6.30% (increased 10.53%), whereas CO2 decreased from 20.60 to 12.67% (decreased 38.50%) and CH4 concentration increased insignificantly from 0.35 to 0.37% (increased 5.7%) which was happened due to the use of WoodCharcoal and Bi2O3 with EFBpalm oil during gasification. According to the findings, carbon is abundant in WoodCharcoal, which may considerably boost the gasification reactivity with Bi2O3. The yield of syngas (H2 and CO) increased when WoodCharcoal and Bi2O3 were used instead of single EFBppo gasification, indicating that catalyst (WoodCharcoal) and co-catalyst (Bi2O3) have a high potential for thermal decomposition and dehydrogenation of volatile matter. Therefore, catalytic gasification of empty palm fruit bunches will be the prospective energy sources for the production of syngas with the utilization of WoodCharcoal and Bi2O3. [ABSTRACT FROM AUTHOR]

This paper investigates the pivotal role of bismuth oxide (Bi₂O₃) in the enhancement of nuclear safety, structural, and thermal properties of glasses, specifically in the BNLS system. BNLS system has the formula [B 2 O 3 –Li 2 O–SiO 2 ]-Nb 2 O 5(20-x) –(Bi 2 O 3) x (where x = 0.0,5.0,10.0,15.0 and 20.0 mol%). Through a comparative study, the potential advantages, and limitations of integrating Bi₂O₃ in place of traditional elements are highlighted, emphasizing its importance in the field of advanced glass materials. FTIR analysis showed the presence of Bi–O vibrations of the tetrahedral [BO 4 ] groups and the Bi–O–Bi linkages. DSC testified the glass formation with increasing thermal stability of the formed glass with the inclusion of Bi 2 O 3 into the glass system. Through the quantification of the Gamma Linear Attenuation Coefficient (G LAC) and Gamma Mass Attenuation Coefficient (G MAC), the work identifies the attenuation behavior against varying photon energies. Notably, a concentration-dependent rise in attenuation characteristics is observed, with BNLS20 exhibiting the most potent radiation shielding. Glass Half-Value Layer (G HVL) parameters and Mass Gamma Photon Penetration (G MFP) were measured, reinforcing that glasses with higher Bi 2 O 3 concentrations and lower G HVL are better attenuators. The transmission factor (ln(I/Io)) was also studied, confirming that BNLS20 possesses the most effective radiation shielding capabilities. This research establishes that adding Bi₂O₃ to the [B 2 O 3 –Li 2 O–SiO 2 ]-Nb 2 O 5 glass system markedly improves its thermal stability and radiation shielding capabilities. BNLS20, in particular, emerges as a standout for radiation protection, surpassing both other BNLS variants and conventional shielding materials, thereby positioning it as an exceptional choice for advanced nuclear safety applications. • The substitution of Bi₂O₃ for Nb₂O₅ in a [B₂O₃-Li₂O–SiO₂]-Nb₂O₅ glass system was studied. • The structural, thermal, and nuclear safety for the glass system were investigated. • Gamma shielding characteristics of the materials were investigated. • Remarkable results in thermal and nuclear safety properties were obtained. [ABSTRACT FROM AUTHOR]

For extensive radiation exposure, inventing a novel radiation shielding material is a burning issue at present for the purpose of life saving. Considering this thought, in this study, by adding sundry amounts of Bi2O3 into pure high-density polyethylene (HDPE), six HDPE systems were prepared to evaluate the radiation shielding efficiency. These HDPE systems were HDPEBi-0 (pure HDPE), HDPEBi-10 (10 wt% Bi2O3), HDPEBi-20 (20 wt% Bi2O3−), HDPEBi-30 (30 wt% Bi2O3), HDPEBi-40 (40 wt% Bi2O3), and HDPEBi-50 (50 wt% Bi2O3). The values of the linear attenuation coefficients of the experimental results (calculated in the lab using HPGe) were compared with the theoretical results (obtained using Phy-X software) at 0.060, 0.662, 1.173, and 1.333 MeV energies. To ensure the accurateness of the experimental results, this comparison was made. It was crystal clear that for energy values from 0.06 MeV to 1.333 MeV, all the experimental values were in line with Phy-X software data, which demonstrated the research setup's reliability. Here, the linear attenuation coefficient (LAC), and mean free path (MFP) shielding parameters were assessed. At the energy of 1.333 MeV, sample HDPEBi-0 showed an HVL value 1.7 times greater than that of HDPEBi-50, yet it was 23 times greater at 0.0595 MeV. That means that for proper radiation protection, very-low-energy HDPE systems containing 10–50% Bi2O3 could be used; however, the thickness of the HDPE system must be increased according to the energy of incident radiation. [ABSTRACT FROM AUTHOR]

This work theoretically compared the X-ray attenuation capabilities in natural rubber (NR) composites containing bismuth oxide (Bi2O3) by determining the effects of multi-layered structures on the shielding properties of the composites using two different software packages (XCOM and PHITS). The shielding properties of the single-layered and multi-layered Bi2O3/NR composites investigated consisted of the transmission factor (I/I0), effective linear attenuation coefficient (µeff), effective mass attenuation coefficient (µm,eff), and effective half-value layer (HVLeff). The results, with good agreement between those obtained from XCOM and PHITS (with less than 5% differences), indicated that the three-layered NR composites (sample#4), with the layer arrangement of pristine NR (layer#1)-Bi2O3/NR (layer#2)-pristine NR (layer#3), had relatively higher X-ray shielding properties than either a single-layer or the other multi-layered structures for all X-ray energies investigated (50, 100, 150, and 200 keV) due to its relatively larger effective percentage by weight of Bi2O3 in the composites. Furthermore, by varying the Bi2O3 contents in the middle layer (layer#2) of sample#4 from 10 to 90 wt.%, the results revealed that the overall X-ray shielding properties of the NR composites were further enhanced with additional filler, as evidenced by the highest values of µeff and µm,eff and the lowest values of I/I0 and HVLeff observed in the 90 wt.% Bi2O3/NR composites. In addition, the recommended Bi2O3 contents for the actual production of three-layered Bi2O3/NR composites (the same layer structure as sample#4) were determined by finding the least Bi2O3 content that enabled the sample to attenuate incident X-rays with equal efficiency to that of a 0.5-mm lead sheet (with an effective lead equivalence of 0.5 mmPb). The results suggested that the recommended Bi2O3 contents in layer#2 were 82, 72, and 64 wt.% for the combined 6 mm, 9 mm, and 12 mm samples, respectively. [ABSTRACT FROM AUTHOR]

Bismuth oxide synthesis using hydrothermal method has been conducted. This study aims to examine the effect of the hydrothermal reaction time on product characteristics and photocatalytic activity in degrading methyl orange dye. Bismuth oxide synthesis was initiated by dissolving bismuth nitrate pentahydrate (Bi(NO3)3.5H2O) and Na2SO4 in distilled water and added NaOH gradually. The solution formed was transferred into a Teflon-lined autoclave and heated at 120 °C with time variations of 8-16 h. The formation of bismuth oxide was indicated by the vibrations of the Bi-O-Bi and Bi-O groups and the crystal structure consisting of α-Bi2O3, β-Bi2O3, and γ-Bi2O3. In addition, the highest photocatalytic activity can be examined through several factors, such as: content of Bi-O-Bi and Bi-OH groups, crystal structure, band gap values, morphology, and surface area, acquired as a result of the effect of hydrothermal reaction time. [ABSTRACT FROM AUTHOR]

A novel electrochemical activation method was used to convert Bi(OH) 3 into α-Bi 2 O 3 with abundant oxygen vacancies. This material has a high specific capacitance and more persistent cycling stability than δ-Bi 2 O 3.When assembled into a hybrid supercapacitor, it shows an energy density of up to 114.9 Wh kg−1. [Display omitted] Bi 2 O 3 is an outstanding electrode material due to its high theoretical specific capacity. Hence, the synthesis of δ-Bi 2 O 3 materials with high oxygen-vacancy contents could improve their electrochemical performances but causes easy conversion to α-Bi 2 O 3 with low oxygen-vacancy contents, leading to poor cycling stability and limited practical applications. To overcome these problems, an effective strategy for constructing high oxygen vacancies α-Bi 2 O 3 on activated carbon fiber paper (ACFP) is developed in this study. To this end, ACFP/Bi(OH) 3 is first synthesized by the solvothermal method and then converted to ACFP/α-Bi 2 O 3 by in situ electrochemical activation. The proposed innovative electrochemical method quickly and easily introduces oxygen vacancies while preserving the three-dimensional structure, thereby promoting the charge transfer and ions diffusion in ACFP/α-Bi 2 O 3. Consequently, the specific capacity of ACFP/α-Bi 2 O 3 reaches 906C g−1 at 1 A g−1, and the capacity retention remains above 70% after 3000 cycles, a value higher than that of δ-Bi 2 O 3 (45%). Furthermore, the hybrid supercapacitor device assembled by ACFP/α-Bi 2 O 3 delivers a maximum energy density of 114.9 Wh kg−1 at 900 W kg−1 and outstanding cycle stability with 73.56 % retention after 5500 cycles. In sum, the proposed ACFP/α-Bi 2 O 3 with high performance and good stability looks promising for use as bismuth-based anode materials in supercapacitors and aqueous batteries. [ABSTRACT FROM AUTHOR]

[Display omitted] In Ti 3 C 2 quantum dots (Ti 3 C 2 QDs)/Bi 2 O 3 photocatalysts system, Ti 3 C 2 QDs can act as a co-catalyst to greatly boost the photocatalytic performance of Bi 2 O 3. Ti 3 C 2 QDs with excellent light adsorption ability can improve the light response of the system, and the fascinating electronic property can function as a channel for electron transfer. Moreover, Ti 3 C 2 QDs possess larger specific area and more active edge atoms thanks to the size effect. The best Ti 3 C 2 QDs/Bi 2 O 3 composite with the loading amounts of 75 mL of Ti 3 C 2 QDs solution showed much higher photocatalytic performance (nearly 5.85 times) for tetracycline (TC) degradation than that of pristine Bi 2 O 3 under visible light irradiation. These different photocatalytic performances shed light on the key role of Ti 3 C 2 QDs in stimulating the photocatalytic activity of Bi 2 O 3. Moreover, Ti 3 C 2 QDs/Bi 2 O 3 composites exhibited excellent stability in recycling experiments and actual water sample treatment. [ABSTRACT FROM AUTHOR]

Nano-structured Bi1.5(Lu, Er)0.5O3 was synthesized efficiently and utilized as a novel environmentally benign and recyclable heterogeneous catalyst for the synthesis of tetrasubstituted imidazole derivatives in water under ultrasonic irradiation. This synthesis method offers the several advantages such as green and eco-friendly protocol, operational simplicity, mild reaction conditions, short reaction time, higher yields, and easy work-up procedures. For this purpose, nano-structured bismuth oxide and Lu3+, Er3+ co-doped Bi2O3 with different Lu3+, Er3+ loadings (0.1, 0.5%mol) were synthesized by a simple hydrothermal method. The obtained catalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope, Fourier-transform infrared spectroscopy, and UV–Vis absorption spectroscopy. X-ray analyses of obtained bismuth oxide were indexed as monoclinic phase and nano co-doped bismuth oxides (Bi2 –x (Lu, Er)xO3, x = 0.1, 0.5%mol) have tetragonal phase. [ABSTRACT FROM AUTHOR]

Alpha phase bismuth oxide (α-Bi2O3) microparticles were prepared through the annealing at 600 °C of basic bismuth nitrate [Bi6O6(OH)2(NO3)4·2H2O] precursors with different morphologies and crystallinity that were obtained by a chemical precipitation method. The precursors were synthesized using ethylenediamine (EN) solvent and varying the HNO3/Bi3+ and HNO3/EN molar ratios, with and without thermal reflux. The influence of the HNO3/EN molar ratio and the thermal reflux on the physicochemical properties of the Bi6O6(OH)2(NO3)4·2H2O precursors and the obtained α-Bi2O3 phase were analyzed by X-ray diffraction, thermogravimetric and differential scanning calorimetric analysis, FTIR analysis, scanning electron microscopy and diffuse reflectance spectroscopy. A correlation between the chemical composition of the Bi6O6(OH)2(NO3)4·2H2O precursors and the physicochemical properties of α-Bi2O3 phase was proposed. Finally, the photocatalytic activity of the α-Bi2O3 microparticles was tested in the photodegradation of indigo carmine dye under UV–A light. [ABSTRACT FROM AUTHOR]

In this work, we have examined the effect of annealing temperature on Cu-doped Bi2O3 thin films at 1%, 3% and 5% doping rate successfully prepared by spray pyrolysis technique onto glass substrates. The obtained films were subsequently annealed at different temperature for 4 h. GIXRD analysis reveals the polycrystalline nature of deposited films and shows the formation of mixed β - and γ -Bi2O3 phases. With the increase of doping rate, α -phase of Bi2O3 was identified at medium temperature. The average grain size of thin films at different doping rate of Cu decreases with the increase of annealing temperature. The optical characterization shows that the optical transmittance of the films decreases with the increase of annealing temperature in the range (70–50%) and (40–10%) for 1% and 5% doping rate of Cu, respectively. The evaluation of the optical bandgap energy reveals that the indirect transition is controlling the optical response of the films. The optimum annealing temperature to reduce Bi2O3 energy bandgap to be 3.09 eV, is 450∘C and 550∘C for 3% and 5% doping rate of Cu. [ABSTRACT FROM AUTHOR]

It is well‐known that photogenerated charge separation is the key and bottleneck step to determine the solar energy efficiency in photocatalysis. Although strategies for facilitating spatial charge separation of semiconductor‐based photocatalysts like heterojunctions, especially for heterophase junctions have been recognized as useful and adequate approaches, the original morphology‐tailored structures are always challenging to be maintained during the thermal‐induced phase transformation process. Herein, using a facile self‐templated method, we successfully fabricate heterophase junction into the well‐defined hierarchical porous structure of visible‐light‐responsive semiconductor, bismuth oxide (Bi2O3), without destroying the its unique hierarchical porous morphology. Such organic integration of heterophase junction and hierarchical porous structure are demonstrated to enable highly efficient separation of photogenerated electrons and holes, resulting in a remarkable enhancement in photocatalytic activities. Our work showcases a general concept for developing artificial photocatalyst systems via integrating efficient charge separation path into the unique morphology‐tailoring of semiconductors for highly efficient solar energy conversion. [ABSTRACT FROM AUTHOR]

The effect of bismuth oxide (Bi 2 O 3) nanoparticles synthesized via laser ablation route on polymeric materials composed of PEO/PVP blend was studied. The future utilization of these materials is highly dependent on their structural, morphology, thermal, and electrical qualities being improved. The observed disappearance of the patterns at 2θ = 19.6° and 23.7° in XRD can be attributed to the elevated temperature resulting from the laser beam, which in turn causes the breakup of PEO-PVP chains which confirm the incorporation of Bi 2 O 3 nanoparticles in PEO-PVP complex. The crystal size of Bi 2 O 3 nanoparticles has been determined to be 20 nm. FT-IR spectra confirms the interactions between Bi 2 O 3 nanoparticles and PEO-PVP matrix. Ultraviolet/Visible (UV–Vis) analysis obtains reducing in band-gap by increasing Bi 2 O 3 nanoparticles concentration upon the blend. The change in surface morphology is confirmed by FESEM images by appearing white spots on the surface of PEO-PVP and increasing cluster size of PEO of composite by addition of Bi 2 O 3 NPs. Also, the thermal stability is improved by shifting Thermogravimetric (TG) curves doped with Bi 2 O 3 NPs toward higher temperature by increasing ablation time. Electrical conductivity results show reducing in both dielectric constant (ε ′) and dielectric loss (ε '') as the frequency rises. The modifications in both optical and electrical conductivity characterization lead to optimizing compositions in electrical applications. • PEO/PVP Co-polymeric blend merged with Bi 2 O 3 NPs was successfully prepared by laser ablation. • XRD showed a decrease in crystallinity with increasing Bi 2 O 3 NPs content. • Results confirmed the interaction between PEO/PVP and Bi 2 O 3 NPs. • Improvement lead to optimizing compositions for optical coatings, optoelectronic devices. [ABSTRACT FROM AUTHOR]

Abstract A novel photoelectrochemical (PEC) immunosensor was successfully constructed for N6-methyladenine (m6A) detection based on the photoactive materials of black titanium dioxide (B-TiO 2) and bismuth trioxide (Bi 2 O 3) and the signal amplification unit of [Ru(bpy) 3 ]2+-doped metal organic framework (MOF). The Bi 2 O 3 /B-TiO 2 /ITO electrode was first fabricated, then decorated with gold nanoparticles (AuNPs) which provided sites for anchoring m6A antibodies. After the capture of m6A via immunoreaction with the antibody, the Zr-based metal organic framework (UiO-66)-[Ru(bpy) 3 ]2+ compound was further attached specifically to the phosphate group of m6A. With visible light irradiation, a large and stable photocurrent response was produced in the presence of ascorbic acid (AA). Under optimized experimental conditions, the linear range of the PEC biosensor was 0.05–30 nM, with a low detection limit of 0.0167 nM (S/N = 3). This method showed high specificity, selectivity, stabilization and repeatability. Moreover, it was successfully used for the detection of m6A in rice seedling leaves that had been subjected to heavy metal treatment during their development. Graphical abstract fx1 Highlights • A novel PEC strategy was developed for sensitive detection of m6ATP. • It was based on the Ru@UiO-66, Bi 2 O 3 and Black TiO 2. • This is the first time that biosensor Bi 2 O 3 /Black-TiO 2 heterojunction was used in biosensing. • The low detection limits of 0.0167 nM for m6ATP was achieved. [ABSTRACT FROM AUTHOR]

In this work, we report a bismuth oxide film electrode with oxygen defects and honeycomb multilevel structure prepared by one-step hydrothermal method. The control of raw materials enables to control the thickness and morphology of BiO electrodes. The photoelectrocatalytic of prepared electrodes were tested in various conditions. Under visible light irradiation (λ ≥ 420 nm) and 3 V bias, the sample BiO-2 has the highest photoelectrocatalytic activity, which is 4.95 times higher than the photocatalytic activity and 9.86 times higher than the electrocatalytic activity. The oxygen defects of bismuth oxide were confirmed by EPR and DFT calculation. The morphology and structure of prepared samples were tested by XRD, scanning electronic microscope (SEM), high-resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS). The enhanced photoelectrocatalytic activity is attributed to the proper bias voltage, oxygen defects, and honeycomb multilevel structure. The results of tapping experiments showed that the main active species during the photoelectrocatalytic progress is superoxide radical and the mechanism of the photoelectrocatalysis was proposed. [ABSTRACT FROM AUTHOR]

In this paper, lignin carbon/bismuth oxide (LC/Bi 2 O 3) composites were successfully synthesized. They were characterized by X-ray powder diffraction, field emission scanning electron microscopy, Fourier transform infrared spectroscopy, etc. and their electrochemical properties were also tested. The results show that the morphology of LC/Bi 2 O 3 composites is lignin pellets which are surrounded with Bi 2 O 3 nanosheets. The lignin carbon in the composites mainly exists in an amorphous structure, and the presence of lignin carbon increases the specific surface area and pores of metal oxides. The electrochemical performance test shows that at the carbonization temperature of 450 °C, LC/Bi 2 O 3 will obtain the highest specific capacitance, and after 1000 cycles of testing, the capacitance retention rate reaches 98.99%, which demonstrates that the composite material has good cycle stability. It is found that the specific capacitance of LC/Bi 2 O 3 –450 °C is 1.3 times and 1.2 times that of Bi 2 O 3 –450 °C and LC-450 °C, respectively when compared with the control group. This shows that lignin carbon and metal oxides promote and cooperate in electrochemical testing. Furthermore, the composites exhibited properties of pseudocapacitive capacitors, indicating that redox reactions occurred in electrochemical performance tests. • Using alkali lignin as carbon source, a new LC/Bi 2 O 3 composite was synthesized. • Morphology of LC/Bi 2 O 3 composites is lignin pellets are wrapped with Bi 2 O 3 nanosheets. • Specific capacitance of LC/Bi2O3–450 °C is 1.3 times and 1.2 times that of Bi2O3–450 °C and LC-450 °C, respectively. • Lignin carbon and the metal oxide promote each other and act synergistically. [ABSTRACT FROM AUTHOR]

In recent years, the usage of nitroaniline has played a vital role in pharmaceutical formulations as it is a crucial ingredient in the synthesis of pesticides and dyes. However, the level of nitroaniline existing in industrial waste keeps rising the environmental contamination. Thus, monitoring of active nitro-residuals becomes more significant in reducing the toxicity of the ecosystem. Therefore, we have taken an attempt to evaluate the hazardous pollutant 2-nitroaniline (2-NA) using the electrocatalyst viz., tin-doped bismuth oxide inserted on a biopolymer silk fibroin composite modified glassy carbon electrode (Sn–Bi 2 O 3 /SF@GCE). The Sn–Bi 2 O 3 /SF nanocomposite was synthesized through hydrothermal and co-precipitation methods. The physicochemical properties of the prepared Sn–Bi 2 O 3 /SF hybrid composite were examined by conventional microscopy and spectroscopic techniques like FE-SEM, HR-TEM, XRD, FTIR, Raman, and XPS. Furthermore, the bio-mineralized Sn–Bi 2 O 3 /SF@GCE displayed a wide linear range (0.009 μM–785.7 μM) and a lower detection limit (3.5 nM) with good sensitivity for 2-NA detection under the optimum conditions. The result shows that the Sn–Bi 2 O 3 /SF-modified GCE has good reproducibility, repeatability, and excellent selectivity for 2-NA detection in the presence of other co-interfering compounds. Moreover, the practical applicability of Sn–Bi 2 O 3 /SF@GCE sensors was investigated for the effective detection of 2-NA in real river water samples, revealing good recovery results. Electrochemical determination of 2-nitroaniline in river water samples. [Display omitted] • Sn–Bi 2 O 3 /SF composite synthesized via hydrothermal and co-precipitation methods. • The bio-mineralized nanoparticles shows excellent electro catalytic performance in electrochemical sensors techniques. • The hybrid composite fabricated electrode revealed highly selective and sensitive detection of 2-nitroaniline. • The practical applicability of Sn–Bi 2 O 3 /SF sensors utilized river water sample analysis. [ABSTRACT FROM AUTHOR]

Potassium-ion batteries (PIBs) are expected to replace lithium-ion batteries (LIBs) as the next generation of electrochemical energy storage products. However, due to the large radius of potassium ion, the anode material undergoes drastic volume expansion during the battery cycle, resulting in performance degradation. Bi 2 O 3 is a kind of material with high theoretical specific capacity, but there is seldom research in potassium-ion batteries. Herein, we design a Bi 2 O 3 nanomaterial embedded in a carbon matrix. The introduction of carbon matrix can not only improve the electronic conductivity of the material, but also alleviate the volume expansion of bismuth oxide. After 100 cycles of 50 mA g−1, its specific charging capacity is 314 mA h g−1, which shows good cycle stability. By ex situ X-ray diffraction, cyclic voltammetry and charge-discharge curves, it is confirmed that the mechanism of potassium ion storage on Bi 2 O 3 @C electrode is the combination of transformation reaction mechanism and alloying reaction mechanism. [Display omitted] • A novel Bi 2 O 3 particles embedded in carbon matrix as an anode material for PIBs. • Bi 2 O 3 @C exhibits high specific capacity and cyclic stability. • The carbon matrix can buffer volume expansion of Bi 2 O 3 upon cycling. [ABSTRACT FROM AUTHOR]

Abstract: β-Bi2O3/Bi2O2CO3 composite nanosheets are synthesized via a rational heat-treatment of Bi2O2CO3 precursor. The precursor transforms to β-Bi2O3/Bi2O2CO3 composites and α-Bi2O3 phase under different calcination conditions. The photocatalytic activities are evaluated and compared through the photodegradation of methylene blue (MB) under visible-light irradiation. β-Bi2O3/Bi2O2CO3 composites exhibit much higher photodegradation activity than Bi2O2CO3 and α-Bi2O3 products. The significant enhancement is attributed to the formation of β-Bi2O3/Bi2O2CO3 heterojunctions, which is favorable for the low recombination rate of the electron–hole pairs. [Copyright &y& Elsevier]

Abstract: 3D Bi2O3 hierarchical architectures were successfully fabricated from electrodeposited bismuth (Bi) film by controlling the ramp rate and reaction temperature of thermal oxidation process. Surface morphology observations show that the 3D Bi2O3 hierarchical architectures exhibit flower-like architectures assembled by dozens of 2D nanoplates with a thickness of 25nm. Characterizations of crystal structure reveal that the 2D nanoplates are well-crystallized β-Bi2O3. Furthermore, the 3D Bi2O3 hierarchical architectures exhibit a strong and wide photoluminescence (PL) signal in the range from 500 to 900nm, with a maximum peak at 759nm. Such unique architectures are expected to be utilized as next generation of nano-scale devices, such as sensors, optics and electronics. [Copyright &y& Elsevier]

Abstract: In this work, preparation and characterization of a novel nanocomposite containing bismuth oxide (Bi2O3) nanoparticles and multiwalled carbon nanotubes (MWCNTs) was presented. Powder X-ray diffraction (XRD) studies revealed that as-synthesized Bi2O3 nanoparticles are crystalline and belong to α-phase with monoclinic symmetry. Field emission scanning electron microscopy (FESEM) study results showed that the size of Bi2O3 nanoparticles is 50nm. Energy-dispersive X-ray (EDX) spectra of as-prepared Bi2O3–MWCNT nanocomposite displayed characteristic Bi and C peaks which confirmed the incorporation of Bi2O3 with MWCNT. The prepared Bi2O3–MWCNT was also characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies. The direct electron transfer of horseradish peroxidase (HRP) has been revealed at Bi2O3–MWCNT modified glassy carbon electrode (GCE). In order to firmly anchor the HRP molecules onto Bi2O3–MWCNT matrix, a thin layer of 1% nafion (NF) solution was coated as a binder. The fabricated NF/HRP/Bi2O3–MWCNT/GCE exhibits well defined quasi-reversible redox peaks at a formal potential (E 0′) of −0.326V vs. Ag/AgCl reference electrode in 0.05M phosphate buffer solution (PBS), pH 7. NF/HRP/Bi2O3–MWCNT film remarkably lowers the over potential for H2O2 reduction than MWCNT, Bi2O3–MWCNT and unmodified GCEs. The proposed composite film exhibits quick amperometric i–t response (5s) towards H2O2 in the linear range of 8.34–28.88mM with a sensitivity of 26.54μAμM−1 cm−2. The developed NF/HRP/Bi2O3–MWCNT biosensor has a good operational stability and high selectivity towards H2O2. [Copyright &y& Elsevier]

Abstract: Colloid processing and subsequent pressure filtration were used to prepare 14.3mol% TiO2 doped Bi2O3 (Bi12TiO20, 14BTO) as solid oxide fuel cell electrolyte. Materials characterization and electrical behaviors of 14BTO samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and two-point probe DC conductivity. A pure 14BTO with a cubic sillenite single phase was prepared at the sintering process of 850°C with a high relative sintered density of 96.82%. In situ and batch-type long-term conductivity measurements at 600°C were carried out to verify the possible reason of degradation. Additional reduction–oxidation tests under CH4 atmosphere by thermogravimetric analysis (TGA) revealed possible application temperature of 14BTO electrolytes below 700°C. [Copyright &y& Elsevier]

Abstract: Two oxides, Er2O3 and Nb2O3, are used to stabilize delta-phase Bi2O3 used as electrolyte of solid oxide fuel cell. Optimization of dopant ratio and total doping concentration (TDC) is determined by X-ray diffraction, and successfully reduce the TDC (Er+Nb) to 10–15mol.%. Conductivities of different compositions are measured by two-probe method. The results show that highest conductivity appears at the minimum doping concentrations. Phase stability of ENSB samples with Er/Nb ratio of 2/1 and TDC of 10–20mol.% at 650°C up to 300h is analyzed showing two newly formed (alpha- and gamma-) phases in the samples. Degradation of conductivity at 650°C is studied in detail by DTA and TEM. The abnormity of lattice contraction of delta-phase is discussed. [Copyright &y& Elsevier]

Abstract: Bismuth oxide in δ-phase is a well-known high oxygen ion conductor and can be used as an electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). 5–10mol% Ta2O5 are doped into Bi2O3 to stabilize δ-phase by solid state reaction process. One Bi2O3 sample (7.5TSB) was stabilized by 7.5mol% Ta2O5 and exhibited single phase δ-Bi2O3-like (type I) phase. Thermo-mechanical analyzer (TMA), X-ray diffractometry (XRD), AC impedance and high-resolution transmission electron microscopy (HRTEM) were used to characterize the properties. The results showed that holding at 800–850°C for 1h was the appropriate sintering conditions to get dense samples. Obvious conductivity degradation phenomenon was obtained by 1000h long-term treatment at 650°C due to the formation of α-Bi2O3 phase and Bi3TaO7, and 〈111〉 vacancy ordering in Bi3TaO7 structure. [Copyright &y& Elsevier]

Abstract: Bi2O3 compositions were prepared to investigate the effect of rare earth metal oxides as co-dopants on phase stability of bismuth oxide. Compositions containing 9–14mol% of Y2O3 and Er2O3 were synthesized by solid state reaction. The structural characterization was carried out using X-ray powder diffraction. The XRD results show that the samples containing 12 and 14mol% total dopants had cubic structure, whereas the samples with lower dopant concentrations were tetragonal. Comparing the lattice parameters of the cubic phases of (Bi2O3)0.88(Y2O3)0.06(Er2O3)0.06 and (Bi2O3)0.86(Y2O3)0.07(Er2O3)0.07 revealed that lattice parameter decreases by increasing the dopant concentration. The XRD pattern and the powder density results indicated the formation of solid solution in the studied systems. After annealing samples with cubic phase at 600°C for various periods of time, phase transformation to tetragonal and rhombohedral occurs. [Copyright &y& Elsevier]

Abstract: The Co3O4 and Bi2O3–Co3O4 were prepared by precipitation and co-precipitation method. The samples were characterized by XRD, BET, H2-TPR, Raman, XPS and EPR. The low-temperature CO oxidation on the catalysts was also investigated. The results showed the deposition of Bi2O3 enhanced the activity and stability of Co3O4 for CO oxidation. 20wt.% Bi2O3–Co3O4 could completely convert CO as low as −89°C, and maintain the complete oxidation of CO at −75°C for 10h. XRD and Raman results showed Bi2O3 could enter the lattice of Co3O4, and promote the formation of the lattice distortion and structural defect. H2-TPR results showed that reduction of Co3O4 was promoted and the diffusion of oxygen was accelerated. XPS and EPR results showed the surface richness of Co3+ and the increase of Co2+ in 20wt.% Bi2O3–Co3O4. The formation of more Co2+ in 20wt.% Bi2O3–Co3O4 could produce structure defects and lead to the formation of more oxygen vacancy, which was suggested to play the critical role in promoting the catalytic activity and stability of 20wt.% Bi2O3–Co3O4. [Copyright &y& Elsevier]

Abstract: A novel flower-shaped Bi2O3 superstructure has been successfully synthesized by calcination of the precursor, which was prepared via a citric acid assisted hydrothermal process. The precursor and Bi2O3 were characterized with respect to morphology, crystal structure and elemental chemical state by field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It was shown that both the precursor and Bi2O3 flower-shaped superstructure were constructed of numerous nanosheets while the nanosheets consisted of a great deal of nanoparticles. Furthermore, key factors for the formation of the superstructures have been proposed; a mechanism for the growth of the superstructure has been presented based on the FESEM investigation of different growth stages. [Copyright &y& Elsevier]

Abstract: Oblique prism-like Bi2O3 have been synthesized via a simple one-step aqueous method at low temperature and ambient pressure in the presence of sodium dodecylbenzenesulfonate (SDBS). The oblique prism-like Bi2O3 have better distribution with an average diameter of 2μm and length of up to tens of micrometers. X-ray diffraction and energy-dispersive X-ray analysis (EDX) indicate that oblique prism-like Bi2O3 are monoclinic phase with high purity. The optical absorption and photoluminescence (PL) characteristics of the prepared sample were investigated. The formation mechanism has also been discussed based on experimental results. [Copyright &y& Elsevier]

Abstract: In the current work, TiO2 nanotube array was prepared via electrochemical anode method. Then the Bi2O3 nanoparticles were deposited onto the TiO2 nanotube array via dip-coating method from an amorphous complex precursor. The crystal structures were characterized via X-ray diffraction analysis. Their surface textures were observed via electron-scanning microscope. The prepared composite array electrode exhibited high photoelectrocatalytic activities towards degrading organic contaminants under visible light irradiation. High photoelectrocatalytic activities were also exhibited under UV light irradiation. The catalytic mechanism was discussed based on the analysis of electrochemical and degradation kinetics results. It is suggested a P (Bi2O3)–N (TiO2) junction was formed to increase the catalytic activates. The stability of the electrode materials was confirmed finally. [Copyright &y& Elsevier]

Abstract: Nanometric Bi2O3 powder was successfully synthesized by applying the method based on self-propagating room temperature reaction (SPRT) between bismuth nitrates and sodium hydroxide. X-ray powder diffraction (XRPD) and Rietveld''s structure refinement method were applied to characterize prepared powder. It revealed that synthesized material is a single phase monoclinic α-Bi2O3 (space group P21/c with cell parameters a =5.84605(4)Å, b =8.16339(6) Å, c =7.50788(6) Å and β =112.9883(8)). Powder particles were of nanometric size (about 50nm). Raman spectral studies conformed that the obtained powder is single phase α-Bi2O3. Specific surface area of obtained powder was measured by Brunauer–Emmet–Teller (BET) method. [Copyright &y& Elsevier]

Abstract: Hierarchical Bi2O3 spheres assembled from nanosheets with nanopore structure have been successfully synthesized by thermal decomposition of the precursor at 400°C for 3h in air, which was prepared using Bi(NO3)3·5H2O and poly(vinylpyrrolidone) (PVP) by a microwave-assisted heating method in ethylene glycol (EG) at 150°C for 10min. The morphology of Bi2O3 is similar to that of the precursor. The products were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectrometry (FT-IR), field-emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TG) and differential scanning calorimetric analysis (DSC). XRD pattern showed that the product had a high degree of crystallinity. FE-SEM micrograph indicated that hierarchical Bi2O3 spheres had sizes around 10μm. [Copyright &y& Elsevier]

This article presents the results of in situ X-ray powder diffraction, Raman spectroscopy, and electrical impedance spectroscopy of the α-phase of Bi2O3, at 0.1 MPa in the temperature range below and above the α-δ-phase transition. This work demonstrated subtle nonlinear temperature variations of the cell parameters, of the hard-mode Raman shift, and of the activation energy of electrical conductivity in the temperature range about 100-120°C below the α-δ phase transition temperature TTr ≈ 725°C in Bi2O3. At T < 600°C, the linear variation of the inverse dielectric susceptibility (χ-1) correlates well with the hard mode frequency shift Δ(ω2) of Raman A1g mode as Δ(χ-1)/Δ(ω2) ≈ 5.5 × 10-7 cm2. A structural model describing the mechanism of O2- anion distribution and electric dipole disordering in the vicinity of TTr is discussed. [ABSTRACT FROM AUTHOR]

Abstract: A strontium ferrite powder added with trace of Bi2O3 was prepared by the conventional high-temperature solid phase reaction. The effects of Bi2O3 addition on the morphology of Sr-ferrite particles fired at different temperatures and times were investigated. The results show that a small quantity of Bi2O3 addition accelerates the reaction of SrO and Fe2O3 to form SrM ferrite and obviously improves the morphology and size of the strontium ferrite particles. A possible mechanism was proposed to interpret the influence of trace of Bi2O3 addition on the morphology of strontium ferrite particles. [Copyright &y& Elsevier]

Abstract: In this work, the formation of Bi4Ti3O12 by solid state reaction from Bi2O3 and TiO2 starting powders has been studied. The Bi4Ti3O12 formation occurs through an intermediate Bi12TiO20 sillenite phase formed at temperatures sligthly over 300°C. This sillenite phase is stable up to ∼750°C, but in the presence of TiO2 reacts to form Bi4Ti3O12 at temperatures >500°C. Raman spectroscopy has been used to evidence the amorphization of TiO2, demonstrating that the Bi4Ti3O12 formation occurs through the reaction of sillenite Bi12TiO20 and TiO2. [Copyright &y& Elsevier]

Abstract: The growth of interfacial compounds between TiO2 and Bi2O3 during transient liquid phase bonding at 900, 1000 and 1100°C for various times was investigated. The microstructures and compositions of compounds in joints were analyzed by means of SEM and EPMA. It was found that the compound Bi4Ti3O12 forms initially and replaces the Bi2O3 interlayer. Bi2Ti4O11 then arises at the interface between Bi4Ti3O12 and TiO2 and the metastable Bi2Ti2O7 phase appears last at the interface between Bi4Ti3O12 and Bi2Ti4O11. The modes and activation energies of the growth of Bi4Ti3O12 and Bi2Ti4O11 were determined respectively. Holes in the middle of the joint heated at 1100°C for 24h were also found. [Copyright &y& Elsevier]

Abstract: We have developed boron co-doped Bi2O3-based erbium doped fiber and double core fiber to improve power conversion efficiency at 980nm pumping and to enhance confinement factor. We show the demonstration of short pulse amplification using Bi2O3-based Erbium doped double core fiber and compared with silica-based EDF. The short length of Bi2O3-based EDF with highly confinement factor shows highly nonlinear tolerance and superior short pulse amplification performances. [Copyright &y& Elsevier]

Abstract: Bi2O3 nanofibers with diameter of 70–200 nm were successfully prepared by electrospinning a precursor mixture of polyacrylonitrile (PAN)/bismuth nitrate, followed by calcination treatment of the electrospun polymer/inorganic composite fibers. The resulting Bi2O3 nanofibers were characterized with X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, FT-IR spectra and UV–vis diffuse reflectance spectroscopy. The Bi2O3 nanofibers calcined at 500 °C exhibited β phase, and whereas the nanofibers calcined at 550 and 600 °C both exhibited dominant β phase together with a trace amount of α phase. Photocatalytic experiments indicated that the obtained Bi2O3 nanofibers calcined at 500 °C were highly active for photodegradation of organic pollutants Rhodamine B (RB). Furthermore, the Bi2O3 nanofibers could be easily recycled without decrease of the photocatalytic activity. [Copyright &y& Elsevier]

Abstract: A simple route has been employed to prepare nanosized Bi2O3 deposited on highly ordered mesoporous carbon. The electrochemical measurements reveal that, by loading only 10% Bi2O3 on the mesoporous carbon, the specific capacitance of the composite is improved by 62%, with the maximum value reaching 232Fg−1 at a sweep rate of 5mVs−1. The specific capacitance of Bi2O3 is calculated and reaches 1305Fg−1 at 1mVs−1. It is found that the mass transfer in the framework of the crystalline oxide is still difficult in spite of its nanosize, as evidenced by the decline of the specific capacitance of the Bi2O3 with the increase of the sweep rate. The cyclic life of composite materials is also measured and the capacitance only declines 21% after 1000 cycles. [Copyright &y& Elsevier]

Abstract: The tetragonal β-phase in the binary system of (Bi2O3)1−x (Sm2O3) x was synthesized by solid-state reactions with doping Sm2O3 into the monoclinic Bi2O3, in the stoichiometric ratio of range 0.01< x <0.10. X-ray powder diffraction (XRD) data showed that the unit cell parameters of produced tetragonal-type materials increased with the increasing doping of Sm2O3. We have measured the total electrical conductivity (σ T) depending on the temperature and doping concentration. Bi2O3-based ceramic system doped with Sm2O3 showed an oxide anionic-type electrical conductivity which is increased with the increase of the dopant concentration and temperature. In the investigated system, the highest value of conductivity was observed σ T =0.029Ω−1 cm−1 at 670°C, for the composition of 7mole% Sm2O3 addition. The phase transition which manifests itself by the jump in the conductivity curves was also verified by DTA measurements which are in good agreement with the observed results of electrical conduction. The electrical conductivity curves of studied materials revealed regular increase with the temperature in the form of the Arrhenius-type conductivity behavior and the activation energies (E a) were calculated by using these graphs. [Copyright &y& Elsevier]

Abstract: Bi-doped manganese dioxide (MnO2) has been prepared from γ-MnO2 by physical admixture of bismuth oxide (Bi2O3). The doping improved the cycling ability of the aqueous cell. These results are discussed and compared with the electrochemical behavior of bismuth-free MnO2. Batteries using the traditional potassium hydroxide (KOH) electrolyte are non-rechargeable. However, with lithium hydroxide (LiOH) as an electrolyte, the cell becomes rechargeable. Furthermore, the incorporation of bismuth into MnO2 in the LiOH cell was found to result in significantly longer cycle life, compared with cells using undoped MnO2. The Bi-doped cell exhibited a greater capacity after 100 discharge cycles, than the undoped cell after just 40 cycles. X-ray diffraction and the microscopic analysis suggest that the presence of Bi3+ ions reduces the magnitude of structural changes occurring in MnO2 during cycling. Comparison with additives assessed in our previous studies (titanium disulfide (TiS2); titanium boride (TiB2)) shows that the best rechargeability behavior is obtained for the current Bi-doped MnO2. As the size of Bi3+ ions (0.96Å) is much larger than Mn3+ (0.73Å) or Mn2+ (0.67Å) they have effectively prevented the formation of non-rechargeable products. [Copyright &y& Elsevier]

Bi2O3 samples doped with several transition metal ions (M–Bi2O3, where M=VV, PbII, AgI and CoII) were synthesized using a precipitation method in the presence of sodium dodecyl benzene sulphonate (SDBS). The compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible diffuse reflection spectroscopy (UV–vis DRS) and photoluminescence (PL). The monoclinic microcrystal samples displayed different morphology and visible-light harvesting character. The photocatalytic activity of the M–Bi2O3 compounds, evaluated by the extent of decolorization of Rhodamine B under visible light, followed the order: V(V)–Bi2O3 >Pb(II)–Bi2O3 >Ag(I)–Bi2O3 >Co(II)–Bi2O3 >undoped Bi2O3. [Copyright &y& Elsevier]

Influence of sintering temperature and soaking time on densification of Bi2O3 samples doped with 25%mol Y2O3 was investigated by shrinkage and relative density measurements. Samples were sintered in air at different temperatures in the range of 800 to 1000°C for 24 hr. The results showed that samples sintered at 950°C have the maximum relative density. Several samples were sintered at 950°C for duration of 0 to 36 hr in order to evaluate the effect of soaking time on densification of samples. It was found that the samples were sintered at 950°C for 36hr had higher relative density than others did for smaller time duration X-ray diffraction (XRD) analyses detected δ -Bi2O3 as the sole stable phase in all samples. Scanning Electron Microscopy (SEM) investigation of fractured surface of the samples showed that porosities decrease by increasing of sintering temperature and grow by further increasing of temperature. [ABSTRACT FROM AUTHOR]

Abstract: Bismuth oxide thin films have been deposited by room temperature chemical bath deposition (CBD) method and annealed at 623K in air. They were characterized for structural, surface morphological, optical and electrical properties. From the X-ray diffraction patterns, it was found that after annealing a non-stoichiometric phase, Bi2O2.33, was removed and phase pure monoclinic Bi2O3 was obtained. Surface morphology of Bi2O3 film at lower magnification SEM showed rod-like structure, however, higher magnification showed a rectangular slice-like structure perpendicular to substrate, giving rise to microrods on the surface. The optical studies showed the decrease in band gap by 0.3eV after annealing. The electrical resistivity variation showed semiconductor behavior and from thermoemf measurements, the electrical conductivity was found to be of n-type. [Copyright &y& Elsevier]

Abstract: Owing to their peculiar characteristics, bismuth oxides are used in various domains, such as microelectronics, sensor technology, optical coatings, transparent ceramic glass manufacturing, etc. Bismuth oxide system exhibit high oxide ionic conductivity and have been proposed as good electrolyte materials for application, such as solid oxide fuel cell (SOFC) and oxygen sensor. Antimony doped and undoped Bi2O3 films were deposited onto glass substrate from bismuth nitrate and antimony precursor solutions. As chelating agent polyethyleneglycol (PEG) was used and the above-mentioned precursor solutions were sufficiently viscous. In the present paper, the formation of different phases belonging to Bi–O system during thermal treatments of the Bi-based films is investigated by means of spectroscopic ellipsometry (SE), polarising microscope observation, X-ray diffractometry (XRD), and infrared spectrometry (IR). The thickness and the porosity of the films were evaluated. These preparation techniques, differing mainly in precursor materials and method of deposition, lead to different quality of the resulting films. [Copyright &y& Elsevier]

Abstract: Bi2O3-doped ZnO ceramic varistors are usually sintered at temperatures near to 1200°C in the presence of a Bi-rich liquid phase, which is partially vaporized during the sintering process. Volatilization of bismuth oxide depends on the total surface area in direct contact to the reaction atmosphere and this in turn is related to the area/volume ratio of the ceramic compact. This loss of Bi2O3 has a significant role on the development of the varistor microstructure and more specifically ZnO grain growth, which is strongly enhanced by the presence of the liquid phase, should be particularly affected. In the present paper, X-ray fluorescence analysis is performed to describe the Bi2O3 vaporization profile as a function of distance to the outer surface, taking into account its influence on microstructural evolution. [Copyright &y& Elsevier]