Doped Bismuth Research Articles

Adsorption performance study of bismuth-doped ZIF-8 composites on radioactive iodine in the vapor and liquid phases

Radioactive iodine generated from nuclear waste and nuclear accidents can cause serious hazards to the environment and human body. In this study, bismuth-doped ZIF-8 composites (Bi2O3@ZIF-8) were synthesized by in situ synthesis at room temperature to study their adsorption of iodine in gaseous state and in solution. The Bi2O3@ZIF-8 composites were characterized and analyzed by means of tests. Bi2O3@ZIF-8 exhibited high specific surface area and contained abundant microporous structures. However, when the bismuth doping amount reached 10%, 10%-Bi2O3@ZIF-8 appeared mesoporous. The specific surface area of 1%-Bi2O3@ZIF-8, 5%-Bi2O3@ZIF-8 and 10%-Bi2O3@ZIF-8 could reach 1110.6 m2/g, 973.21 m2/g and 927.82 m2/g, respectively. The adsorption of gaseous iodine by 5%-Bi2O3@ZIF-8 reached equilibrium after 3.5 h with the maximum adsorption capacity of 298 wt%. And the maximum adsorption capacity of iodine in solution was 751.4 mg/g. The effects of the initial concentration of the solution, reaction temperature and contact time on the adsorption process were investigated. The adsorption of Bi2O3@ZIF-8 on iodine was consistent with the pseudo-second-order kinetics and the Langmuir model. The results of thermodynamic studies indicated that the adsorption of iodine by Bi2O3@ZIF-8 was spontaneous and exothermic. This study provides a reference for the synthesis of metal organic framework-based materials and provides theoretical guidance for the removal of practical radioactive iodine.

Solid state pelletizing for the synthesis of new Bi-doped strontium molybdate and its development as a photocatalytic precursor for Rhodamine B degradation

At present, climate change, urbanization and globalization are the main factors that affect water quality, the primary vehicle for the translocation and permanence of emerging pollutants, resulting in a danger to human health and the environment. The scheelite-type compounds have been investigated owing to their interesting photocatalytic properties in water purification trough the removal of different organic and inorganic pollutants. In this article a method solid state for doping of bismuth(III) in systems Sr1−3xBi2xΦxMoO4 with (0 ≤ x ≤ 0.225) were obtained and, likewise its pelletizing process. Subsequently, these new materials were spectroscopically characterized with photocatalytic properties and finally is describe its development as oxidant against Rhodamine B. This work can be used for the synthesis of new Bi-doped strontium molybdates, which the best photochemical properties are chosen and, in turn, it is experimentally shown how can favor its absorption in the visible region. These electronic properties can be used in near studies, for to compressive the role of bismuth(III) in sheelite as photocatalyst and, to implement its use in the degradation of persistent pollutants that affect the world's water resources.•The doping of bismuth(III) for systems Sr1−3xBi2xΦxMoO4 modified the GAP absorption and this catalytic properties using this new solid state method.•The degradation of Rhodamine B for systems Sr1−3xBi2xΦxMoO4 as case study using of this methodology allows multiple applications associated with climate change such as: the degradation of emerging pollutants and the sensitization of semiconductors with solar claims.•The role of bismuth(III) in these systems can be harnessed to design similar materials with photocatalytic properties.

Investigating the effects of bismuth doping on the structural, optical, and electrical properties of Cu2ZnSnS4 thin films for photovoltaic applications

Investigating the effects of bismuth doping on the structural, optical, and electrical properties of Cu2ZnSnS4 thin films for photovoltaic applications

High NIR Reflectance and Photocatalytic Ceramic Pigments Based on M-Doped Clinobisvanite BiVO4 (M = Ca, Cr) from Gels.

Clinobisvanite (monoclinic scheelite BiVO4, S.G.I2/b) has garnered interest as a wide-band semiconductor with photocatalyst activity, as a high NIR reflectance material for camouflage and cool pigments and as a photoanode for PEC application from seawater. BiVO4 exists in four polymorphs: orthorhombic, zircon-tetragonal, monoclinic, and scheelite-tetragonal structures. In these crystal structures, V is coordinated by four O atoms in tetrahedral coordination and each Bi is coordinated to eight O atoms from eight different VO4 tetrahedral units. The synthesis and characterization of doped bismuth vanadate with Ca and Cr are studied using gel methods (coprecipitated and citrate metal-organic gels), which are compared with the ceramic route by means of the UV-vis-NIR spectroscopy of diffuse reflectance studies, band gap measurement, photocatalytic activity on Orange II and its relation with the chemical crystallography analyzed by the XRD, SEM-EDX and TEM-SAD techniques. The preparation of bismuth vanadate-based materials doped with calcium or chromium with various functionalities is addressed (a) as pigments for paints and for glazes in the chrome samples, with a color gradation from turquoise to black, depending on whether the synthesis is by the conventional ceramic route or by means of citrate gels, respectively; (b) with high NIR reflectance values that make them suitable as fresh pigments, to refresh the walls or roofs of buildings colored with them; and (c) with photocatalytic activity.

Growth and Characterization of Pure and Yb- Doped Bismuth Zinc Oxyborate (Bi2ZnOB2O6)

Growth and Characterization of Pure and Yb- Doped Bismuth Zinc Oxyborate (Bi2ZnOB2O6)

Effect of Bismuth Doping on Noise Figure of Er-Doped Silica Fiber

We investigate the spectral and amplification characteristics of Bi/Er co-doped fiber (BEDF) and Er-doped fiber (EDF), prepared by atomic layer deposition (ALD). BEDF features a noise figure (NF) below 5.2 dB, the bandwidth with NF less than 4 dB is approximately 23 nm (1560–1583 nm), and that with a gain exceeding 25 dB is approximately 42 nm (1525–1567 nm). The quantum conversion efficiency (QCE) of BEDF at 1550 nm is 72.1% at a pump power of 300 mW. The saturated output power of BEDF at 1550 nm is 21.4 dBm. Raman spectra indicate that the maximum phonon energy of BEDF is lower than that of EDF. The fluorescence lifetime of the BEDF is 11.64 ms, which is longer than that of the EDF. These results show that co-doping with Bi ions could increase the fluorescence lifetime of Er <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3+</sup> , reduce the NF, and improve the QCE and saturated output power. Therefore, this type of BEDF is a promising gain medium for optical amplifiers and lasers.

Synergistic engineering of doping and vacancy in K0.5Na0.5NbO3-based photochromic ceramics to boost luminescent readout ability

Photon-mode ultracapacity storage media made of inorganic photochromic luminescent materials are highly anticipated, and widely explored in the development of new optical data storage (ODS) technologies. Despite some recent breakthroughs, the optical storage capacity of defect-rich photochromics is still limited to low luminescent readout abilities. Herein, oxygen vacancy rich and bismuth doped K0.5Na0.5NbO3:Eu3+ ceramics were designed, and synergistically boost the luminescence intensity, photochromic efficiency, and luminescent modulation properties, then effectively improving the luminescence readout abilities. The luminescence modulation ratio reaches up to 97.5% from 68.4% with the increase of oxygen vacancy concentrations due to hetero-valent bismuth doping, accompanied by high photochromic efficiency (35.7% from 21.9%) and excellent reproducibility. These results demonstrate that the synergistic engineering of oxygen vacancy and doping is a promising strategy for obtaining high-performance photochromic materials.

Greatly boosted photocatalytic N2-to-NH3 conversion by bismuth doping in CdMoO4: Band structure engineering and N2 adsorption modification

This work enhances the photocatalytic N2 immobilization performance of CdMoO4 through Bi doping. The doped Bi element exists in the presence of Bi3+ and substitutes the position of Cd2+. The particle size of CdMoO4 is greatly decreased due to Bi doping. Additionally, it narrowed the band gap, reduced the work function, and elevated the conduction band, which endowed the Bi-doped CdMoO4 with a stronger ability in generating and separating charge carriers than CdMoO4. Density function theory (DFT) calculations further indicated that N2 has stronger adsorption at the unsaturated Mo sites of Bi-doped CdMoO4 due to the interactions between the 2π* orbital of N2 with the d orbital of Mo. The combination of these changes allows Bi-CdMoO4 to exhibit excellent photocatalytic N2-to-NH3 performance. The NH3 generation rate of optimal Bi-CdMoO4 reaches 7.2 times that of CdMoO4. This work may show some light on the preparation of novel photocatalysts for N2-to-NH3 conversion.

Structural and magnetic analysis of pure and rare earth doped bismuth ferrites (BFO)

Structural and magnetic analysis of pure and rare earth doped bismuth ferrites (BFO)

Effects of Bismuth Doping on the Properties of CuOx Thin Films

Effects of Bismuth Doping on the Properties of CuOx Thin Films

Aggregation of ODC(I) and POL Defects in Bismuth Doped Silica Fiber

First-principles calculations were used to simulate the aggregation of the peroxy chain defect POL and the oxygen vacancy defect ODC(I). Defect aggregation's electronic structure and optical properties were investigated. The two defects were most likely to accumulate on a 6-membered ring in ortho-position. When the two defects are aggregated, it is discovered that 0.75 ev absorption peaks appear in the near-infrared band, which may be brought on by the addition of oxygen vacancy defect ODC(I). We can draw the conclusion that the absorption peak of the aggregation defect of ODC(I) defect and POL is more prominent in the near infrared region and visible light area than ODC(I) defect and POL defect.

Iron–doped bismuth oxybromides as visible−light−responsive Fenton catalysts for the degradation of atrazine in aqueous phases

Pesticides and its degradation products, being well–known residues in soil, have recently been detected in many water bodies as pollutants of emerging concerns, and thus there is a contemporary demand to develop viable and cost–effective techniques for the removal of related organic pollutants in aqueous phases. Herein, a visible−light−responsive Fenton system was constructed with iron–doped bismuth oxybromides (Fe–BiOBr) as the catalysts. Taking the advantage of sustainable Fe(III)/Fe(II) conversion and optimized H2O2 utilization, the optimal Fe–BiOBr–2 catalyst showed an excellent atrazine removal efficiency of 97.61% in 120 min, which is superior than the traditional homogeneous Fenton and the majority of heterogeneous processes documented in the literature. In this photo–Fenton system, hydroxyl (·OH) and superoxide (·O2–) radicals were dominant active species contributed to the oxidative degradation of atrazine. Due to the production of various active radicals, five degradation pathways were proposed based on the identification of intermediates and degradation products. Overall, this work not only demonstrates a fundamental insight into creating highly efficient and atom economic photo−Fenton systems, but also provides a complementary strategy for the treatment of organic pollutants in water.

Ag2–3xBixS Quantum Dots as Single-Component Theranostic Agents for Second Near-Infrared Fluorescence Imaging-Guided Photothermal Therapy

Silver sulfide (Ag2S) nanomaterials are being researched increasingly because of their multifunctional potential in the second near-infrared (NIR-II) region (1000–1500 nm). Here, we report Ag2–3xBixS quantum dots (Ag2–3xBixS QDs) as single-component theranostic nanomaterials for NIR-II fluorescence imaging and synchronous photothermal therapy. Bismuth doping in Ag2S QDs leads to a fluorescence red shift to the NIR-II region and simultaneously enhances the photothermal conversion efficiency to 58.9%, which can be ascribed to the altered band gap introduced by bismuth doping. This Ag2S-based NIR-II theranostic agent can be synthesized in a controlled manner by an albumin biomineralization method under mild conditions. The encapsulation of the biomacromolecular albumin endowed Ag2–3xBixS QDs with greatly strengthened biocompatibility and stability. The survival rate of cancer cells was only 13% after irradiation with an 808 nm laser at a density of 1.2 W cm–2 for 10 min. Meanwhile, in vivo experiments have confirmed the desirable NIR-II fluorescence imaging capability of Ag2–3xBixS QDs. Thus, this study provides a highly efficient single-component theranostic agent with great promise for application in the field of precision theranostics.

Study on the luminescence characteristics of Tb3+-doped TeO2-Bi2O3-BaF2 glass for blue-green laser emission

In this study, we prepared Tb3+-doped bismuth tellurite glasses by a high-temperature melting method. The matrix glass was characterized by higher thermal stability (ΔT = 102 °C) and lower maximum phonon energy (614 cm−1). Based on absorption spectra, Judd-Ofelt analysis revealed the spontaneous radiation transition probability (269.34 s−1) and fluorescence branching ratio (41.55%) of 5D4→7F5 transition. The luminescence peaks of the samples were located at 486 nm and 545 nm blue-green bands. Meanwhile, the luminescence intensity increased with the increase of Tb3+ concentration and reached the maximum at 4mol% Tb4O7. In addition, emission cross-section and gain coefficients were calculated in blue wavelength range, the maximum values were 2.01 × 10−22 cm−1 and 2.92 cm−1, respectively. Combining all the above results, Tb3+ doped bismuth tellurite glass had potential application value in the field of blue-green communication.

Tuning the morphology, stability and optical properties of CsSnBr3 nanocrystals through bismuth doping for visible-light-driven applications.

In this investigation, we have demonstrated the synthesis of lead-free CsSnBr3 (CSB) and 5 mol% bismuth (Bi) doped CSB (CSB'B) nanocrystals, with a stable cubic perovskite structure following a facile hot injection technique. The Bi substitution in CSB was found to play a vital role in reducing the size of the nanocrystals significantly, from 316 ± 93 to 87 ± 22 nm. Additionally, Bi doping has inhibited the oxidation of Sn2+ of CSB perovskite. A reduction in the optical band gap from 1.89 to 1.73 eV was observed for CSB'B and the PL intensity was quenched due to the introduction of the Bi3+ dopant. To demonstrate one of the visible-light-driven applications of the nanocrystals, photodegradation experiments were carried out as a test case. Interestingly, under UV-vis irradiation, the degradation efficiency of CSB'B was roughly one order lower than that of P25 titania nanoparticles; however, it was almost five times higher when driven by visible light under identical conditions. The water stability of CSB'B perovskite and suppression of the oxidative degradation of Sn were confirmed through XRD and XPS analyses after photocatalysis. Moreover, by employing experimental parameters, DFT-based first-principles calculations were performed, which demonstrated an excellent qualitative agreement between experimental and theoretical outcomes. The as-synthesized Bi-doped CSB might be a stable halide perovskite with potential in visible-light-driven applications.

Effect of bismuth doping on the crystal structure and photocatalytic activity of titanium oxide.

The doping of TiO2 with metals and non-metals is considered one of the most significant approaches to improve its photocatalytic efficiency. In this study, the photodegradation of methyl orange (MO) was examined in relation to the impact of Bi-doping of TiO2. The doped TiO2 with various concentrations of metal was successfully synthesized by a one-step hydrothermal method and characterized using X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM), and UV-vis spectroscopy. The XRD results revealed that the anatase phase, with an average crystallite size of 16.2 nm, was the main phase of TiO2. According to the anatase texture results, it was found that the doping of TiO2 increased the specific surface area for Bi2O3@TiO2 without a change in the crystal structure or the crystal phase of TiO2. Also, XPS analysis confirmed the formation of Ti4+ and Ti3+ as a result of doping with Bi. The activities of both pure TiO2 and Bi-doped TiO2 were tested to study their ability to decolorize MO dye in an aqueous solution. The photocatalytic degradation of MO over Bi2O3@TiO2 reached 98.21%, which was much higher than the 42% achieved by pure TiO2. Doping TiO2 with Bi increased its visible-light absorption as Bi-doping generated a new intermediate energy level below the CB edge of the TiO2 orbitals, causing a shift in the band gap from the UV to the visible region, thus enhancing its photocatalytic efficiency. In addition, the effects of the initial pH, initial pollutant concentration, and contact time were examined and discussed.

Effect of bismuth doping on zircon-type gadolinium vanadate: Effective electrocatalyst for determination of hazardous herbicide mesotrione

Pesticides are used to promote the growth of plants and crops by killing weeds and other pests. On the other hand, overused and unused pesticides can leach into groundwater and agricultural lands, easily contaminating water, air, and soil resources. Doping with metal ions is an effective method to improve the catalytic activity of potential electrode materials. In the present study, an electrochemical sensor based on Bi3+-doped gadolinium vanadate nanoparticles (GVB NPs) was fabricated for sensitive and selective detection of harmful pesticide mesotrione (MST). The crystalline nature, functional groups, and elemental composition of the prepared electrocatalysts were confirmed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Field-emission scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HR-TEM) showed that the undoped gadolinium vanadate had a rice-like nanostructure and was designated as GV NRs, while GVB had the morphology of nanoparticles. The fabricated electrode exhibited a well-resolved MST reduction peak in cyclic voltammetry and linear sweep voltammetry (LSV). Bismuth doping effectively enhanced the MST reduction and produced a stronger cathodic current response than bare and GV NRs-modified GCE. Moreover, GVB NPs/GCE show a nanomolar detection limit of 45 nM with a sensitivity of 0.43 μA μM−1 cm−2. The proposed sensor showed good repeatability, reproducibility, and stability in LSV analysis. The fabricated MST sensor was successfully applied to the analysis of real samples (river water and corn) with good recovery results.

Mechanosynthesis of Mesoporous Bi-Doped TiO2: The Effect of Bismuth Doping and Ball Milling on the Crystal Structure, Optical Properties, and Photocatalytic Activity

In this work, we reported obtaining mesoporous Bi-doped TiO2 by mechanosynthesis and bismuth loading of 0%, 1%, 3%, 5%, and 10% (milled TiO2, TiO2 Bi 1%, TiO2 Bi 3% TiO2 Bi 5%, and TiO2 Bi 10%, respectively). The effect of bismuth doping and ball milling on the crystal structure, optical properties, and photocatalytic performance of Bi-doped TiO2 mesoporous samples under UV, visible, and sun irradiation was investigated. According to the results of the Rietveld refinement, the estimated chemical formulas for the TiO2 Bi 1%, TiO2 Bi 3%, TiO2 Bi 5%, and TiO2 Bi10% samples were Ti0.99Bi0.01O2, Ti0.97Bi0.03O2, Ti0.96Bi0.04O2, and Ti0.91Bi0.09O2 respectively. The incorporation of Bi into the TiO2 lattice causes the crystallite size to decrease and, consequently, the absorption spectrum of TiO2 to extend into the visible region of the electromagnetic spectrum, resulting in a lower band gap (Eg) value. Bi-doped TiO2 mesoporous samples had Eg values of 2.90 eV, 2.83 eV, 2.77 eV, and 2.70 eV for the TiO2 Bi 1%, TiO2 Bi 3%, TiO2 Bi 5%, and TiO2 Bi 10% samples, respectively. Photocatalytic removal of methylene blue (MB) data fit well for second-order kinetics. Photocatalytic activity increase followed the order of TiO2 Bi 5% &gt; TiO2 Bi 10% &gt; TiO2 Bi 3% &gt; TiO2 Bi 1% &gt; pristine TiO2. The TiO2 Bi 5% sample exhibited excellent photocatalytic performance for MB photodegradation under natural sunlight (89.2%).

Magnetoelectric, and dielectric based switching properties of co-doped BiFeO3 for low energy memory technology: A first-principles study

First-principles calculations are carried out to grow half-metallicity, tune dielectric and magnetoelectric properties of pure and doped bismuth ferrite BiFeO3 (BFO) with lanthanum (La) at A-site and cobalt (Co) at B-site as mono- and co-dopants. These calculations are performed in the Cambridge Serial Total Energy Package (CASTEP) code using ultra-soft pseudopotential (USP). A large band gap has been observed in the pure rhombohedral phase. The Co impurity atom is more favorable to decrease the band gap while La pushes the BFO towards half-metallic behavior, which develops 100% polarization in all doped BFO systems. From the dielectric response of BFO, high spin current density <s> of 8.7 × 103 A/m2 and charge current density (j) of 6.3 × 10–11 A/m2 have been observed in the La doped system. In the case of magnetic properties, the strong magnetization (M) 32.13 MA/cm2 and the large magnetoelectric coupling coefficient of 6.72× 10−6 s/m have been observed in co-doped BFO.

Improved electrochemical performance of rare earth doped Bi1−xMxPO4 (x = 0, 0.15; M = La, Ce, Sm) Nanostructures as electrode material for energy storage applications

Bismuth phosphate is one of the emerging electrode materials for various energy storage applications. Here we analyzed the electrochemical behavior of doped bismuth phosphate nanostructures with La, Ce, and Sm synthesized using a hydrothermal route. The electrochemical performance of these rare earth-doped bismuth phosphate nanostructures has never been reported earlier. The structural and morphological analysis confirms the hexagonal and monoclinic phases. High–resolution X-ray photoelectron spectroscopy (XPS) spectra confirm the oxidation states of the synthesized samples. Various doping elements play a significant role in tuning the electrochemical property of working electrodes for super cappetry/energy storage applications. All the pure and doped working electrodes exhibited the high potential window of 1.4 V in an aqueous electrolyte which is an important parameter to enhance the energy density for the device applications. The specific capacity is found to be maximum for Sm-doped bismuth phosphate nanostructures, i.e., 1135 Cg−1at the current density of 1 Ag−1. The cycle stability test was performed for the Sm-doped bismuth phosphate sample for 4000 cycles with 92 % retention. The results analysis revealed that Sm doped bismuth phosphate nanostructures as a electrode material has great potential for practical utility in energy storage applications.