Effect Of Bismuth Doping Research Articles

Triple synergistic effects of bismuth doping in spinel-LiMn2O4: A path to high-performance electrochemical lithium extraction from salt-lake brine

The electrochemical extraction of lithium-ion from salt-lake brine has attracted significant global interest due to the rising requirement for lithium resources. The electrochemical extraction system based on LiMn2O4 has emerged as one of the most promising methods for commercial lithium extraction. However, the dissolution of manganese in LiMn2O4 material, caused by the Jahn-Teller effect, poses a significant obstacle to achieving large lithium extraction capacity and long lifespan simultaneously. In this study, we addressed the issue by incorporating Bi3+ into the material. The resulted LMBO material displays a truncated octahedral morphology, with {100} crystal faces facilitating Li+ diffusion. Additionally, Bi3+-doping inhibits the Jahn-Teller effect and expands the Li+ diffusion pathway, thereby, enhancing the stability and Li+ diffusion rate of LMO. In particular, LMBO-2 material exhibits an excellent lithium ion diffusion rate of 2.03 × 10−9 cm2·s−1, and demonstrates outstanding Li+ release efficiency, which reaches 26.46 mg·g−1 per cycle with an average energy consumption of 2.04 Wh·mol−1 in the 30 mmol⋅L−1 simulated salt-lake brine. In simulated Zabuye brine solution, LMBO//Ag system displayed an admirably release capacity of 26.17 mg·g−1 characterized by an ultra-low Li/Na ratio, with Li/Na ratio in recovery solution reaching as high as 0.54. These significant findings advance practical applications of LiMn2O4 in brine lithium extraction processes.

Effect of bismuth doping on electrodeposition, physicochemical properties and electrocatalytic activity of lead dioxide electrodes

The bismuth (Bi)-doped PbO2 electrodes were electrodeposited from a nitric plating solution containing Pb (II) and Bi (III) ions by varying the concentrations of Bi (III). Cyclic voltammetry was used to investigate the effect of Bi (III) ions on the kinetics of PbO2 electrodeposition. It is observed that increasing Bi (III) ions in the plating solution reduces the rate of nucleation or formation of PbO2 but does not change the process mechanism. X-ray diffraction confirms that the incorporation of bismuth results in an apparent β (301) texture. Scanning electron microscopic observation reveals that the size of the PbO2-deposit particles gradually decreases by several micrometers as the doping content of Bi (III) increases from 2 to 6 mM. Linear scanning voltammograms show that the oxygen overpotential on Bi-PbO2 is much higher than on undoped PbO2 electrodes. Electrochemical degradation of the target pollutant was performed, and HPLC analysis demonstrated that Bi doping significantly improves the electrocatalytic ability of PbO2 electrodes.

Spatial Localization of Defects in Halide Perovskites Using Photothermal Deflection Spectroscopy.

Photothermal deflection spectroscopy (PDS) emerges as a highly sensitive noncontact technique for measuring absorption spectra and serves for studying defect states within semiconductor thin films. In our study, we applied PDS to methylammonium lead bromide single crystals. By analyzing the frequency dependence of the PDS spectra and the phase difference of the signal, we can differentiate between surface and bulk deep defect absorption states. This methodology allowed us to investigate the effects of bismuth doping and light-induced degradation. The identified absorption states are attributed to MA+ vibrational states and structural defects, and their influence on the nonradiative recombination probability is discussed. This distinction significantly enhances our capability to characterize and analyze perovskite materials at a deeper level.

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

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.

Effects of Bismuth Doping on the Properties of CuOx Thin Films

Effects of Bismuth Doping on the Properties of CuOx Thin Films

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.

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%).

Effect of bismuth doping and SiC nanodispersion on the thermoelectric properties of solution-processed PbTe

Thermoelectric materials are promising as they found numerous applications in electrical power generation and solid-state cooling. In the last decade, Lead Telluride (PbTe) has emerged as a potential thermoelectric candidate for electrical power generation in the medium temperature range. In the present work, we demonstrate nearly 78% enhancement in thermoelectric figure of merit (zT) of nanostructured PbTe compound through doping with bismuth and dispersing 50 nm SiC nanoparticles. Bismuth doping induces n-type conduction and improves the electrical conductivity, while the SiC nanoinclusions modulate the Seebeck coefficient by carrier energy filtering, in addition to suppressing the lattice thermal conductivity. The significant phonon scattering at multi-scale scattering centers resulted in a minimum lattice thermal conductivity (κL) of 0.69 W/m-K in Bi0.02-Pb0.98Te-8% SiC nanocomposite sample. Finally, the reduced lattice thermal conductivity in conjunction with moderate electrical conductivity and high Seebeck coefficient leads to a zTmax value of 0.32 at 590 K in the sample with 6% SiC content. Hence, the partial substitution of the host atom and the presence of a secondary phase can be another promising strategy to enhance the thermoelectric performance.

Effect of Bismuth Doping on Structural, Magnetic and Dielectric Properties of Nanocrystalline Nickel Ferrites Synthesized by Sol-Gel Technique

Effect of Bismuth Doping on Structural, Magnetic and Dielectric Properties of Nanocrystalline Nickel Ferrites Synthesized by Sol-Gel Technique

Continuous dimethyl carbonate synthesis from CO2 and methanol over BixCe1\u2212xO\u03b4 monoliths: Effect of bismuth doping on population of oxygen vacancies, activity, and reaction pathway

We evaluated bismuth doped cerium oxide catalysts for the continuous synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide in the absence of a dehydrating agent. BixCe1−xOδ nanocomposites of various compositions (x = 0.06–0.24) were coated on a ceramic honeycomb and their structural and catalytic properties were examined. The incorporation of Bi species into the CeO2 lattice facilitated controlling of the surface population of oxygen vacancies, which is shown to play a crucial role in the mechanism of this reaction and is an important parameter for the design of ceria-based catalysts. The DMC production rate of the BixCe1−xOδ catalysts was found to be strongly enhanced with increasing Ov concentration. The concentration of oxygen vacancies exhibited a maximum for Bi0.12Ce0.88Oδ, which afforded the highest DMC production rate. Long-term tests showed stable activity and selectivity of this catalyst over 45 h on-stream at 140 °C and a gas-hourly space velocity of 2,880 mL·gcat−1·h−1. In-situ modulation excitation diffuse reflection Fourier transform infrared spectroscopy and first-principle calculations indicate that the DMC synthesis occurs through reaction of a bidentate carbonate intermediate with the activated methoxy (−OCH3) species. The activation of CO2 to form the bidentate carbonate intermediate on the oxygen vacancy sites is identified as highest energy barrier in the reaction pathway and thus is likely the rate-determining step.

Influence of bismuth on microstructure, thermal properties, mechanical performance, and interfacial behavior of SAC305-xBi/Cu solder joints

This research sought to improve the properties of SAC305 solder joints by the addition of 1 and 2 wt.% Bi. The effects of bismuth doping on the microstructure, thermal properties, and mechanical performance of the SAC305-xBi/Cu solder joints were investigated. Bi-doping modified the microstructure of the solder joints by refining the primary β-Sn and eutectic phases. Bi-doping below 2 wt.% dissolved in the β-Sn matrix and formed a solid solution, whereas Bi additions equal to or greater than 2 wt.% formed Bi precipitates in the β-Sn matrix. Solid solution strengthening and precipitation strengthening mechanisms in the β-Sn matrix increased the ultimate tensile strength and microhardness of the alloy from 35.7 MPa and 12.6 HV to 55.3 MPa and 20.8 HV, respectively, but elongation decreased from 24.6% to 16.1%. The fracture surface of a solder joint containing 2 wt.% Bi was typical of a brittle failure rather than a ductile failure. The interfacial layer of all solder joints comprised two parallel IMC layers: a layer of Cu6Sn5 and a layer of Cu3Sn. The interfacial layer was thinner and the shear strength was greater in SAC305-xBi/Cu joints than in SAC305/Cu solder joints. Therefore, small addition of Bi refined microstructure, reduced melting temperature and improved the mechanical performance of SAC305/Cu solder joints.

Bismuth Doping Alters Structural Phase Transitions in Methylammonium Lead Tribromide Single Crystals.

We study the effects of bismuth doping on the crystal structure and phase transitions in single crystals of the perovskite semiconductor methylammonium lead tribromide, MAPbBr3. By measuring the temperature-dependent specific heat capacity (Cp), we find that as the Bi doping increases, the phase transition assigned to the cubic to tetragonal phase boundary decreases in temperature. Furthermore, after doping we observe one phase transition between 135 and 155 K, in contrast to two transitions observed in the undoped single crystal. These results appear strikingly similar to previously reported effects of mechanical pressure on perovskite crystal structure. Using X-ray diffraction, we show that the lattice constant decreases as Bi is incorporated into the crystal, as predicted by density functional theory. We propose that bismuth substitutional doping on the lead site is dominant, resulting in BiPb+ centers that induce compressive chemical strain that alters the crystalline phase transitions.

Effect of bismuth doping on the structural, magnetic, electrical, and thermopower behavior of lanthanum silver manganites

The structural, magnetic, electrical, and thermoelectric behaviors of lanthanum silver manganite and lanthanum bismuth silver manganite were thoroughly studied in the present work. Two polycrystalline samples, viz., La0.835Ag0.165MnO3 (LAMO) and La0.67Bi0.165Ag0.165MnO3 (LBAMO) possessing almost constant ratio of Mn3+/Mn4+ were synthesized using the wet chemical method. Phase formation was identified from powder X-ray diffraction and it has been confirmed through the structural analysis of which samples crystallize into rhombohedral symmetry with R-3C space group. Apparent changes at phase transition temperature were observed in temperature-dependent resistivity, magnetization and thermoelectric power behavior for bismuth-doped samples. In addition, an enhanced magnetoresistance was observed in LBAMO samples and is attributed to the presence of both ferromagnetic and anti-ferromagnetic states. The temperature-dependent resistivity data in the temperature range (50–300 K) were analyzed using the phase separation model. Spin-dependent scattering and electron–electron interactions were considered to explain the resistivity minimum in the low temperature region (T < 50 K). The Seebeck coefficient is positive and enhances around the transition temperature by substituting bismuth into LAMO. The high-temperature thermoelectric power data were explained in the framework of small polaron hopping mechanism while magnon drag effect dominates in the low temperature region.

Effect of bismuth doping on structural and electrical properties of 0.9(BaZr0.2Ti0.8O3)–0.1(Ba0.7Ca0.3TiO3) ceramic

The (Ba0.97Ca0.03)1−3y/2BiyZr0.18Ti0.82O3 ceramic system was prepared by the conventional solid-state sintering technique. The effect of bismuth substitution has been investigated via X-ray diffraction, Scanning electron microscopy, dielectric, electric and ferroelectric measurements. X-ray diffraction showed that these compounds crystallized, at room temperature, in tetragonal P4mm space group symmetry for BCTZ10 and BCTZ10–0.02Bi compounds and in cubic symmetry with space group Pm3‾m for y = 0.06; 0.08 and 0.1 compositions distorted perovskite structures. SEM images were used to observe the microstructure. The effect of the crystal structure change and microstructure features on the dielectric and ferroelectric properties of our new BCTZ10-yBi ceramic system has been discussed. The dependence of the permittivity on temperature indicated a crossover from a normal ferroelectric, for both BCTZ10 and BCTZ10–0.02 ceramics, to a relaxor state for 0.06 < y ≤ 0.1 composition compounds. The enhancement of the dielectric properties was marked by the shift of Tm to room temperature, the increase of the maxim of permittivity and the improvement of the relaxor behavior that characterizes optimal composition due to Bi3+ substitution. BCTZ10–0.06Bi ceramic exhibit the highest εrm', with a value of 11508 at 1 kHz, at Tm of 270 k near room temperature. Both BCZT10 and BCZT-0.02Bi ceramics exhibit a hysteresis loops signature of ferroelectric behavior at room temperature. While doped BCZT-0.02Bi show just a non linear evolution of P vs. E, the increase of the spontaneous and remnant polarizations: Ps from 0.063 μC/mm2 to 0.073 μC/mm2 and Pr from 0.028 μC/mm2 to 0.040 μC/mm2 for BCZT10 and BCZT10–0.02Bi compositions, respectively, is an evidence of the enhancement of ferroelectric properties as a result of bismuth substitution on BCZT10. The electrical properties of our new BCTZ10-yBi ceramic system may be largely tunable and could be attractive for non-volatile random access memory devices.

A study of dielectric relaxation properties of ZnFe2-xBixO4 nano Ferrites synthesized by sol-gel combustion method

A series of bismuth doped zinc nano ferrite particles with the r formula ZnBixFe2-xO4 (x = 0.00, 0.05, 0.10, 0.15, 0.20 & 0.25) were prepared by sol-gel combustion method; and these compositions were sintered at 600°C for 5 hrs. With the effect of bismuth doping, the structural properties of all prepared samples were characterized by X-ray diffraction (XRD). The X-ray diffraction spectra analyses confirm single phase cubic (FCC) spinal structure. The average crystallite size (D) of the samples found to be in the range 17-20 nm. The dielectric properties viz., dielectric constant (ε′), dielectric loss tangent (tan δ) and AC conductivity σAC) were measured at room temperature in the range 20Hz to 2MHz, which confirm the normal ferrite behavior. In the present research work, we are intended to extend dielectric relaxation studies of these samples with the help of Cole-Cole plots. The Cole-Cole plots of the bismuth doped zinc ferrites were drawn as a function of ε′ and ε″ (where, ε″=ε′ tan δ) and hence we have determined the spreading factor (β) for all the samples. It was observed that β decreases with the increase of the concentration of B2O3. It is noticed that the dielectric parameters ε′, tan δ and σAC have exhibited the similar trend. These samples may find suitable applications in electrolytic elements in battery technology.

Doping effects on optical and conductive properties of titanium dioxide in terahertz range

Terahertz time domain spectroscopy (THz-TDS) has been used to investigate the effect of bismuth doping on the refractive index, absorption coefficient, dielectric constant, and the conductivity of TiO2. Simple effective-medium approximation along with THz-TDS has been utilized for the extraction of these parameters from the composite samples. These values are increasing with dopant concentration. Moreover, the fitting of conductivity with Drude-smith model revealed that the charge carriers are localized and back scattering is the major conductivity mechanism.

Bismuth Doping Effect on Structural and Optical Properties of Nanocrystaline SnO2 Thin Films Grown by Ultrasonic Spray Pyrolysis Method

Bismuth Doping Effect on Structural and Optical Properties of Nanocrystaline SnO₂ Thin Films Grown by Ultrasonic Spray Pyrolysis Method

Bi-doped lanthanum molybdate: Enhancing the anharmonicity and reducing the thermal conductivity using Bi3+ with lone pair electrons

La2Mo2O9 has a considerably low thermal conductivity (0.95 W m−1 K−1) at 1273 K, making it an attractive material for thermal barrier coatings. To further reduce the thermal conductivity of La2Mo2O9, we focused on the anharmonicity of the lattice induced by lone pair electrons. We substituted the La3+ site of La2Mo2O9 by Bi3+, which has lone pair electrons, and studied the effect of bismuth doping on the anharmonicity and thermal conductivity of La2Mo2O9. Bismuth doping enhanced the Grüneisen parameter, which is an indicator of anharmonicity, and reduced the thermal conductivity by 24% with respect to non-doped La2Mo2O9 at 300 K by substituting with 6 mol% Bi. Theoretical predictions based on the Klemens-Callaway model with experimentally obtained Grüneisen parameters were performed to analyze the thermal conductivity; the reduction in thermal conductivity is mainly attributed to the enhanced anharmonicity provided by Bi substitution.

Magnetic and photocatalytic properties of bismuth doped KNbO3 microrods

The effect of bismuth doping on the structural, magnetic and photocatalytic properties of K1-xBixNbO3 (x = 0.0, 0.01, 0.03, 0.05 and 0.07 mol.%) microrods were studied. X-ray diffraction, Fourier transform infrared and Raman studies revealed the orthorhombic system of KNbO3. The scanning electron microscopy images display the nearly rod shape crystallites of K1-xBixNbO3. The UV–vis diffuse reflectance spectral result showed that the band gap varying between 3.13 and 2.95 eV. Photoluminescence spectra showed that the emission peaks in the visible region between 459 and 544 nm, which are mainly attributed to the oxygen vacancy present in the K1-xBixNbO3 sample. Vibrating sample magnetometer analysis revealed diamagnetic behavior of Bi doped KNbO3 samples. The BET surface area of K1-xBixNbO3 microrods varies between 9.54 and 14.48 m2g−1. The rate constant of methyl orange degradation with Bi doped samples is about 2 (x = 0.05) and 2.25 (x = 0.07) times faster when compared with that of undoped KNbO3.