Role Of Bi Research Articles

Pomelo peel biochar supported nZVI@Bi0 as a persulfate activator for the degradation of acetaminophen: Enhanced performance and degradation mechanism

Due to the contradiction between superior reaction kinetics and imperfect reproducibility of nanoscale zero-valent iron (nZVI) in persulfate oxidation systems, how to improve the reusability of nZVI while highly guaranteeing efficiency is an important but challenging matter. Hence, we took a hydrothermal-assisted carbon reduction to synthesize nZVI encapsulated with Bi being loaded on pomelo peel biochar (nZVI@Bi0/PPBC), and the results indicated that the presence of Bi could improve the reproducibility of nZVI and facilitate the removal of acetaminophen (ACE) in the persulfate (PDS) system. The degradation rate constant of the nZVI@Bi0/PPBC800 composite for ACE was approximately 1.5 times higher than that of the nZVI/PPBC800. nZVI exhibited synergistic effects with Bi on PDS activation through electron transfer. Interestingly, the Bi(0) became increasingly pure as the pyrolysis temperature increased, and the catalytic performance of ZVI@Bi0/PPBC became better. In addition,electron spin resonance and quenching experiments revealed that 1O2 and O2·− were the predominant reactive oxygen species in nZVI@Bi0/PPBC/PDS system.The nZVI@Bi0/PPBC/PDS system showed excellent oxidation ability across a broad pH range (3.0–9.0) and resisted interference from certain anions. This work reveals the possible role of Bi(0) in nZVI based PDS system, and provides an idea for the protection of nZVI.

TiO2 Catalysts Co-Modified with Bi, F, SnO2, and SiO2 for Photocatalytic Degradation of Rhodamine B Under Simulated Sunlight

The organic pollutants discharged from industrial wastewater have caused serious harm to human health. The efficient photocatalytic degradation of organic pollutants under sunlight shows promise for industrial applications and energy utilization. In this study, a modified TiO2 photocatalyst doped with bismuth (Bi) and fluorine (F) and composited with SnO2 and SiO2 was prepared, and its performance for the degradation of Rhodamine B (RhB) under simulated sunlight was evaluated. Through the optimization of the doping levels of Bi and F, as well as the ratio of SnO2 and SiO2 to TiO2, the optimal catalyst reached degradation efficiency of 100% for RhB within 20 min under simulated sunlight, with a first-order reaction rate constant of 0.291 min−1. This value was 15, 41, 6.5, and 3.3 times higher than those of TiO2/SnO2, Bi/TiO2, Bi-TiO2/SnO2, and F/Bi-TiO2/SnO2, respectively. The active species detection showed that h+ was the most crucial active species in the process. The role of Bi and F addition and SnO2-SiO2 compositing was investigated by characterization. Bi formed a chemical bonding with TiO2 by doping into TiO2. The absorbance intensity in the UV and visible light regions was improved by SnO2 and F modification. Composite with SiO2 led to a larger surface area that allowed for more RhB adsorption sites. These beneficial modifications greatly enhanced the photocatalytic activity of the catalyst.

Microstructure characterization and age hardening response of Mg-8Sn-2Al alloy with Bi, Ag addition

The effects of Bi and Ag addition on the microstructure and age hardening response of Mg-8Sn-2Al alloy were investigated in this study. The Mg2Sn phase distributed along grain boundaries was observed in as-cast Mg-8Sn-2Al alloys and disappeared after solution treatment due to the Sn dissolution into ɑ-Mg matrix. However, a majority of Mg2Sn phase disappeared and few Mg2Sn particles still existed in the solid solutioned Mg-8Sn-2Al alloys containing Bi element. Mg2Sn precipitates formed in all peak-aged alloys. And Al, Bi and Ag elements are enriched in the areas of lath-shaped and spherical Mg2Sn precipitates in peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy. Bi and Ag elements can act as heterogeneous nucleation sites and restrict the growth of precipitates to improve the age hardening response of Mg-8Sn-2Al alloy. Meanwhile, the undissolved Mg3Bi2 phase or early precipitated Mg3Bi2 phase during ageing treatment probably change the morphology and elements distribution of Mg2Sn precipitates. In addition, Ag and Bi atoms play a role on grain refinement and solution strengthening in Mg-8Sn-2Al alloy. Therefore, the micro-hardness value of peak-aged Mg-8Sn-2Al-1.5Bi-1Ag alloy increased to 69.9 HV from 47.4 HV of solid solutioned Mg-8Sn-2Al alloy. The precipitation behaviour, refined second phase, grain refinement and solute atoms synergistically made contributions to the strength improvement. The roles of Bi and Ag elements on improving age hardening response and precipitates characteristics are discussed in this study, which provides an important reference for exploring aged Mg-Sn alloys.

Business intelligence and the leverage of information in healthcare organizations from a managerial perspective: a systematic literature review and research agenda

PurposeBusiness intelligence (BI) systems and tools are deemed to be a transformative source with the potential to contribute to reshaping the way different healthcare organizations’ (HCOs) services are offered and managed. However, this emerging field of research still appears underdeveloped and fragmented. Hence, this paper aims to reconciling, analyzing and synthesizing different strands of managerial-oriented literature on BI in HCOs and to enhance both theoretical and applied future contributions.Design/methodology/approachA literature-based framework was developed to establish and guide a three-stage state-of-the-art systematic literature review (SLR). The SLR was undertaken adopting a hybrid methodology that combines a bibliometric and a content analysis.FindingsIn total, 34 peer-review articles were included. Results revealed significant heterogeneity in theoretical basis and methodological strategies. Nonetheless, the knowledge structure of this research’s stream seems to be primarily composed of five clusters of interconnected topics: (1) decision-making, relevant capabilities and value creation; (2) user satisfaction and quality; (3) process management, organizational change and financial effectiveness; (4) decision-support information, dashboard and key performance indicators; and (5) performance management and organizational effectiveness.Originality/valueTo the authors’ knowledge, this is the first SLR providing a business and management-related state-of-the-art on the topic. Besides, the paper offers an original framework disentangling future research directions from each emerged cluster into issues pertaining to BI implementation, utilization and impact in HCOs. The paper also discusses the need of future contributions to explore possible integrations of BI with emerging data-driven technologies (e.g. artificial intelligence) in HCOs, as the role of BI in addressing sustainability challenges.

The roles of Bi in InAs and InAsBi nanostructure growth

The roles of Bi in InAs and InAsBi nanostructure growth

Crack suppression in electrodeposited brass film through controlling growth stresses by co-depositing with Bi

The role of Bi in suppressing crack formation in the electrodeposited brass film is methodically examined by growing brass films from cyanide-free alkaline baths with and without Bi. Electrodeposition of the brass film with Bi produces crack-free films, whereas the brass film without Bi contains several cracks. In-situ film stress measurements by the cantilever curvature technique during the film deposition process reveal that compressive stresses are commonly generated in the film deposited with Bi, while tensile stresses are present in the brass film deposited without Bi. Both the compressive and tensile growth stresses grow with the increasing layer thickness for Bi-co-deposited and Bi-free films, respectively. Additionally, at large layer thicknesses, the growing stress in Bi-co-deposited film is highly compressive compared to the highly tensile stress developed in the Bi-free brass film. The obtained results indicate that such a change in film stress from tensile to compressive is essentially caused by grain size coarsening and stacking fault formation in the Bi-co-deposited films, because co-deposition with Bi alters the nucleation and growth of Cu-Zn grains in the electrodeposition process and the incorporation of Bi reduces the stacking fault energy of Cu-Zn alloy. This study provides a pathway to suppressing crack formation by controlling film stresses through Bi-co-deposition, thus growing crack-free brass films from environmentally friendly solutions.

Tunable Bi-bridge S-scheme Bi2S3/BiOBr heterojunction with oxygen vacancy and SPR effect for efficient photocatalytic reduction of Cr(VI) and industrial electroplating wastewater treatment

Surface plasmon resonance (SPR), oxygen vacancy modification and the construction of S-scheme heterostructure are important strategies to enhance visible-light absorption and improve photocatalytic performance. Here, a Bi-bridge S-scheme Bi2S3/BiOBr heterojunction (Bi2S3/Bi/BiOBr) with oxygen vacancies and SPR effect of Bi metal was prepared by one-pot solvothermal method for Cr(VI) reduction. The 3:10 Bi2S3/Bi/BiOBr exhibited superior visible-light photocatalytic reduction performance with 95.82 % Cr(VI) removal efficiency. Additionally, the 3:10 Bi2S3/Bi/BiOBr showed high stability and good anti-interference ability, and can effectively remove Cr(VI) from industrial electroplating wastewater with 97 % of Cr(VI) removal efficiency and residual Cr(VI) concentration of 0.304 mg/L, meeting the industrial effluent standard, which made it potentially attractive for real wastewater treatment. The enhanced photocatalytic performance of Bi2S3/Bi/BiOBr heterojunction was attributed to Bi metal SPR effect and the role of Bi as e-bridge, the presence of oxygen vacancies, the formation of internal electric field and S-scheme charge transfer, which were confirmed by various experimental results and density functional theory (DFT) calculations. This work provided theoretical and experimental reference for the construction of stable S-scheme heterojunctions with high catalytic activity and anti-interference, and a reliable solution for Cr(VI) removal from electroplating wastewater.

Forms and Roles of Bismuth in Steel: A Review

Bismuth (Bi), as a green free‐cutting metal element, has been used for the production of free‐cutting steels in the field of free‐cutting steel for a couple of decades. One of the merits of bismuth is to improve the machinability of steel, while more Bi addition to steel causes cracking of steels during thermal rolling, attributed to the formation of liquid Bi films. Due to a lack of summary, people have limited mastering the Bi‐bearing steels. Herein, the forms and roles of Bi in steel based on the literature survey are summarized. These specific reviews concentrate on the forms, mechanical properties, segregation, solidification, and solubility of Bi in steel, and the effect on grain, machinability, and thermal expansion of steel is also reviewed. This review is of great significance in advancing the understanding of Bi‐bearing steels.

Analysis and Investigation on BI Tools Utilization for Enhanced CRM and Marketing in KSA SMEs

This paper is to focus on the Adoption are companies embracing BI for small or medium businesses in KSA. Solutions need to be sought so that the available data is secured in terms of privacy, authenticity, and integrity. If they are not adopted means it is a weakness for companies: for instance, fragmentation, sales, IT, even the electronics companies... whatever. BI adoption in SMEs of KSA. The factors influencing BI, nature, the extent of influence, the role of BI in SMEs, and its relative advantages are clearly given. It is found that research studies do not focus on theories like TMA, TPA, and diffusion of innovations to a greater extent. Research scholars must orient themselves and conduct qualitative and quantitative studies in these areas. In KSA, SMEs continue to dominate and influence the country’s economic landscape and it has greater implications on the industrial performance, output, and economic growth of this country. Finally, the executive manager wants to see the report make the right decision (Decision Support System) if you don’t have BI Tools, you don’t have Strategic Planning & duration of 5 years, for example, we want to increase the sales in these nations’ hypothetical. Decision Support System: Helps the strategic companies to be competitive along time and discover weaknesses and strengths points to enhancement by analysis.

Gamma ray shielding and thermoluminescence investigation of bismuth added heavy metal oxide glasses

Nowadays, as a replacement for lead which is a toxic element, bismuth glasses are explored extensively due to their higher density for radiation attenuation applications. This work is an attempt to portray the radiation shielding and thermoluminescence response of bismuth in the borosilicate glasses of composition (60-x) B2O3– 20SiO2- xBi2O3– 12ZnO– 8BaO with x = 0, 2, 4, 6, 8, 10 and 12 mol% coded as ZBiB glasses. The estimation of theoretical values of gamma ray shielding parameters with 137Cs gamma source such as mass attenuation co-efficient, effective atomic number, half value layer and mean free path was carried out using Photon Shielding and Dosimetry software and compared with experimental results. The data naturally showed high attenuation values for ZBiB-12 glass. Higher bismuth samples were observed to possess dark brown colour and opaque nature. The applicability of such glasses for gamma dosimetry using thermoluminescence (TL) property was also examined by irradiating the glasses with 3 kGy of 1.25 MeV gamma radiation from 60Co source. The radiation created defect centers by breaking Zn–O, Bi–O, Si–O, B–O and Si–O–B bonds resulting in high intensity TL peaks. The role of Bi as thermoluminescence quenching agents has been evaluated in the present investigation. Computer Glow Curve Deconvolution was done for the TL curves to get the information regarding trapped charges such as activation energy, half-life and frequency factor. Among the high bismuth incorporated glasses, ZBiB-8 sample exhibited comparably higher TL intensity at 576.1 K with half-life of 23 years.

Tin Whisker Formation on Small Outline Transistors Assembled Using Bismuth-Containing Lead-Free Solder Alloys After Long-Term Ambient Temperature, High Humidity Storage Part 3: In-Depth Characterization and Mechanisms

With the introduction of environmental legislation such as the Restriction of Hazardous Substances (RoHS), lead (Pb)-free materials have made their way into the electronics manufacturing industry. One issue that has emerged is that Pb-free solder alloys can initiate and grow tin whiskers under specific conditions. These whiskers are thin, highly conductive filaments which have the potential to grow and can cause field failures in many applications. Most concerning with respect to tin whiskering are high reliability applications such as aerospace, automotive, and medical.
 Bismuth (Bi) is being considered for inclusion in solder alloys to replace the current industry standard (SAC 305) and provide improved thermomechanical and vibration reliability. In this paper, we discuss whisker formation of several Bi-bearing alloys after long-term (12,000 hours), ambient high humidity (25°C/85% RH) storage. Three alloys containing Bi, in addition to SAC 305 (Sn-3.0Ag-0.5Cu), were considered. These alloys were Violet (Sn-2.25Ag-0.5Cu-6.0Bi), Sunflower (Sn-0.7Cu-7.0Bi), and Senju (Sn-2.0Ag-0.7Cu-3.0Bi). The boards were fabricated with electroless nickel immersion gold (ENIG) and immersion tin (ImmSn) finishes and populated with parts having Cu and Fe42Ni alloy leads and chip parts, with half of assemblies cleaned and half cleaned and contaminated with low levels of NaCl.
 This paper is the third in a series of three in which we share more in-depth characterization of features of interest from the small outline transistor (SOT) inspection. Discussion regarding the role of Bi in the overall stress state of the joint will also be provided.

GaAsPBi epitaxial layer grown by molecular beam epitaxy

GaAsPBi is a new class of quaternary III–V compounds that extends the concept of band gap engineering on GaAs with potentials for lattice matching and excellent temperature stability. The alloy has so far been grown only by metalorganic vapor phase epitaxy and this work represents the first epitaxial results of the alloy grown by molecular beam epitaxy (MBE), an alternative technique and better suited for low-temperature processes involving Bismuth. Crystalline quality of the alloys is probed by high-resolution x-ray diffraction and photoluminescence (PL) which show that smooth and optically active films can be grown in limited parameter windows. Temperature-dependent PL shows that the 200 nm, MBE-grown GaAs0.38P0.44Bi0.18 film (the composition estimated using x-ray photoelectron spectroscopy) has a band gap temperature stability close to that of GaAsBi, and superior to GaAs. The role of Bi in the quaternary alloy is complicated: Bi not only gets incorporated into the growing film but also enhances the P molar fraction. Based on this insight, strategies for growing GaAsPBi epilayers which are lattice-matched to GaAs are described, potentially affecting many important III–V based heterostructures such as lasers, light-emitting diodes, and solar cells.

Bi aliovalent substitution in Li7La3Zr2O12 garnets: Structural and ionic conductivity effects

We report on the synthesis of cubic-phase garnet-type solid-state electrolytes based on Bi-doped Li7La3Zr2O12 (LLZO). Bi aliovalent substitution of Zr in LLZO utilizing the Pechini processing method is employed to synthesize Li7−xLa3Zr2−xBixO12 compounds. A strong dependence of the ionic conductivity on Bi content is observed, and under our synthesis and sintering conditions, a >100-fold increase over the un-doped sample is observed for x=0.75. Cubic-phase Li6La3Zr1BiO12 compounds are generated upon annealing in air in the temperature range 650 °C–900 °C. In contrast, in the absence of Bi, the cubic garnet phase of Li7La3Zr2O12 is not formed below 700 °C and a transformation to the tetragonal phase is observed at ∼900 °C for this un-doped compound. The role of Bi in lowering the formation temperature of the garnet cubic phase and in the ionic conductivity improvements is investigated in this work. We ascribe the effect of Bi-doping on ionic conductivity increments to changes in Li+-site occupancy and lattice parameters and the reduction in the formation temperature for the cubic-phase formation to rate enhancements of the solid-state reaction. To identify the site occupancy of Bi in the garnet structure, we employ synchrotron extended x-ray absorption fine structure spectroscopy. Our results indicate that Bi additions occupy the Zr-type sites exclusively, to within the accuracy of the measurements.

Origin of Luminescence in La2MoO6 and La2Mo2O9 and Their Bi-Doped Variants.

In this article, lanthanum molybdenum oxides (La2MoO6 and La2Mo2O9) and their Bi-doped derivatives were investigated as potential rare-earth-free phosphors. An X-ray diffraction analysis coupled with an EDX study confirmed the purity of the samples and the insertion of bismuth in a 1 molar % amount. Kubelka-Munk-transformed reflectance spectra clearly indicated that the insertion of Bi induces a shortening of the optical gap in La2MoO6 but has no impact on that of La2Mo2O9. Moreover, excitation and emission spectra evidenced a strong temperature quenching effect in all materials. Also, the CIEx,y parameters at 77 K are almost identical with or without Bi doping for the two host lattices. Clearly, it was shown, by combining experimental data, ab initio calculations, and the empirical positioning of absorption bands that the luminescence of the Bi-doped La2MoO6 sample is mainly related to the host lattice itself and distortions induced by La/Bi substitution. The role of the Bi3+ dopant is indirect, and the luminescence is mainly due to a Mo-O charge transfer rather than an on-site Bi3+ 3P1,0 → 1S0 transition. Concerning La2Mo2O9, there is no effect following the insertion of Bi, implying that the role of Bi is insignificant.

Time Independent Deformation of a Sn-Ag-Bi Pb-Free Solder: Stress–Strain Deformation and Yield Stress Properties

This study examined the yield stress and stress–strain deformation of the 91.84Sn-3.33Ag-4.83Bi (wt.%, abbreviated Sn-Ag-Bi) solder as part of an overall effort to develop a computational model for predicting solder joint reliability. These properties were obtained by compression testing and correlated with the role of Bi in the microstructure by scanning electron microscopy. The strain rates were 4.2 × 10−5 s−1 and 8.3 × 10−4 s−1. The test temperatures ranged from − 25°C to 160°C. Samples were tested in the as-fabricated condition or following a 24-h aging treatment at either 125°C or 150°C. The yield stress decreased monotonically with test temperature at both strain rates for Sn-Ag-Bi in the as-fabricated condition. The 125°C, 24 h aging treatment increased the yield stress measured at 25°C, 75°C, and 125°C, but left it unchanged at − 25°C and 160°C. The 150°C aging treatment caused a cross-over effect at approximately 30°C and 70°C for the 4.2 × 10−5 s−1 and 8.3 × 10−4 s−1 strain rates, respectively. Work softening was observed; its source was a combination of continuous dynamic recrystallization and the Portevin–Le Chatelier effect. The latter phenomenon was solely responsible for fluctuations in the stress–strain curves. Significant variations were observed for the Bi-rich structures as a function of aging treatment as well as following deformation, yet yield stress and plastic deformation performance remained predictable under these very high homologous temperatures.

Abstract 2207: The dual role of BI 2536, a small-molecule inhibitor that targets PLK1, in induction of apoptosis and attenuation of autophagy in neuroblastoma cells

Abstract Neuroblastoma(NB) is the most common extra-cranial solid tumor in childhood with the overall survival less than 40%. Polo-like kinase 1 (PLK1) is a serine/threonine-protein kinase expressed during mitosis and overexpressed in multiple cancers, including neuroblastoma. We found the PLK1 expression related to the outcome of NB patients. BI2536, a small molecule inhibitor against PLK1, significantly reduced cell viability in a panal of NB cell lines, with IC50 less than 100 nM. PLK1 inhibition by BI 2536 treatment induced cell cycle arrest at G2/M phase and cell apoptosis in NB cells. Realtime PCR array revealed the PLK1-regulated genes, such as BIRC7, TNFSF10, LGALS1 and DAD1 et al. Moreover, autophagy activity was investigated in the NB cells treated with BI 2536. BI 2536 treatment in NB cells increased LC3-II puncta formation and LC3-II expression. Formation of autophagosome induced by BI 2536 was observed by TEM. However, BI2536 abrogated the autophagic flux in NB cells by reducing SQSTM1/p62 expression and AMPKαT172 phosphorylation. These results provide new clues for the molecular mechanism of cell death induced by BI 2536 and suggest that BI 2536 may act as new candidate drug for neuroblastoma. Citation Format: Zhiheng Li. The dual role of BI 2536, a small-molecule inhibitor that targets PLK1, in induction of apoptosis and attenuation of autophagy in neuroblastoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2207.

Bottom-up Gold Filling of High Aspect Ratio Trenches :Toward a Mechanistic Understanding

Cu is the standard choice for the formation of multi-level 3-D interconnects allowing for microelectronic chip-stacking (1). This is predicated on the well-defined additive chemistries that drive the superconformal Cu filling of through silicon vias (TSVs) and trenches (2). To transition to Au filling of complex 3-D Si architectures for optoelectronic applications, analogous chemistries that enable preferential filling within recessed silicon features must be developed. To date the state of the art for void free Au filling has come from the use of a Pb additive in both KAu(CN)2 (3, 4) and Na3Au(SO3)2 (5) electrolytes. Both of these systems yield superconformal filling via a curvature enhanced accelerator coverage (CEAC) mechanism. However, due to the toxicity of CN- and Pb2+ containing electrolytes, alternatives must be explored. Recently, it has been demonstrated that the addition of Bi to alkaline Na3Au(SO3)2 electrolytes yields preferential bottom-up Au electrodeposition in Si trenches, with limited deposition on the free surface (6). The addition of Bi to the intrinsically suppressed Na3Au(SO3)2 electrolyte clearly accelerates deposition(6, 7). However, growth in this system does not propagate via the typical CEAC mechanism demonstrated in other accelerated systems (3). Instead the growth propagates via a mechanism more closely resembling that of S-shaped negative differential resistance (S-NDR) based on suppression breakdown, typical for suppressor based additive systems(8). This talk will explore the utilization of this Bi, Na3Au(SO3)2 electrolyte system for the bottom-up filling of high aspect ratio silicon trenches. The effect of; potential, additive concentration and electrolyte transport will be explored on the filling of features with aspect ratios ranging from 1.5 to 17. Additionally, the chemical and morphological nature of the accelerated bottoms of features, and of the passive free surface, will be compared via x-ray photoelectron spectroscopy, scanning electron microscopy and anodic stripping voltammetry to gain mechanistic insight into the role of Bi in deposition acceleration and feature localization. P. C. Andricacos, C. Uzoh, J. O. Dukovic, J. Horkans and H. Deligianni, IBM J. Res. Dev., 42, 567 (1998).T. P. Moffat, D. Wheeler, M. D. Edelstein and D. Josell, IBM J. Res. Dev., 49, 19 (2005).D. Josell, C. R. Beauchamp, D. R. Kelley, C. A. Witt and T. P. Moffat, Electrochem. Solid-State Lett., 8, C54 (2005).D. Josell, D. Wheeler and T. P. Moffat, J. Electrochem. Soc., 153, C11 (2006).D. Josell and T. P. Moffat, J. Electrochem. Soc., 160, D3009 (2013).D. Josell and T. P. Moffat, J. Electrochem. Soc., 166, D3022 (2019).I. D. E. McIntyre and W. F. Peck, J. Electrochem. Soc., 123, 1800 (1976).S.-K. Kim, J. E. Bonevich, D. Josell and T. P. Moffat, J. Electrochem. Soc., 154, D443 (2007).

Electrochemical corrosion behaviour of Sn-Zn-xBi alloys used for miniature detonating cords

Recently, Sn-Zn-Bi alloys have been reported to be the sheath material for miniature detonating cords, due to appropriate mechanical properties, ease of manufacturing, and low cost. Bi addition was found beneficial to the mechanical performance of Sn-Zn. However, limited information about the influence of Bi on the corrosion properties of Sn-Zn alloys has been provided. In this work, electrochemical corrosion behaviours of Sn-3Zn-xBi (x = 0, 1, 3, 5, 7 wt%) alloys were investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, to explore the effects of Bi on the corrosion performance of Sn-Zn alloys. The corrosion mechanism of Sn-Zn-Bi alloys was analysed through microstructure examination on the surface of alloys after corrosion measurements. Results indicated that the addition of 1 wt% Bi increased the corrosion susceptibility of the Sn-3Zn alloy, mainly attributed to the coarsened and more uniformly distributed corrosion-vulnerable Zn-rich precipitates, while further increasing the Bi contents decreased the corrosion susceptibility of Sn-3Zn-xBi alloys due to the higher fraction of nobler Bi particles serving as anodic barriers. The Sn-3Zn-7Bi possessed the best corrosion resistance among all Sn-Zn-Bi alloys investigated. The role of Bi on corrosion was considerably discussed.

Bismuth-induced band-tail states in GaAsBi probed by photoluminescence

Band-tail states in semiconductors reflect the effects of material growth and/or treatment, affect the performance of optoelectronic applications, and are hence a well-concerned issue. Dilute-Bi GaAs is considered very competitive though the role of Bi is yet to be well clarified. We in this letter investigate the effect of Bi incorporation on the band-tail states in GaAs1−xBix by excitation power- and magnetic field-dependent photoluminescence (PL) measurements at low temperatures. Three PL features are identified from a broad PL peak, which blue-shift monotonically with the increase in excitation power. None of the PL features correlate with single Bi-content free-exciton recombination, and band-tail filling rather than the donor-acceptor pair process is responsible for the power-induced blueshift. The density of band-tail states gets enhanced with the increase in the Bi incorporation level and affects the determination of Bi-induced bandgap reduction. The results indicate that joint analysis of excitation- and magneto-PL may serve as a good probe for band-tail states in semiconductors.

Photocatalytic properties of intrinsically defective undoped bismuth vanadate (BiVO4) photocatalyst: A DFT study

Monoclinic clinobisvanite BiVO4 is one of the most promising photocatalyst due to its stability, low cost, narrow band gap, and suitable valence band maximum (VBM) position. The valence band maximum of about −7.10 eV at vacuum level was observed, which is well below the redox potential of water. However, the conduction band minimum, CBM of about −4.86 eV at vacuum level, which was responsible for its low efficiency. The presence of metal (Bi or V) vacancy changed the charge density and VBM of pristine BiVO4. Our calculated results revealed that 0.04% of the intrinsic Bi or V defects enhanced p-type conductivity and hence improved photocatalytic activity than O-interstitial in pristine BiVO4. The optical properties of both pristine and intrinsically defective BiVO4 were calculated and analyzed with perspective of their photocatalytic properties. Conclusively, the role of Bi or V (metal) vacancies in pristine BiVO4 was found to be significant than O interstitials in enhancing the photocatalytic properties regarding the solar water splitting.