Bismuth Nanowires Research Articles

Lattice-dislocated bismuth nanowires formed by in-situ chemical etching on copper foam for enhanced electrocatalytic CO2 reduction

Electrochemical CO2 reduction reaction (CO2RR) to HCOOH is one of the most feasible and economical methods to achieve carbon neutrality. Bismuth (Bi), as a metal catalyst for CO2RR, is considered to have great potential for application and has been widely studied due to its high formate selectivity, low toxicity, cheapness, and abundance. Unfortunately, low current density and short electrode lifetime have hindered its progress towards practical applications. In this work, we present a method that enables the chemical etching of Bi on Cu, which is capable of spontaneously accomplishing the loading of Bi on Cu foam in the liquid phase at room temperature. Additionally, to provide more abundant catalytically active sites, twisted Bi nanowires (BiNWs) with lattice dislocations were successfully prepared on the surface of Cu foam using a three-step chemical method involving oxidation, reduction, and in-situ etching. The Cu Foam@BiNWs was found to be a highly active electrocatalyst for CO2 reduction to formate at a low applied potential, achieving a faradaic efficiency for formate (FEFormate) of 95 % and a formate partial current density of ∼ 12 mA cm−2 at −0.78 V vs. RHE (reversible hydrogen electrode). Even within such a wide potential window of −0.68 ∼ -1.08 V vs. RHE, the FEFormate is consistently above 90 %. Such exceptional CO2 reduction activity can be attributed to the distortions and lattice dislocations present in the surface BiNWs. Furthermore, the Cu Foam@BiNWs electrode demonstrated a total current density close to 100 mA cm−2 at −0.98 V in an alkaline flow cell, while maintaining excellent catalytic stability over a prolonged 30-hour period of high current density electrochemical activity, thus showing potential for advancing the industrialisation of formate production. This work emphasizes the crucial role of size-dependent catalysis and crystal defect engineering strategies in the field of electrocatalysis, elucidates the mechanism of the rate-determining step (RDS) in the electrocatalytic CO2 reduction process on the developed catalysts, which can provide valuable insights into the design and development of high performance electrocatalysts not only in CO2RR but also in other fields.

Influence of environmental conditions on the morphological evolution of bismuth oxide nanostructures via pulsed laser ablation in liquids

Bismuth oxide nanomaterials are increasingly recognized for their promising electronic and optical properties, particularly in electrochemical and biomedical applications. This study demonstrates that various bismuth oxide nanostructures can be synthesized through pulsed laser ablation in liquids (PLAL) by adjusting the concentration of dissolved gases from ambient conditions. Structural and compositional analyses were performed using x-ray diffraction, Raman spectroscopy, FTIR spectroscopy, and morphological investigations were conducted using atomic force microscopy and transmission electron microscopy. Our findings indicate that factors such as dissolved gases, laser fluence, and nanoparticle aging are crucial in determining the final structure and composition of the resulting nanomaterial. The phases observed ranged from spherical metallic bismuth nanoparticles to monoclinic bismuth oxide nanowire bundles, and orthorhombic bismuth carbonate oxide nanosheets. Dissolved gases are shown to influence not only the primary particles formed immediately after ablation, but also significantly impact the aging process of the colloid as well. Additionally, fluence plays an important role in the production of reactive oxygen species, thereby influencing the reactive pathways experienced by the ablated material and its subsequent formation into nanostructures. A notable result, emphasizing the significance of factors such as liquid environment and fluence when performing PLAL on reactive targets like bismuth, is seen in high fluence (20 J/cm2) samples under ambient conditions. These samples initially display an amalgamation of α-Bi2O3 nanowire bundles and carbonate nanosheets, which upon aging, transition to predominantly bismuth oxide nanowire bundles. This contrasts with samples produced in a saturated CO2 environment where bismuth carbonate nanosheets remain highly stable in the colloid.

Influence of High Surfactant Concentrations on the Morphology and Crystallinity of Electrodeposited Antimony and Bismuth Nanowires

Antimony and bismuth nanowires are excellent model systems to investigate the interplay of various size-dependent transport phenomena relevant for applications in thermoelectrics, spintronics, or catalysis. The properties of these nanowires can be significant influenced by size effects due to the large mean free path and Fermi wavelength of charge carriers and phonons. Since antimony and bismuth possess highly anisotropic Fermi surfaces, the transport is also strongly dependent on the crystallographic orientation. Therefore, it is very important to develop and control suitable electrodeposition processes that allow us to understand the nanowire growth and to accordingly adjust preferred orientation and morphology of the synthesized nanowires.The so called template route employed in the presented work allows to control number density, alignment, geometry, length and diameter of the nanowires. The electrolytes and plating processes influence crystallinity, crystal orientation, and morphology of the electrodeposited materials. Here, antimony and bismuth nanowires are grown by potentiostatic electrodeposition in polycarbonate etched ion-track membranes using SbCl3 and BiCl3 in aqueous electrolytes.In this talk, we will show the influence of the presence of nonionic and anionic surfactants in high concentrations in the electrolyte during the electrodeposition of Bi and Sb nanowires. The recorded current-time curves of the plating process will be presented. Systematic characterization of the nanowires by scanning- and transmission electron microscopy, and X-ray diffraction reveal a strong change in crystallinity as a function of surfactant concentration, which will be discussed in detail.

Growth of bismuth nanowires stimulated by Fe islands

Growth of bismuth nanowires stimulated by Fe islands

Experimental evidence of a size-dependent sign change of the Seebeck coefficient of Bi nanowire arrays

The electrical transport in bismuth nanowires is strongly influenced by both sample geometry and crystallinity. Compared to bulk bismuth, the electrical transport in nanowires is dominated by size effects and influenced by surface states, which gain increasing relevance with increasing surface-to-volume ratios, i.e. with decreasing wire diameter. Bismuth nanowires with tailored diameter and crystallinity constitute, therefore, excellent model systems, allowing to study the interplay of the different transport phenomena. Here, we present temperature-dependent Seebeck coefficient and relative electrical resistance measurements of parallel bismuth nanowire arrays with diameters between 40 and 400 nm synthesized by pulsed electroplating in polymer templates. Both electrical resistance and Seebeck coefficient exhibit a non-monotonic temperature dependence, with the sign of the Seebeck coefficient changing from negative to positive with decreasing temperature. The observed behavior is size-dependent and is attributed to limitations of the mean free path of the charge carriers within the nanowires. The observed size-dependent Seebeck coefficient and in particular the size-dependent sign change opens a promising avenue for single-material thermocouples with p- and n-legs made from nanowires with different diameters.

Micro Hardness Study of Macro Wire of Bismuth Samples Using Contact Model

Abstract: The micro-hardness test is often used to pre-determine the mechanical properties of a material. The Vickers method can be used for testing metals, particularly those with extremely hard surfaces. The study of the correlation between applied load and the measured value of the microhardness was carried out for Bismuth wire samples. Bismuth is a semimetal in bulk, it is not a good thermal electrical material. Bismuth nanowires (10nm) have a thermal electric figure while exhibiting semiconductor behaviour. Mechanical characterization is critical for the formation of nanowires made of various materials. The microhardness testing of bismuth wire plate samples was performed on a microscopic scale in this communication. Vicker's number variation is reported. At low indentation test loads, an indentation size effect was observed for Bismuth wire plate samples. For all samples, the variation of microhardness number (Hv) with variable loads is non-systematic. PSR ( Proportional specimen Resistance )Model, MPSR ( Proportional specimen Resistance )Model for the calculation of elastic stiffness constant C11, Wooster’s empirical relations used with obtain hardness data.

The Impact of Hydrostatic Pressure on Thermal Conductivity of Nanostructured Bi

In this study, a simulation of theoretical calculation of Lattice thermal conductivity of Bismuth bulk and nanowires with diameters of 98, 115, and 327 nm in the temperature range of 10 ‒ 300 K and pressure range of 0 ‒ 1.6 GPa was investigated. These calculations were achieved by using the Morelli Callaway model and the Clapeyron equation that both longitudinal and transverse modes are taken into account. Melting temperature, mass density, unit cell volume, mean bond length, lattice parameter, group velocity, and longitudinal and transverse Debye temperature for all transverse and longitudinal modes were calculated for each NW diameter mentioned.

Tailoring sizes and compositions of heavy pnictogen bismuth thiohalide nanorods and nanowires via heat-up method

The size and composition-controlled synthesis of pnictogen bismuth thiohalide nanocrystals is demonstrated via the injection-free heat-up method.

Polycrystalline bismuth nanowire networks for flexible longitudinal and transverse thermoelectrics.

This paper reports on the preparation and the characterization of structural, electrical and thermoelectric properties of nanocomposite films formed from three-dimensional networks of polycrystalline bismuth (Bi) nanowires (NWs). The samples were fabricated by electrodeposition within polycarbonate (PC) templates with crossed cylindrical nanopores, yielding self-supported networks of Bi crossed nanowires (CNWs) with mean diameter values ranging from 23 nm to 230 nm. Temperature changes in electrical resistance and thermopower were studied by considering electric and thermal currents flowing in the plane of the films. While the values of the Seebeck coefficient are close to those of polycrystalline Bi for diameters greater than 100 nm, a progressive decrease in thermopower appears at smaller diameters, due to an increasing contribution of surface charge carriers as the diameter decreases. Transverse thermoelectricity based on the Nernst effect was also demonstrated on a network of Bi CNWs 230 nm in diameter. Such hierarchical architectures based on Bi CNWs are extremely robust, offering a reliable solution for the next generation of flexible thermoelectric devices.

Efficient Diode Performance with Improved Effective Carrier Lifetime and Absorption Using Bismuth Nanoparticles Passivated Silicon Nanowires.

In this paper, we report a novel design of bismuth nanoparticle-passivated silicon nanowire (Bi@SiNW) heterojunction composites for high diode performances and improved effective carrier lifetime and absorption properties. High-density vertically aligned SiNWs were fabricated using a simple and cost-effective silver-assisted chemical etching method. Bi nanoparticles (BiNPs) were then anchored in these nanowires by a straightforward thermal evaporation technique. The systematic study of the morphology, elemental composition, structure, and crystallinity provided evidence for the synergistic effect between SiNWs and BiNPs. Bi@SiNWs exhibited an eight-fold enhancement of the first-order Raman scattering compared to bare silicon. Current-voltage characteristics highlighted that bismuth treatment dramatically improved the rectifying behavior and diode parameters for Bi-passivated devices over Bi-free devices. Significantly, Bi wire-filling effectively increased the minority carrier lifetime and consequently reduced the surface recombination velocity, further indicating the benign role of Bi as a surface passivation coating. Furthermore, the near-perfect absorption property of up to 97% was achieved. The findings showed that a judicious amount of Bi coating is required. In this study the reasons behind the superior improvement in Bi@SiNW's overall properties were elucidated thoroughly. Thus, Bi@SiNW heterojunction nanocomposites could be introduced as a promising and versatile candidate for nanoelectronics, photovoltaics and optoelectronics.

Tailored Bismuth Nanowires for Size-Dependent Transport Studies

Bismuth nanowires are excellent model systems to investigate the interplay of various size-dependent transport phenomena relevant for applications in thermoelectrics, spintronics or catalytics.Due to the large Fermi wavelength (lFermi~40 nm) and mean free paths of charge carriers (le and lph ~100 nm) in bismuth at room temperature, the influence of size-effects on the transport properties can be observed on nanowires of rather large diameters. Furthermore, these properties are also influenced by the fact that bismuth belongs to the class of topological insulator materials that exhibit special charge carrier transport on the material surface linked to topological states. To better understand the transport behavior, it is of utmost importance to control the nanowire properties like surface-to-volume ratio, wire diameter and wire morphology, crystal structure, material composition and, in case of nanowire assemblies, their relative alignment to one another.We present the synthesis of parallel and interconnected assemblies of bismuth nanowires with both cylindrical and conical geometry, and sizes ranging between 50 and 3500 nm. The wires are produced by electrodeposition in polymeric etched ion-track templates applying pulsed plating and an aqueous electrolyte of bismuth chloride. The electrodeposition process as well temperature-dependent Seebeck coefficient and electrical resistance measurements as a function of nanowire size and geometry will be discussed. Figure 1

In situ electrodeposition of bismuth oxide nanowires @MWNT on the carbon fiber microelectrode for the sensitively electrochemical detection of folic acid

A microminiaturized electrochemical device, BiO@CNW/CFE was fabricated based on the in situ co-electrodeposition of bismuth oxide nanowires (BiNWs) and multi-walled carbon nanotubes (MWNTs) on the surface of carbon fiber electrode (CFE). The nanostructure of BiNWs could bind MWNTs on the surface of CFE during the precipitation of bismuth at the potential of −1.1 V. The vimineous nanostructure of BiO@CNW improved the surface area and electrochemical activity of the microelectrode. With the low background noise, folic acid (FA) can be detected sensitively by BiO@CNW/CFE based on the electrochemical reduction via the method of square wave voltammetry. The linear range of FA in sodium acetate-acetic acid buffer was achieved in the range of 5.00 nM–200 nM, the detection limit was estimated to be 0.63 nM. The recoveries of FA in human serum and artificial cerebral spinal fluid were between 99% and 103%, which indicates BiO@CNW/CFE was a reliable sensor for the detection of FA in biological samples.

Bismuth nanowires with in situ shadow deposited Josephson junctions

Single crystal bismuth nanowires have been recently identified as a high-order topological system, in which the crystal “hinges” host a one dimensional helical transport channel. To date, studies on the superconducting transport in these channels have relied on an aggressive surface treatment required to strip the oxidized nanowire surface prior to deposition of a superconductor in a process that will inevitably cause some damage to the surface. In this report, we describe the growth and characterization of bismuth nanowires with in situ deposited superconducting contacts, which avoid the requirement to treat the nanowire surface for oxide removal. The described shadow deposition method may avoid damage to the bismuth nanowire surface, supplying a higher-quality platform for exploring the topological quantum transport in bismuth nanowire based Josephson junctions.

Temperature dependence of resistivity and temperature coefficient of a single-crystal bismuth nanowire based on the varying scattering mechanism

Temperature dependence of resistivity and temperature coefficient of a single-crystal bismuth nanowire was investigated considering the scattering mechanism for each Fermi pocket of the carrier using relaxation time approximation based on the Boltzmann equation. The scattering mechanism of each bismuth carrier was determined according to the relationship between the mean free path of bulk bismuth and nanowire (diameter: 595 and 345 nm). The calculation and experimental results revealed the dominant contribution of the bulk segment in the room-temperature region, influencing the scattering mechanism, whereas the dominant contribution of the wire segment was observed in the lower-temperature region owing to the substantially larger mean free path of the carrier than the wire diameter. Moreover, the temperature coefficient in the lower-temperature region was determined by the effective masses parallel and perpendicular to the wire length, verifying the unique behavior of the temperature dependence of bismuth nanowires with three-dimensional density of state.

Effects of Size Reduction on the Electrical Transport Properties of 3D Bi Nanowire Networks

Abstract3D nanowire networks are fascinating systems for future microelectronic devices. They can be handled like macroscopic objects, while exhibiting properties of nanoscale materials. Here, the fabrication of free‐standing 3D bismuth nanowire networks with well‐controlled and systematically adjusted wire diameter and interconnectivity is presented. The samples are fabricated by pulse electroplating of bismuth into the pores of ion track‐etched membranes using an aqueous electrolyte. By optimizing the growth parameters, homogeneously grown, mechanically self‐supporting and free‐standing networks without a supporting matrix are achieved. Cross‐plane Seebeck coefficient and electrical resistance values are investigated as a function of nanowire diameter and temperature. The unique characteristics of these highly interconnected and mechanically self‐supported Bi 3D nanowire networks offer exciting perspectives for their implementation in, e.g., infrared detection based on thermoelectric effects, sensing, and THz applications.

Beyond Volume Variation: Anisotropic and Protrusive Lithiation in Bismuth Nanowire.

Materials storing energy via an alloying reaction are promising anode candidates in rechargeable lithium-ion batteries (LIBs) due to their much higher energy density than the current graphite anode. Until now, the volumetric expansion of such electrode particles during lithiation has been considered as solely responsible for cycling-induced structural failure. In this work, we report different structural failure mechanisms using single-crystalline bismuth nanowires as the alloying-based anode. The Li-Bi alloying process exhibits a two-step transition, that is, Bi-Li1Bi and Li1Bi-Li3Bi. Interestingly, the Bi-Li1Bi phase transition occurs not only in the bulk Bi nanowire but also on the particle surface showing its characteristic behavior. The bulk alloying kinetics favors a Bi-(012)-facilitated anisotropic lithiation, whose mechanism and energetics are further studied using the density functional theory calculations. More importantly, the protrusion of Li1Bi nanograins as a result of anisotropic Li-Bi alloying is found to dominate the surface morphology of Bi particles. The growth kinetics of Li1Bi protrusions is understood atomically with the identification of two different controlling mechanisms, that is, the dislocation-assisted strain relaxation at the Bi/Li1Bi interface and the short-range migration of Bi supporting the off-Bi growth of Li1Bi. As loosely rooted to the bulk substrate and easily peeled off and detached into the electrolyte, these nanoscale protrusions developed during battery cycling are believed to be an important factor responsible for the capacity decay of such alloying-based anodes at the electrode level.

Growth Habits of Bismuth Selenide (Bi2Se3) Layers and Nanowires over Stranski–Krastanov Indium Arsenide Quantum Dots

Bismuth selenide layers and nanowires have been grown by molecular beam epitaxy on self-assembled Stranski–Krastanov InAs quantum dots of different sizes and densities on GaAs substrates. The size ...

Correction to: Growth mechanism identification of sputtered single crystalline bismuth nanowire

Correction to: Growth mechanism identification of sputtered single crystalline bismuth nanowire

Growth mechanism identification of sputtered single crystalline bismuth nanowire

Single crystalline bismuth nanowire is recently considered as one of the most attractive low dimensional materials for the exploration of exotic higher-order topological properties. However, its growth mechanism by sputtering, which is regarded as one of the most cost-effective and simplest method, is still unrevealed. In this work, a bismuth nanowire growth model based on surface diffusion driven by chemical potential difference among crystal facets is proposed for sputtering method. The morphology evolution of bismuth nanowires is captured for the first time, and three corresponding growth stages are clearly discriminated. The possible self-catalyzed, stress-driven, and screw dislocation-driven nanowire growth mechanisms are precluded separately based on the theoretical and experimental data. The thoroughly understanding of growth mechanism is fundamental and necessary for fabrication of size-controllable bismuth nanowires and may pave the way for the preparation of other low dimensional materials and the investigation of novel physics.

Morphology effects of bismuth catalysts on electroreduction of carbon dioxide into formate

A study of understanding the effect of morphology during the electrochemical CO2 reduction on bismuth catalysts is presented. Three types of pristine bismuth catalysts with designed morphologies were synthesized via the hydrothermal method and their catalytic activity and selectivity towards electrochemical CO2 reduction were analyzed and discussed. In comparison with bismuth nanowires and nanospheres, two-dimensional bismuth nanosheets with a thickness of 10 nm show enhanced selectivity for formate formation due to the highest (012) facet texture coefficient value. The highest Faradaic efficiency of 85% for the formation of formate was achieved at −0.85 V vs. RHE and a stability electrolysis test conducted at the same potential showed only 8% activity loss over 8 h. These results reveal the importance of the nanoengineering strategy for developing the next generation of non-precious metal electrocatalyst for CO2 reduction.