Bismuth Electrode Research Articles

On the compatibility of high mass loading bismuth anodes for full-cell sodium-ion batteries.

Metallic bismuth is here studied as an anode material for sodium-ion batteries. The details of electrochemical redox reactions, rate performance and cycled life were investigated using relatively high mass loading electrodes in two- and three-electrode full-cells. It demonstrated that the rate capability of bismuth anodes with high mass loading are not as good as indicated in previous literatures where low mass loading electrodes were used. It also indicated that the resistances causing a faltering rate performance may be connected to a loss in particle contact during desodiation. Efforts were also made to study the different electrochemical processes that occur during early cycles. Less advantageous characteristics of bismuth electrodes are also discussed. For example, several different electrolyte solutions were tested for compatibility with the bismuth system, where only glyme-based solutions seemed to facilitate robust cycling.

Study by Optical Spectroscopy of Bismuth Emission in a Nanosecond-Pulsed Discharge Created in Liquid Nitrogen.

Time-resolved optical emission spectroscopy of nanosecond-pulsed discharges ignited in liquid nitrogen between two bismuth electrodes is used to determine the main discharge parameters (electron temperature, electron density and optical thickness). Nineteen lines belonging to the Bi I system and seven to the Bi II system could be recorded by directly plunging the optical fibre into the liquid in close vicinity to the discharge. The lack of data for the Stark parameters to evaluate the broadening of the Bi I lines was solved by taking advantage of the time-resolved information supported by each line to determine them. The electron density was found to decrease exponentially from 6.5 ± 1.5 × 1016 cm−3 200 ns after ignition to 1.0 ± 0.5 × 1016 cm−3 after 1050 ns. The electron temperature was found to be 0.35 eV, close to the value given by Saha’s equation.

SENSORS BASED ON TRACK-ETCHED MEMBRANES FOR ELECTROCHEMICAL DETECTION OF CADMIUM IONS

Among electrochemical detection methods, square-wave anodic voltammetry (SW-ASV) is the most popular. However, this method has a number of limitations, for instance, mercury or bismuth electrodes are usually used as a working electrode, which are highly toxic substances. This article is devoted to the study of the use of track-etched membranes based on polyethylene terephthalate as a basis for electrochemical sensors. The modification of the surface of membranes was carried out by the method of photoinitiated graft polymerization of methacrylic acid. Magnetron sputtering with a mask was used to obtain electrodes on both sides of the membrane. The sensor has been tested for sensing toxic cadmium ions in a concentration range of 0.5 to 12.5 mg/L.

Besides the Capacitive and Diffusion Control: Inner‐Surface Controlled Bismuth Based Electrode Facilitating Potassium‐Ion Energy Storage

AbstractOne of the major challenges of potassium‐ion hybrid capacitors (PIHCs) is to explore favorable anode materials with fast reaction kinetics to match the cathodes. Here, an “inner‐surface” controlled electrochemistry mechanism based on bismuth electrode is proposed and in‐depth studied, which is different from the capacitive or diffusion controlled electrode. Such inner‐surface controlled electrochemistry performance gives a high K ion diffusion ability under not only room temperature (RT) but also low temperature (LT). In this study, a kind of conjunct‐like bismuth nanoparticle (CBN) is fabricated to model such an advantage. The CBN anode for PIBs displays ultra‐long cycling stability and excellent rate capability, especially with a reversible capacity of 212.9 mAh g−1 at 30 A g−1 after 5000 cycles under RT. At −20 °C, the CBN anode achieves a capacity of 191.9 mAh g−1 at 10 A g−1 after 10 000 cycles. Coupling with activate carbon cathode, the as‐assembled PIHCs deliver high energy/power densities (111.8 Wh kg−1/412.8 W kg−1 and 29 Wh kg−1/14 312.6 W kg−1), which outperforms those of previously reported PIHCs and other hybrid capacitors. The study provides a new understanding of the energy storage mechanism for bismuth‐based electrodes and accelerates the development of advancing potassium ion storage devices, especially at LT.

Refinement of the Phase Diagram of the Bi-Te System and the Thermodynamic Properties of Lower Bismuth Tellurides

Alloys of the system Bi-Te obtained by long-term thermal annealing of samples quenched from 1000 K were studied by differential thermal analysis, x-ray phase diffraction, and scanning electron microscopy methods, as well as by electromotive forces measurements (EMF) of concentration cells relative to a bismuth electrode. A new refined version of the phase diagram which reflects the compounds Bi2Te3, Bi4Te5, Bi8Te9, BiTe, Bi4Te3, Bi2Te, and Bi7Te3 with practically constant compositions was constructed. It was found that all of these compounds, except for Bi2Te3, melt with decomposition by peritectic reactions. Based on powder diffraction patterns, the types and parameters of the crystal lattices of these compounds were determined. The EMF measurements were used to determine the partial molar functions of bismuth in the alloys and the standard integral thermodynamic functions of bismuth tellurides.

Kinetic Properties and Electrochemical Separation of Uranium on Liquid Bismuth Electrode in LiCl–KCl Melt

Electrochemical studies of UCl3 and LnCl3 (Ln: La, Ce, Pr, Nd) in LiCl–KCl melt were performed on inert tungsten and reactive bismuth electrodes. Galvanostatic pulse (GP) and electrochemical impedance spectroscopy (EIS) were carried out to investigate the exchange current density j0 of UCl3/U on liquid Bi electrode at the temperature range of 723–873 K. The impedance data were well fitted with the equivalent circuit. The relationship between j0 and the temperature was determined to model the electrowinning by using liquid Bi electrode. In addition, the electrochemical separation in low concentration uranium from multi-component lanthanide chlorides was demonstrated on liquid Bi electrode. Three electrochemical techniques, including coulometric titration, galvanostatic electrolysis and potentiostatic electrolysis, were applied for the separation of uranium. In which, the coulometric titration showed good separation results. The separation of uranium from lanthanides in terms of mole ratio (U/Ln) was determined, and the different values were discussed in detail. In general, the data from this work can provide theoretical reference for the separation process of various metals by electrochemistry.

Ion-Enhanced Conversion of CO2 to Formate on Porous Dendrite Bismuth Electrodes with High Efficiency and Durability

Facile synthesis of efficient electrocatalysts that can selectively convert CO2 into value-added chemicals remains a challenge. This study presents the electrochemical synthesis of porous Bi dendrite electrodes and details on their activity toward CO2 conversion to formate in aqueous bicarbonate solutions. The as-synthesized multi-layered porous dendrite Bi electrodes exhibit the faradaic efficiency (FE) of ~100% of formate production. The added halides and cations significantly influence the steady-state partial current density for formate production (J FM) (Cl- > Br- ~ I-; Cs+ > K+ > Li+). Density functional theory calculations have revealed that the reaction pathway involving the species *OCOH occurs predominantly, while co-existence of Cs+ and Cl- changes the overall reactions more spontaneously. A photovoltaic cell-assisted electrocatalysis produces formate with FEs of ~95% (J FM ~10 mA cm-2) at an overall solar conversion efficiency of ~8.5%. The Bi electrodes maintain their activity over 360 h without a change in the surface states. Figure 1

A Sensitive Carbon Paste Electrode for Selective Detection of Lead Based on the Synergistic Effect of Bismuth and Chelating Agent

A new type of carbon paste electrode (CPE) has been prepared by mixing bismuth oxide, diphenyl thiocarbazone and graphite powder (Bi-Di-CPE). Trace amount of Pb2+ has been detected via the differential pulse stripping voltammetry (DPV) method with Bi-Di-CPE, which exhibits an extremely high sensitivity about lead. The peak current of Bi-Di-CPE has a linear relationship with the concentration of lead in the range of 5–80 μg l−1, and the limit of detection is as low as 0.15 μg l−1, which meets the detection requirements of heavy metals in tap water (Pb ≤ 10 μg l−1) or in river water (Pb ≤ 50 μg l−1). The diphenyl thiocarbazone acts as a chelating agent which can selectively enriching lead. The bismuth oxide can provide bismuth film and further enriches the lead as a bismuth electrode in the electrodeposition process. The synergistic effect of the chelating agent and bismuth film of the Bi-Di-CPE brings high sensitivity and selectivity to detect heavy metals. Different kinds of modified CPE sensors towards different heavy metals with low cost and high performance may be achieved conveniently by using bismuth particles and corresponding chelating agents.

Formation of double shell during implosion of plasma metal puff Z-pinches

This work presents the results of experimental and theoretical research of impact of tailored density profile and application of external axial magnetic field on initial spatial distribution of the plasma density in the plasma metal puff Z-pinch and on its implosion dynamics. It has been discovered that upon implosion of the plasma metal puff Z-pinch some stripes interpreted as the system of two coaxial shells appear on the optical images. With the help of numerical simulation, the formation of the plasma liner consisting of a mixture of carbon and bismuth ions and formed by the expansion of the plasma jet of the arc burning on the bismuth electrode has been considered in this work. It has been shown that the lightweight carbon ions facilitate formation of the density distribution smoothly decreasing with the increase in radius, that, in turn, leads to suppression of the Rayleigh–Taylor instability in the current sheath upon further implosion. It has also been demonstrated that availability of the two types of ions in plasma considerably different in mass leads to formation (in the compression phase) of a double shell with externally located heavy ions. It has also been revealed that the application of the external axial magnetic field leads to reduction in the plasma metal puff Z-pinch initial diameter.

Enhanced sensitivity and separation for simultaneous determination of tin and lead using paper-based sensors combined with a portable potentiostat

Due to similar properties in the electroanalysis of tin (Sn(II)) and lead (Pb(II)), the voltammograms of tin and lead overlap and it is difficult to simultaneously determine these two metals. Herein, we develop a simple fabricated sensor based on a bismuth nanoparticle-modified screen-printed graphene electrode (BiNP/SPGE) on a paper-based analytical device (PAD) for the simultaneous determination of Sn(II) and Pb(II) and combine it with a portable potentiostat. To overcome crossing interference, the use of hexadecyltrimethylammonium bromide (CTAB) can provide improved separation and enhanced sensitivity for Sn(II) and Pb(II) detection in oxalic acid as a supporting electrolyte while using square-wave anodic stripping voltammetry. Under optimal conditions, the linear range of both metals was determined to be 10–250 ng mL−1, and the calculated limit of detection (3SD/slope) was 0.26 ng mL−1 and 0.44 ng mL−1 for Sn(II) and Pb(II), respectively. This sensor was also applied to simultaneously determine Sn(II) and Pb(II) in canned food samples. The results obtained from the portable potentiostat were similar to the results obtained by a standard method. Therefore, the proposed device can be further improved for the realization of a rapid on-site detector for Sn(II) and Pb(II) detection in real samples.

Front Cover: Ion‐Enhanced Conversion of CO2 into Formate on Porous Dendritic Bismuth Electrodes with High Efficiency and Durability (ChemSusChem 4/2020)

Front Cover: Ion‐Enhanced Conversion of CO₂ into Formate on Porous Dendritic Bismuth Electrodes with High Efficiency and Durability (ChemSusChem 4/2020)

Ion-Enhanced Conversion of CO2 into Formate on Porous Dendritic Bismuth Electrodes with High Efficiency and Durability.

Invited for this month's cover is the group of Prof. Hyunwoong Park at the Kyungpook National University. The image shows the high-efficiency CO2 conversion to formate using multilayered porous dendrite Bi electrocatalysts. The Full Paper itself is available at 10.1002/cssc.201902581.

Selective removal of chloride ions by bismuth electrode in capacitive deionization

Common methods in capacitive deionization (CDI) for selective removal are derived from membrane separation mechanism or size-based intercalation mechanism. In this study, based on the electrochemical activity of bismuth (Bi) material to chloride ions (Cl−) and inertness to sulfate ions (SO42−), Bi electrode is used as anode in CDI to selectively remove Cl− ions from mixed NaCl and Na2SO4 solution. Through the reaction with Bi, Cl− ions are stored in bismuth oxychloride (BiOCl). Results show that Bi electrode exhibits selectivity for Cl− over SO42− with a selectivity coefficient of more than 1.5 in solutions with mole ratio of Cl− to SO42− larger than 1. The selectivity coefficient is greatly dependent on the mole ratio of Cl− to SO42− and increases when the ratio rises. In solution with a fixed Cl−/SO42− mole ratio, higher applied voltage and prolonged time result in higher Cl− ion removal capacity, but not necessarily better selectivity. The highest selectivity coefficient of 4.5 is achieved in 8.5 mM NaCl and 1.1 mM Na2SO4 mixed solution at voltage of 1.6 and 2.0 V after charging for 1 h. These results demonstrate that Bi electrode can selectively remove Cl− ions from mixed solution with a relatively lower concentration of SO42− ions, which provides new insights into ion separation and selective removal by CDI.

Thermodynamics and Kinetics Properties of Lanthanides (La, Ce, Pr, Nd) on Liquid Bismuth Electrode in LiCl-KCl Molten Salt

Electrochemical behaviors of lanthanide (i.e. La, Ce, Pr and Nd) chlorides in LiCl-KCl melt were demonstrated via cyclic voltammetry (CV) and open circuit potential (OCP) techniques at temperatures from 723 K to 873 K. An electrochemical galvanostatic intermittent titration technique (GITT) was performed to obtain the thermodynamic data of lanthanide (Ln) on liquid bismuth electrode. The relationship between activity coefficient and temperature were determined. Galvanostatic pulse (GP) and electrochemical impedance spectroscopy (EIS) as the transient measurements were performed to investigate the interfacial processes of Ln(III) on liquid Bi electrode. The exchange current densities j0 of Ln(III)/Ln were determined by fitting and equivalent circuits, that showed the linear relationship with temperature. In addition, the electrodepositions of La and Ce on liquid Bi electrodes were discussed on the formation of alloys. The products of phase composition and microstructure were conducted by XRD and SEM-EDS, respectively.

Anodic Stripping Voltammetry of Tl(I) Determination with the Use of a Solid Bismuth Microelectrode

For the first time a solid bismuth microelectrode was utilized for anodic stripping voltammetry in the course of Tl(I) ions determination. The proposed solid bismuth microelectrode (ϕ 25 μm) is more environmentally friendly sensor in comparison to bismuth film electrodes as bismuth ions are not added to the supporting electrolyte for bismuth film formation. Furthermore, an amount of metallic bismuth needed for fabrication of proposed sensor is significantly minimized as compared to solid bismuth electrode with a large surface area. Furthermore, the measurements may be carried out from unstirred solutions that gives possibility of performing fields analysis. The optimization of the analytical parameters of Tl(I) determination procedure was presented. A calibration graph for Tl(I) determination was linear in the range from 2 × 10−9 to 2 × 10−7 mol l−1 (deposition time of 120 s). The detection limit for thallium ions determination was 8.3 × 10−10 mol l−1 for deposition time of 120 s. Repeatability of the proposed procedure calculated as RSD% for Tl(I) at concentration of 2 × 10−8 mol l−1 was 5.2% (n = 5). The accuracy of the proposed procedure was successfully checked by analysis of a lake water certified reference material TM 25.5.

Efficient Dechlorination of α-Halocarbonyl and α-Haloallyl Pollutants by Electroreduction on Bismuth.

The electrocatalytic activity of bismuth considered as a low-cost and green electrode material was studied in reductive dechlorination processes. Cyclic voltammetry analyses showed that the Bi electrode exhibited a high catalytic activity to reduce alachlor, a chlorinated herbicide, in the aqueous medium at different pH values. Bulk electrolyses were performed at different potentials and pH values. Alachlor was reduced in deschloroalachlor, its dechlorinated derivative, with a high selectivity (96%) and a current efficiency of 48%. The reductive dechlorination of other chlorinated compounds with an activated carbon atom was then studied, showing that the bismuth electrode catalyzed the electroreduction of chloroacetamides, α-halocarbonyl, and α-haloallyl pollutants. Cyclic voltammetry experiments allowed us to propose a mechanism explaining the high catalytic activity of bismuth to reduce these families of compounds.

Ion‐Enhanced Conversion of CO2 into Formate on Porous Dendritic Bismuth Electrodes with High Efficiency and Durability

Facile synthesis of efficient electrocatalysts that can selectively convert CO2 to value-added chemicals remains a challenge. Herein, the electrochemical synthesis of porous Bi dendrite electrodes and details of their activity toward CO2 conversion to formate in aqueous solutions of bicarbonate are presented. The as-synthesized multilayered, porous, dendritic Bi electrodes exhibit a faradaic efficiency (FE) of approximately 100 % for formate production. Added halides and cations significantly influence the steady-state partial current density for formate production JFM (Cl- >Br- ≈I- ; Cs+ >K+ >Li+ ). DFT calculations revealed that the reaction pathway involving the species *OCOH occurs predominantly and the presence of both Cs+ and Cl- makes the overall reaction more spontaneous. Photovoltaic-cell-assisted electrocatalysis produced formate with an FE of approximately 95 % (JFM ≈10 mA cm-2 ) at an overall solar conversion efficiency of approximately 8.5 %. The Bi electrodes maintain their activity for 360 h without a change in the surface states.

Square-wave adsorptive stripping voltammetric approaches at two in situ modified electrodes as first analytical methods for the quantitative determination of a new anticancer drug candidate

The two adsorptive stripping voltammetric approaches for detection and quantitative determination of diethyl (2E)-2-{(2E)-[1-(4-methylphenyl)imidazolidin-2-ylidene]hydrazinylidene}butanedioate (DIB)—a novel molecule of medical importance—using two sensitive sensors based on modified glassy carbon electrodes as reusable sensors, were developed for the first time. The proposed electrochemical methods are based on adsorptive/reductive behaviour of DIB at two modified carbonic electrodes: a bismuth film-modified glassy carbon electrode (BiF/GCE) and a lead film-modified glassy carbon electrode (PbF/GCE). The electron gain mechanism for the electrochemical reduction of DIB on both developed sensors was proposed for the first time. To achieve the highest sensitivity in adsorptive stripping determinations, various experimental variables (e.g. the composition and pH of the supporting electrolytes, deposition conditions of bismuth and lead films, concentrations of plating solutions, accumulation times and potentials of DIB, etc.) were extensively examined. The comparison of validation parameters obtained during the determination of DIB at two sensors was presented. The excellent linear correlation was found between the monitored adsorptive stripping voltammetric peak current and the DIB concentration in the range of 15–600 μg L−1 at an accumulation time of 30 s (with LOD = 4.2 μg L−1 and LOQ = 14.0 μg L−1) using the BiF/GCE as a sensor. Furthermore, the excellent linear relationship was confirmed between the monitored adsorptive stripping voltammetric peak current and the DIB concentration in the range of 9–900 μg L−1 at an accumulation time of 10 s (with better LOD = 1.5 μg L−1 and LOQ = 5.0 μg L−1), employing the PbF/GCE as a sensor. The two optimized adsorptive stripping voltammetric approaches—as facile, sensitive, reliable and inexpensive—were successfully used as first methods for the quantitative analysis of a novel anticancer agent (DIB) in its pure pharmaceutically acceptable form. However, the practical applicability of square-wave adsorptive stripping voltammetric determination of the electroactive DIB molecule at a PbF/GCE, as the modified electrode of higher sensitivity, was presented after its successful solid phase extraction from a real serum sample.

Adsorption of anions on bismuth and cadmium single crystal plane electrodes from various solvents and ionic liquid mixtures

Electrical double layer characteristics and specific adsorption of anions at Bi and Cd single crystal planes from aprotic and other non-aqueous electrolytes, as well as mixtures of surface-inactive and surface-active ionic liquids have been studied and analysed. Strong influence of sp-metal electronic characteristics (concentration of charge carriers, effective mass of electrons) on the potential of zero charge and differential capacitance values have been demonstrated. Influence of solvent chemical composition and dielectric characteristics on the surface activity and Gibbs adsorption energy values of anions at sp-metal single crystal planes has been demonstrated. Influence of ionic liquid anion composition on the specific adsorption characteristic time constant at Bi(hkl) and Cd(0001) single crystal electrodes in comparison with aprotic and non-aqueous solvent based electrolytes demonstrates the role of the solvent properties on the adsorption process characteristics. The non-aqueous solvent (acetonitrile, ethylene carbonate, propylene carbonate and gamma-butyrolactone) based electrolytes, ionic liquids and ionic liquid mixtures discussed are important electrolytes applicable in electrical double layer capacitors, secondary-ion batteries and other electrochemical devices. Appreciable increase of specific energy and power densities has been demonstrated for supercapacitors with ionic liquid electrolytes containing iodide and bromide anions, development of which was based on the adsorption data collected and discussed.

Influence of Water on the Interface between Hydrophilic Ionic Liquid and Single Crystal Bismuth Electrodes

Ionic liquids (ILs) as solvent-free electrolytes are new favorites for interfacial chemistry as well as for many other potential applications in electrochemical systems, such as supercapacitors, solar cells, fuel cells and secondary ion batteries. One of the main advantages of ILs is the good electrochemical stability. Differently from the hygroscopic, bulky ILs, many ILs are completely miscible with water, conventionally defined as hydrophilic. As an inevitable impurity, water has a strong effect on the surface of ILs within the electrochemical stability region where condensation of water molecules is dependent on applied potential [1-2]. The electrochemical faradic processes at the interface affect both charge transfer and energy storage processes. Those prompt us to focus on the interaction of ILs and water at electrified electrode interface, and the formation kinetics of the electrical double layer (EDL). Adsorption of particles, such as molecules or ions, contributes to the variety of EDL structure at ionic liquid│electrode interface. Halide ions, namely chloride, bromide and iodide, have been studied as part of a group of strongly adsorbing anions to form a dense layer at Bi(hkl) electrodes [3-4]. Electrosorption of water on electrode surface depends not only on the water-ion interaction, but also on the water-eletrode interaction [2]. To further explore the interaction mechanism of water molecules at electrified electrode interface, classical electrochemical methods (cyclic voltammetry and electrochemical impedance spectroscopy) as well as in situ scanning tunneling microscopy (STM) method have been applied to study the effect of water on the interfacial structure of ionic liquid 1-ethyl-3-methylimidazolium trifluoromethylsulfonate (EMImOTf)│Bi(hkl) interface. Single crystal bismuth electrodes as working electrodes have variable electronic properties and surface structure. Electrical equivalent circuit analysis derived from impedance data has been applied to characterize the interfacial processes [3]. The fitted data double layer capacitance (Cdl ) has a good agreement with the series capacitance (Cs ) at lower frequency, suggesting relative sluggishness of dried IL system. Compared with dry EMImOTf, systems with up to 0.1wt% water additive have a pronounced peak in Cdl vs. potential curves, observed within less negative potential region, showing that water has a much stronger interaction with IL anions than with the cations. OTf⁻ anions combined with aliphatic imidazolium cations are generally thought specifically adsorb at metallic electrodes due to the presence of sulfonyl groups. The different metallic properties of bismuth single crystal planes also show a difference in capacitive behavior. Other parameter, such as charge transfer resistance (Rct ) reveals how water adsorption process varies with applied electrode potential. The in situ STM results show that there are no surface reconstruction processes at Bi(111) surface within the studied polarization range. It should be noted, however, that for other single crystal planes surface reconstruction process are observed by varying the applied potential value, being affected by both anion adsorption and water content. Acknowledgements This work was supported by the Estonian Ministry of Education and Research (projects no. IUT 20-13, PUT1033, PUT1107 and PSG 249) and Estonian Centres of Excellence project TK141.