Bi Electrodeposition Research Articles

Characterization of Bismuth Composited to Carbon Nanotube-Coated Titanium Cathode in Electro-Fenton System

Bismuth (Bi) is a highly reactive catalyst for the generation of hydroxyl (∙OH) radicals. Cathodes constructed from composites of Bi and carbon nanotube (CNT) exhibit high stability and low resistance, which enhance their electron transfer capability. In this work, a titanium substrate was coated with multi-walled carbon nanotube (MWCNT/Ti) using electrophoretic deposition process, followed by electrodeposition of Bi onto the MWCNT-coated Ti (Bi/MWCNT/Ti). The effects of Bi electrodeposition time on the surface morphology of Bi/MWCNT/Ti cathodes were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy, and the electrochemical characteristics of each cathode were identified via a series of electrochemical analyses further. The results demonstrated that electrodeposition at −0.85 V vs. Ag/AgCl for 5 min revealed uniform distribution of dense Bi across the surface of cathode, which provides better hydrophilicity for cathode and promotes highest electron transfer rates, respectively; when the Bi/MWCNT/Ti cathode was used as an electro-Fenton (EF) cathode, the EF system achieved a rhodamine B degradation rate of 80.8% after 30 min, which is a significant increase (83.63%) than the unmodified Ti cathode. The use of Bi in EF cathodes improves the efficiency of the EF process.

(Digital Presentation) The Influence of Post-Processing on Dynamic Hydrogen Bubble Templated Bi Modified Graphite Felt in Vanadium Redox Flow Batteries

Graphite felts (GFs) are a widely used electrode material in vanadium redox flow batteries (VRFB) by virtue of their high porosity, chemical stability, low cost and good electrical conductivity. However, the hydrophobicity and the low electrochemical activity are the main obstacles for the use of pristine GF in VFRB applications. To tackle such problems, bismuth has been reported to be a promising catalyst for V2+/ V3+ redox reactions [1]. Post-processing parameters, such as air/vacuum drying, exposure time to water during rinsing step, etc. can impact the performance of the Bi modified GFs, which will correspondingly affect morphology, purity and distribution of the catalyst leading to different kinetics. These parameters are rarely studied and reported in the literature.In this work, an effective synthesis method, the so-called dynamic hydrogen bubble template (DHBT) electrodeposition, has been employed for the deposition of high surface area Bi on GFs [2]. This method involves galvanostatic deposition of the metal at high current densities which is accompanied by hydrogen evolution, and the hydrogen bubbles serve as dynamic template for metal deposition. Cyclic Voltammetry (CV) and Electrochemical Impedance Spectroscopy (EIS) were carried out in a half-cell setup. The kinetics of Bi modified GFs could be obtained qualitatively by using Friedl’s method [3], in which the charge transfer resistance and double layer capacitance from impedance measurements are correlated, and quantitatively from the CV fitting routine in Polarographica developed by Tichter et al. [4]. The kinetic trends derived from both methods are consistent, with Polarographica exhibiting specific quantitative values as compared to Friedl’s method.It has been found that the post processing and drying conditions after Bi electrodeposition affect the performance of the GFs significantly. Therefore, the impacting parameters including electrochemically active surface area, Bi distribution, impurity, etc. are further studied by excluding certain parameters under different conditions. By the two previously mentioned methods of obtaining kinetics and the characterization of SEM and XRD, it is demonstrated that long time exposure to water during the rinsing step combined with vacuum drying after synthesis will promote a relatively higher kinetics than the other post-processing treatments on the Bi modified GFs.Full-cell tests with a VRFB test bench have been carried out. According to the polarization curves and charge-discharge curves at 25 mA/cm2 and 50 mA/cm2, the electrodes with Bi show pronounced advantages over pristine GF, namely, lower overpotential, lower charge voltage, higher discharge voltage and higher electrolyte utilization. Long term cycling will be compared and discussed in detail as well.[1] B. Li et al., “Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery,” Nano Lett., vol. 13, no. 3, pp. 1330–1335, Mar. 2013, doi: 10.1021/nl400223v.[2] M. Yang, “Fern-shaped bismuth dendrites electrodeposited at hydrogen evolution potentials,” J. Mater. Chem., vol. 21, no. 9, p. 3119, 2011, doi: 10.1039/c0jm03213a.[3] J. Friedl and U. Stimming, “Determining Electron Transfer Kinetics at Porous Electrodes,” Electrochimica Acta, vol. 227, pp. 235–245, Feb. 2017, doi: 10.1016/j.electacta.2017.01.010.[4] T. Tichter et al., “Real-space simulation of cyclic voltammetry in carbon felt electrodes by combining micro X-ray CT data, digital simulation and convolutive modeling,” Electrochimica Acta, vol. 353, p. 136487, Sep. 2020, doi: 10.1016/j.electacta.2020.136487.

Surface Structure Control and Charge/Discharge Characteristics of Bismuth Anode Materials By Electrodeposition for Magnesium-Ion Batteries

The magnesium ion secondary battery (MIB) has attracted much attention because magnesium (Mg) metal has high theoretical capacity (3,755 mAh/cm3), high electrochemical stability, and high abundance in the earth. However, developing anode and cathode materials with superior capacity for conventional electrolytes has required considerable study. Bismuth (Bi) has high capacity as an anode and also resists oxidation in Mg-containing electrolyte, so is a promising candidate material. However, experimental studies suggest that the available capacity has not yet reached the theoretical limit, and that the cycle life is short. This is due to sluggish diffusion of Mg2+ into the anode material and the slow interfacial charge transfer. We aimed to improve the electrochemical properties by atomizing the internal and surface structure of the Bi anode and enhancing the diffusibility of Mg2+. In this study, we prepared Bi films by an electrodeposition method, in which the structure of the Bi electrodes could be controlled by changing some of the electrodeposition conditions. We also evaluated the electrochemical properties of Bi anode materials deposited with different deposition times and current densities, to elucidate the relationships between the structure of the Bi anode and its capacity and cycle life.We prepared an electrolytic bath by dissolving H2SO4, Na2SO4 and polyethylene glycol in pure water, and subsequently added H2SO4 to the electrolytic bath to control the pH at 1.2. Before electrodeposition, we removed organic species and native oxide from the Cu foil surface with NaOH and HCl. We employed a Cu plate with an exposed foil area of 2 × 2 cm2 and a carbon plate as the cathode and anode, respectively. The Bi electrodeposition was carried out, while changing the deposition time and current density (from 10 to 50 mA/cm2). The film thickness was controlled by the deposition time (from 1.5 to 3.0 μm), and was calculated based on the weight increase under the assumption that the film was uniform. The surface morphology and crystal structure of the Bi films were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. In addition, the characteristics were compared before and after discharge/charge. The cycle characteristics of the Bi anodes were studied in PhMgCl/THF electrolyte. The bipolar half-cells were assembled with Mg plate as the anode and Bi electrode as the cathode. We established representative galvanostatic charge/discharge profiles of the Bi electrodes, at a current density of 50 mA/g within 0–0.6 V, versus Mg2+/Mg. We evaluated the cyclic stability of the Bi electrodes under the same conditions until the 50th cycle. The elemental composition and chemical bonding state of the Bi films after charge/discharge were evaluated by energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS).Figure 1 shows the cycling performance of Bi films with thicknesses of 1.5, 2.0, and 3.0 μm until the 50th cycle. Each film showed a capacity of about 300 mAh/g at the early stage of cycling, which is the maximum capacity. The capacities were about 1.5 times those of the Bi anodes which Niu et al. prepared by powder metallurgy. The cycle performance differed among Bi films differing in thickness, and the 1.5-µm Bi film maintained the maximum capacity until the 25th cycle. Thus, film thickness had an impact on the cycle performance.Figure 2 shows the surface morphology of Bi films with different thicknesses before and after the charge/discharge reaction. The figure also shows the compositional ratio of Bi to Mg on the surface of the Bi films. As the film thickness increased, agglomerates involving a large number of particles, indicated by the circles marked by “A” in Fig. 2, tended to increase in diameter from 1 to 3 µm. After charging/discharging, Mg dendrites were observed on the surface of the Bi films with thicknesses of 2 and 3 µm (circles marked by “B”), which resulted in a low capacity maintenance rate. Thus, the localized formation of Mg dendrites on the Bi surface could explain the decreased cycle performance of the Bi films prepared in this study. Figure 1

Electrochemical Study of Bi2Se3 Single Crystals

Bi2Se3 single crystals have attracted the attention of an extensive research community because of their many attractive properties: as a model topological insulator (TI), a layered structure and a promising platform for surface catalysis studies. However, despite often being studied under ultrahigh vacuum, there are very few studies of either the surface chemistry at ambient pressure or their electrochemistry. We have already demonstrated the protection and in-situ imaging and modification of bismuth chalcogenide single crystals in an electrochemical environment1,2. The present work shows that different choices of chalcogenide (Se in place of Te) and electrolyte yield differences in the oxidative dissolution process. We also investigate how the charge transfer resistance changes during electrochemical oxidation and reduction processes. Oxidative dissolution significantly increases the Bi2Se3 charge transfer resistance, measured by electrochemical impedance spectroscopy (EIS) using the ferrocyanide/ferricyanide redox couple. The charge transfer resistance only partially recovers during subsequent electrochemical reduction. As a further step in the electrochemical modification of bismuth chalcogenides, we studied metal electrodeposition. For example, we imaged Bi electrodeposition on a bismuth selenide single crystal in-situ for the first time, showing that it gives rise to characteristic triangular structures with kink-free step edges, the motion of which can be followed during island growth. The deposition is also highly reversible.

Early-Stage Growth Mechanism and Synthesis Conditions-Dependent Morphology of Nanocrystalline Bi Films Electrodeposited from Perchlorate Electrolyte.

Bi nanocrystalline films were formed from perchlorate electrolyte (PE) on Cu substrate via electrochemical deposition with different duration and current densities. The microstructural, morphological properties, and elemental composition were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and energy-dispersive X-ray microanalysis (EDX). The optimal range of current densities for Bi electrodeposition in PE using polarization measurements was demonstrated. For the first time, it was shown and explained why, with a deposition duration of 1 s, co-deposition of Pb and Bi occurs. The correlation between synthesis conditions and chemical composition and microstructure for Bi films was discussed. The analysis of the microstructure evolution revealed the changing mechanism of the films’ growth from pillar-like (for Pb-rich phase) to layered granular form (for Bi) with deposition duration rising. This abnormal behavior is explained by the appearance of a strong Bi growth texture and coalescence effects. The investigations of porosity showed that Bi films have a closely-packed microstructure. The main stages and the growth mechanism of Bi films in the galvanostatic regime in PE with a deposition duration of 1–30 s are proposed.

Bi electrodeposition on WO3 photoanode to improve the photoactivity of the WO3/BiVO4 heterostructure to water splitting

In view of the urgency to replace fossil fuel-based energy sources with sustainable and renewable sources, much has been done to discover new materials and/or production methods that can provide devices capable of converting solar energy into chemical or electrical energy. This work describes the electrodeposition of Bi on WO3 film and its subsequent conversion to BiVO4 with the addition of NH4VO3 and heat treatment. In this way, a WO3/BiVO4 heterojunction is obtained. With this methodology, it is possible to observe the formation of BiVO4 nanostructures with pillar shapes and a photocurrent increase of 300 times compared to films obtained by drop-casting. At 1.23 V vs RHE (Reversible Hydrogen Electrode), the photocurrent achieved with the photoanode reaches 2.1 ± 0.3 mA cm−2, which is 35 times higher than pure BiVO4 and 23 times higher than pure WO3. Transient absorption spectroscopy studies show an increase in the time constants for the recombination of charge carriers to the WO3/BiVO4 heterojunction. Electrodeposition is a relatively simple, easy to use, and scalable technique. So, it is expected that its use for the production of photoelectrodes will be more widespread.

Functional Bi Coatings as A Perspective Material for Radiation Shields Production against Electron Radiation

Currently, medicine uses a large number of devices and sources of ionizing radiation, which have a dangerous effect on workers in medical diagnostic rooms and patients. Human organs are very sensitive to the damaging effects of radiation. The commonly used material for radiation protection proposes is lead. In recent years, bismuth deposition has become an interesting subject for the electrochemical community because of its unique properties. There are a limited number of authors dealing with Bi films onto metallic substrates by electrochemical deposition. The conditions of Bi electrodeposition and the structure of Bi coatings were examined. The shielding efficiency of Bi coatings under electron irradiation with 1,6–1,8 MeV was measured. The electron beam attenuation coefficient was estimated by the changing of current-voltage characteristics of semiconductor test structures which were located with and without shields. It has been determined that optimal shielding efficiency and mass-dimensional parameters have Bi shields with 2 g/cm 2 mass thickness and 156 shielding efficiency.

Dual Tinting Dynamic Windows Using Reversible Metal Electrodeposition and Prussian Blue.

Electronically tintable windows based on reversible metal electrodeposition are a promising alternative to electrochromic materials due to the high optical contrast imparted by the opacity of thin metal films. While traditional metal-based dynamic windows utilize a metal counter electrode frame, metal electrodeposition on the working electrode must be paired with a plane-parallel counter electrode that facilitates transverse ion migration to enable uniform metal electrodeposition on a large scale. In this manuscript, we develop dynamic windows that combine reversible Bi electrodeposition on the working electrode with a Prussian blue counter electrode that acts as both a charge storage layer that intercalates K+ ions and an anodically coloring material. Since both electrodes darken during window tinting, 25 cm2 devices switch with an optical contrast of ∼67.5% at 700 nm in only 3 s, making them the fastest dynamic windows using reversible metal electrodeposition reported on this scale.

Electrodeposition of Bi Thin Films on n-GaAs(111)B. I. Correlation between the Overpotential and the Nucleation Process

Bismuth thin films constitute a promising nanostructure for the fabrication of spin-based devices. To achieve this goal, it is necessary to obtain high-quality Bi layers with controlled and reproducible properties. Therefore, studies focused on the understanding of the nucleation process and the correlation between the growth conditions and the film properties are of great interest. In this work, we have studied the electrodeposition of Bi thin films onto GaAs(111)B substrates at different overpotentials. In Part I, we have analyzed the nucleation of the films by means of potentiostatic curves. The current density transients have been deconvoluted into individual processes taking into account the energy band diagram of the semiconductor–electrolyte interface. The deconvolution of the current density transients indicates that Bi electrodeposition follows a 3D nucleation controlled by diffusion, accompanied by concurrent processes such as both proton adsorption and reduction. The competition of these proces...

New route of fabricating BiOI and Bi2O3 supported TiO2 nanotube arrays via the electrodeposition of bismuth nanoparticles for photocatalytic degradation of acid orange II

Well dispersed Bi nanostructures were synthesized on TiO2 nanotube arrays (TNAs) via a facile electrochemical deposition route at room temperature, employing Bi(NO3)3·5H2O as the reactant with the assistance of complexing agent and surfactant. The structures of the as-prepared product were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction and energy dispersive spectrometer. The influence of preparation conditions on Bi electrodeposition were investigated systematically. The results showed that the concentration of surfactant, the deposition voltage and pH value could markedly affect the morphology of Bi-TNAs. The prepared Bi-TNAs have been used to fabricate BiOI and Bi2O3 semiconductors supported on TNAs, which exhibited high visible-light photocatalytic efficiency for acid orange II degradation. This study predicates a promising path to synthesizing Bi-based photocatalysts on TNAs.

Study of Multilayer X-ray Absorbers to Improve Detection Efficiency of TES X-ray Microcalorimeter Arrays

We report the fabrication and evaluation of the Cu/Bi bilayer absorber with electrodeposition. We designed the Cu/Bi absorber to satisfy the requirements for scanning transmission electron microscope (STEM). The residual resistivity ratios of films of Cu and Bi with electrodeposition was \({5.91\pm 0.49}\) and \({2.06\pm 0.33}\), respectively; these values are sufficient for the requirements of STEM. We found that the Cu/Bi bilayer absorber TES microcalorimeter experienced a pulse-shape variation and we considered that these variations were caused by the quality of the contact surface between the absorber and TES. In addition, we examined the structure of the absorber using focus ion beam analysis and STEM. The results suggest that an oxidation between the Cu and seed layer, in which the layer is an electrode for electrodeposition, yielded variations. Moreover, thermal simulation suggests that the thermal conduction between the absorber and TES caused variations. The results of this study will improve the process of Bi electrodeposition.

In situ video-STM studies of the mechanisms and dynamics of electrochemical bismuth nanostructure formation on Au.

The microscopic mechanisms of Bi electrodeposition on Au(111) and Au(100) electrodes in the overpotential regime were studied by in situ scanning tunneling microscopy with high spatial and temporal resolution. Atomic resolution images of the needle-like Bi(110) deposits formed on Au(111) reveal the central influence of covalent Bi-Bi bonds on the deposit morphology. In the straight steps along the needle edges the Bi atoms are interlinked by these bonds, whereas at the needle tip and at kinks along the needle edges dangling bonds exist, explaining the rapid structural fluctuations at these sites. For ultrathin Bi deposits on Au(100) a more open atomic arrangement was found within the surface plane, which was tentatively assigned to an epitaxially stabilised Bi(111) film. Furthermore, well-defined nanowires, consisting of zigzag chains of Bi surface atoms, were observed on this surface.

Spatio-temporal organization in alloy electrodeposition: a morphochemical mathematical model and its experimental validation

This paper proposes a novel mathematical model for the formation of spatio-temporal patterns in electrodeposition. At variance with classical modelling approaches that are based on systems of reaction–diffusion equations just for chemical species, this model accounts for the coupling between surface morphology and surface composition as a means of understanding the formation of morphological patterns found in electroplating. The innovative version of the model described in this work contains an original, flexible and physically straightforward electrochemical source term, able to account for charge transfer and mass transport: adsorbate-induced effects on kinetic parameters are naturally incorporated in the adopted formalism. The relevant non-linear dynamics is investigated from both the analytical and numerical points of view. Mathematical modelling work is accompanied by an extensive, critical review of the literature on spatio-temporal pattern formation in alloy electrodeposition: published morphologies have been used as a benchmark for the validation of our model. Moreover, original experimental data are presented—and simulated with our model—on the formation of broken spiral patterns in Ni–P–W–Bi electrodeposition.

Nucleation and Growth of Bismuth Electrodeposition from Alkaline Electrolyte

The early stages of bismuth (Bi) electrodeposition on glass carbon electrode from alkaline electrolyte were studied by cyclic voltammetry, chronoamperometry, scanning electron microscopy, atomic force microscopy and X-ray diffraction. The CV analysis showed that the electrodeposition of Bi was determined to be quasireversible process with diffusion controlled. The current transients for Bi electrodeposition were analyzed according to the Scharifker-Hills model and the Heerman-Tarallo model. It can be concluded that the nucleation and growth mechanism was carried out under a 3D instantaneous nucleation, which was confirmed by SEM analysis. The kinetic growth parameters were obtained through a nonlinear fitting. In addition, the Bi film obtaining at -0.86 V for 1 hour was of compact and uniform surface with good smoothness, small roughness and a very high purity. The Bi film were indexed to rhombohedral crystal structure with preferred orientation of (0 1 2) planes to growth.

Electrodeposition and characterization of manganese–bismuth system from chloride based acidic bath

In this work, Mn–Bi system has been successfully electrodeposited on Cu/Si substrates from aqueous ammonium chloride containing electrolyte. A thermodynamic study of the electrolysis bath highlights the possible formation of manganese complexes ( MnCl + , MnCl 2 , MnC l 3 − ) and bismuth complexes ( BiCl 2+ , BiC l 2 + , BiCl 3 , BiC l 4 − , BiC l 5 2 − , BiC l 6 3 − ) . The mechanism process involving Mn and Bi electrodeposition is investigated by cyclic voltammetry. Mn–Bi films can be grown under potentiostatic control. The physico-chemical, morphological and structural characterizations of the deposits were carried out by scanning electron microscopy (SEM) and X-rays analysis (XRD). The results reveal a granular surface quality and a heterogeneous chemical composition of the films. The energy dispersive spectroscopy (EDS) analysis reveals the presence of manganese and bismuth peaks whose relative intensities vary according to the imposed potential and the position on the sample. The X-rays diffraction analysis showed three different crystalline phases: α-manganese (body centred cubic system), γ-manganese (body centred tetragonal system) and bismuth (rhombohedral system).

Three-dimensional microfabrication process using Bi electrodeposition for a highly sensitive X-ray imaging sensor

A microscale Bi electrodeposition process was developed and applied to the three-dimensional fabrication of a highly sensitive X-ray imaging sensor, so called X-ray microcalorimeter, which has an array of sensing elements with a mushroom-shaped X-ray absorber. The composition and operating conditions for Bi electrodeposition were optimized and flat, smooth Bi deposits were obtained by applying additives such as diethylenetriamine pentaacetic acid (DTPA) and sodium n-dodecyl sulfate (SDS). The results of ultraviolet (UV)–visible absorption spectroscopy and polarization curves from the Bi electrodeposition solution indicated that the formation of a DTPA–Bi(III) complex and an increase of overpotential for Bi electrodeposition in the presence of SDS improved the solution stability as well as the surface morphology of the deposited film. The mold for the mushroom-shaped microstructure array was formed from a single-layered photoresist coating by applying sequential exposure steps for the “stem” part and the “roof” part. The absorber array was successfully fabricated by the Bi electrodeposition into the mold, precise polishing, and mold removal processes.

Kinetics of Monolayer Bi Electrodeposition on Au(111): Surface X-ray Scattering and Current Transients

The kinetics of Bi monolayer electrodeposition (underpotential deposition) on the Au(111) electrode was investigated using surface X-ray scattering and electrochemical methods. The current and X-ray intensity transients were measured simultaneously using a low-resistance drop cell that has a potential response time less than 50 μs. Three independent measurements of the Bi coverage transients were obtained, which are related to (1) the integrated charge, (2) the adsorbed Bi, irrespective of the adsorption site, and (3) the adsorbed Bi with a well-defined (2×2) structure. The zero-coverage ↔ commensurate (2×2)-Bi phase transition occurs on the millisecond time scale, 3 orders of magnitude more rapidly than the (2×2)-Bi ↔ high-coverage incommensurate (p×√3)-2Bi phase transition. Nucleation and growth kinetics was observed for both transitions involving Bi desorption. Langmuir adsorption kinetics was observed for both transitions involving Bi adsorption. Comparison of the total coverage with that measured by in-plane diffraction intensity suggests fast coarsening of islands for the transition for the zero-coverage ↔ commensurate (2×2)-Bi phase transition.