Bi Nanoparticles Research Articles

Electrolyte modulation of BiPS4 concurrently suppressing the Bi coarsening and polysulfide shuttle effect in K-ion batteries

Emerging electrode materials for next generation batteries are consciously designed to contain multi-component active materials that can function synergistically to perform several electrochemical and structural tasks for much improved battery performance. Herein, bismuth phosphorus tetrachalcogenide (BiPS4) is introduced as an excellent anode for potassium-ion batteries. It exhibits a tunnel structure to provide exceptional ion/electron pathways and mechanical integrity against severe volume variations. Abnormal growth and aggregation of Bi nanoparticles and shuttling of the intermediate soluble potassium polysulfides are detected for the first time during the potassiation/depotassiation processes. Rational construction of BiPS4-carbon nanotube hybrid with robust chemical bonds, along with electrolyte modification during the electrochemical tests successfully hinder these two detrimental phenomena. This is revealed by various characterization techniques and theoretical calculations. Consequently, the hybrid delivers a high initial discharge capacity (863 mAh g−1 at 0.05 A g−1) and Coulombic efficiency (81.9%), excellent cycling stability (554 mAh g−1 after 300 cycles at 0.2 A g−1 and 489 mAh g−1 after 600 cycles at 1 A g−1), and superb rate capability (498 mAh g−1 at 2 A g−1) through multiplex reversible conversion and alloying reactions.

Enhancing the optical absorption, conductivity, and nonlinear parameters of PVOH films by Bi-doping

New polymeric nanocomposite films of PVOH (polyvinyl alcohol) embedded with Bi-nanoparticles have been described by scanning electron microscopy and x-ray diffractometer. From UV-visible spectroscopy, the absorption edge shifts to the higher wavelengths direction (redshift). Tauc’s model for optical bandgap transitions demonstrates that the direct and indirect values are reduced with the increase of Bi percentage in the PVOH matrix. In contrast, Urbach energy (tail bandwidth), extinction coefficient, refractive index, and optical conductivity are increased. These indicate the rise of the charge transfer among the Bi nanoparticles and the macromolecules of the matrix. Using Wemple–Di Domenico model for single-oscillator, we calculated the nonlinear optical refractive index and susceptibility. The optical limiting characteristic has been tested via a green laser source of wavelength 533 nm. The present results offer new materials for optical Cut-Off and nonlinear optical applications.

BiVO4 Microplates with Oxygen Vacancies Decorated with Metallic Cu and Bi Nanoparticles for CO2 Photoreduction

BiVO4-based composites are of great interest as photocatalysts for water oxidation, CO2 reduction, and organic pollutant degradation, but their low charge separation efficiency and poor photocataly...

Stabilizer-free bismuth nanoparticles for selective polyol electrooxidation

SummaryBismuth is the least toxic element among heavy metals, an outstanding advantage for environmental and health considerations. Yet, utilizing bismuth as anodic electrocatalyst is hindered by the formation of a spreading Bi(OH)3 inhibitor layer during the anodic process. Herein, we report that bismuth nanoparticles, produced using laser ablation, can avoid such drawbacks. The production of Bi(V) species assists polyol electrooxidation. For glucose, instead of the commonly reported gluconic acid as the product, the Bi(V) species enables highly selective oxidation and C–C bond cleavage to produce arabinonic acid, erythronic acid, and eventually glyceric acid. We not only generate high-valent Bi(V) species for catalytic applications, especially for bioelectrocatalysis where the less toxic bismuth is highly appreciated, but also present Bi nanoparticle as a highly selective electrocatalyst that can break C–C bond. We believe that Bi electrocatalyst can find broader applications in electrochemical biomass conversion and electrosynthesis.

Modulating depth of 1,2-propanediol oxidation over La(III) doped MCM-41 supported binary Pd and Bi nanoparticles for selective production of C3 carbonyl compounds

Selective oxidation of bio-based 1,2-propanediol (PDO) to value-added C3 carbonyl compounds has been received great attention. An alternative mesoporous lanthanum doped MCM-41 (LaM) supported bimetallic PdxBiynanoparticles has been constructed for the selective PDO oxidation. The La doping endows thecatalysts with new basic sites, and synergy between Pd and Bi species enhances the catalytic oxidation capacity. Pure MCM-41 supported PdxBiy/M favors catalyzing the deep oxidation of PDO topyruvic acid, whereas La doped PdxBiy/LaM facilitates theoxidative dehydrogenation of PDO to hydroxyacetone in weak basic aqueous solution (pH < 10). Raising the pH value to 13 efficiently promotes thePDOoxidation to lactic acid over PdxBiy/LaM. Kinetics study and DFT calculation suggeststrong interaction between La species and PDO molecule contributes to the enhanced oxidative dehydrogenation of PDO for PdxBiy/LaM. This work highlights a flexible strategy to produce value-added C3 carbonyl compounds via selective PDO oxidation.

Boosting CO2 Capture and Its Photochemical Conversion on Bismuth Surface

The activity and efficiency of photocatalytic CO2 conversion are limited by a narrow spectral response range and fast electron–hole pair recombination. As plasmonic photocatalysts have become novel catalytic materials for visible light, herein, a typical Bi2O3 photocatalyst as a template to achieve simultaneous in situ bismuth reduction and coupling on the material surface via hydrogen–argon plasma alteration is used. Combining the surface plasmon resonance effect of Bi nanoparticles and the characteristics of composite photocatalytic materials, Bi–Bi2O3 exhibits excellent efficiency in light absorption and separation of photogenerated carriers; photocatalytic activity is significantly enhanced. The CO yields are changed with plasma‐treated duration; the maximum is reached at a treatment time of 3 min, where the rate of CO production is 29.87 μmol h−1 g−1 and CH4 production rate increases from 0 to 6.29 μmol h−1 g−1. The reaction mechanism is further confirmed by in situ Fourier‐transform infrared spectroscopy. Both the efficient light‐generated carrier separation and intense light absorption contribute to the high activity of the well‐designed Bi–Bi2O3 catalyst.

Bi Nanoparticles Embedded in 2D Carbon Nanosheets as an Interfacial Layer for Advanced Sodium Metal Anodes.

Sodium metal is regarded as one of the most prospective next-generation anodes material owing to its high theoretical capacity, low redox potential, low cost, and natural abundance. Its most notable problem is the dendrite growth during Na plating/striping, which causes not only the safety concern but also the generation of inactive Na. Here, it is demonstrated that 2D carbon nanosheets embedded by bismuth nanoparticles (NPs) (denoted as Bi⊂CNs) serve as a robust nucleation buffer layer to endow the sodium metal anodes (SMAs) with high Coulombic efficiencies (CEs) and dendrite-free deposition during long-term cycling. The embedded Bi nanoparticles significantly reduce the nucleation barrier through the "sodiophilic" Na-Bi alloy. Meanwhile, the carbon frameworks effectively circumvent the gradual failure of those Na-Bi nucleation sites. As a result, the metallic Na on the Bi⊂CNs nucleation layer is repeatedly plated/stripped for nearly 7700 h (1287 cycles) at 3mA h cm-2 with an average CE of 99.92%. Moreover, the Na||Na symmetric cells with the Bi⊂CNs buffer layer are stably plated/stripped for 4000 h at 1mA cm-2 and 1mA h cm-2 . It is found that the cycling stability is closely related to the Na utilization of SMAs and current rate.

Cell membrane camouflaged bismuth nanoparticles for targeted photothermal therapy of homotypic tumors

Bi nanoparticles (NPs) have been demonstrated as effective all-in-one type theranostic agent for imaging-guided photothermal therapy, but their applications have been limited by relatively low biocompatibility and target accumulation capacity. To address this issue, we report the camouflage of Bi NPs (size: ~42 ± 2 nm) by using the mouse colon cancer CT26 cells membrane (CT26 CCM). The camouflaging process confers the efficient coating of CCM shell layer with thickness of ~8 ± 2 nm on Bi NPs cores, which can be confirmed by TEM image, zeta potential and protein gel electrophoresis tests. Simultaneously, CCM shell has no side effects on the photoabsorption/photothermal effect. Importantly, Bi@CCM NPs retain significant features of CCM, including good biocompatibility and homologous targeting ability. When Bi@CCM dispersion was intravenously (i.v.) injected into mice, they exhibited higher blood circulation half-life (11.5 h, ~2.9 times) and accumulation amount (4.7 ± 0.56% ID/g, ~2.3 times) in homotypic CT26 tumor compared to those (4.0 h in blood and 2.03 ± 0.60% ID/g in tumor) from uncoated Bi NPs. After 808 nm laser irradiation, CT26 cancer cells could be effectively ablated after the photothermal therapy of high-accumulated Bi@CCM NPs, and then the tumor tends to be eradicated after 12 days. Thus, Bi NPs camouflaged with CT26 CCM have great potential for the targeted photothermal therapy of homotypic tumors.

Improving cycling stability of Bi-encapsulated carbon fibers for lithium/sodium-ion batteries by Fe2O3 pinning

Bi draws increasing attention as anode materials for lithium-ion batteries and sodium-ion batteries due to its unique layered crystal structure, which is in favor of achieving fast ionic diffusion kinetics during cycling. However, the dramatic volume expansion upon lithiation/sodiation and an insufficient theoretical capacity of Bi greatly hinder its practical application. Herein, we report the Fe2O3 nanoparticle-pinning Bi-encapsulated carbon fiber composites through the electrospinning technique. The introduction of Fe2O3 nanoparticles can prevent the growth and aggregation of Bi nanoparticles during synthetic and cycling processes, respectively. Fe2O3 with high specific capacity also contributes to the specific capacity of the composites. Consequently, the as-prepared Bi-Fe2O3/carbon fiber composite exhibits outstanding long-term stability, which delivers reversible capacities 504 and 175 mAh/g after 1000 cycles at 1 A/g for lithium-ion and sodium-ion batteries, respectively.

Origin of anomalous high-rate Na-ion electrochemistry in layered bismuth telluride anodes

Summary van der Waals layered metal chalcogenide Bi2Te3 has shown exceptional capacity and rate capability in alkali-ion batteries but the underlying reaction mechanism with Li+, Na+, and K+ remains undiscovered. It is unexpected that Na+ electrochemistry outperforms Li+ and K+ at high current densities. Here, in situ transmission electron microscopy is used to uncover nanoscale transformations during lithiation, sodiation, and potassiation, which follows two-step conversion and alloying reactions with Li+ and Na+, and three-step intercalation-conversion-alloying reactions with K+. Counterintuitively, sodiation exhibits the highest reaction kinetics, and its origin can be elucidated by first-principles and finite-element simulations in two aspects. The lower interfacial strain accommodation energy between Bi2Te3 and its Na-conversion products allows more facile sodiation phase transformation than Li- and K-ion reactions. The higher electrochemo-mechanical stress concentration at the concave-shaped sodiation reaction front facilitates continued Na-ion diffusion and reaction propagation. These fundamental insights are essential for fast-charging alkali-ion batteries.

Full-spectrum responsive photocatalytic activity via non-noble metal Bi decorated mulberry-like BiVO4

Due to its appropriate bandgap (∼2.4 eV) and efficient light absorption, bismuth vanadate (BiVO4) shows promising photocatalysis activity. However, the charge carrier recombination and poor electron transmission often induce poor photocatalytic performance. Herein, we report a new method to in-situ synthesize non-noble metal Bi decorated mulberry-like BiVO4 by a two-step calcination process. Comprehensive characterizations reveal that non-noble metal Bi nanoparticles grown in-situ on BiVO4 result in the red-shift of the absorbance edge, greatly extending the light absorption from the ultraviolet into the near-infrared region. The surface plasmon resonance excitation of Bi nanoparticles and synergetic effects between Bi and BiVO4 effectively improve the photocatalytic efficiency and promote the separation of photoinduced electron-hole pairs in mulberry-like BiVO4. Density functional theory (DFT) calculation results further verify that the electrons are transferred from Bi to BiVO4 and the formation of OH radical in Bi/BiVO4 is attributed to the lower simulated free energy, which supports our experimental outcomes. This work provides a novel strategy to enhance light absorption and promote efficient solar utilization of photocatalysts for practical applications.

Boosting low-temperature sodium/potassium storage performance of Bi via novel electrochemical milling process

The development of low-temperature (Low-T) sodium/potassium-ion batteries (NIBs/KIBs) with both high power density and high energy density is essential for critical applications (i.e. defense, aerospace). However, it is greatly challenged to realize high-performance electrode material because of the extremely sluggish desolvation of the charge carrier (Na+/K+) at Low-T. Here, we exploit a mechanism implicitly occurring in sodium batteries during cycling to develop it into a top-down method in the synthesis of electrode materials with ultrasmall particle size and pronounced nanoporosity associated with unprecedented electrochemical properties at Low-T. Taking bismuth (Bi) as an example, we demonstrate this novel electrochemical milling process (EMP) to prepare ultrasmall-sized Bi nanoparticles embedded in a three-dimensional (3D) porous carbon framework (EMP-Bi@3DCF) that shows excellent both sodium/potassium storage performance at −20 °C. The ultrasmall sized Bi nanoparticles (~10 nm) via EMP and 3D interconnected porous channels reduce the diffusion path of electron/ion, realizing the ultrafast kinetics process at Low-T. The EMP-Bi@3DCF anodes demonstrate superior rate performances (190 mAh g−1 at 5 A g−1 for NIBs and 233 mAh g−1 at 20 A g−1 for KIBs) and long cycle life (205 mAh g−1 after 2,000 cycles at 10 A g−1 for KIBs) at −20 °C. Furthermore, when used as potassium-ion hybrid capacitors (PIHCs), the EMP-Bi@3DCF exhibits a distinctly better performance than the previously reported PIHCs at Low-T. This work offers a new top-down method to fabricate high-performance electrode materials for both NIBs and KIBs at Low-T.

N-Doped carbon encapsulating Bi nanoparticles derived from metal–organic frameworks for high-performance sodium-ion batteries

Bi@NC was synthesized successfully by using a Bi-MOF as a precursor. Benefitting from the synergistic effect of the Bi nanoparticles and N-doped carbon matrix, a long-term cycling performance was delivered.

A Sodiophilic Carbon Cloth Decorated With Bi-MOF Derived Porous Bi@C Nanosheets for Stable Na Metal Anode

Sodium (Na) metal anode has been considered as the promising candidate for next generation high-energy-density rechargeable batteries such as Na-S, Na-O 2 and Na-CO 2 , owing to its high specific capacity, low electrode potential and low cost. Unfortunately, some intractable problems hinder the practical application, including volume change and dendrite formation induced by inhomogeneous Na nucleation. Herein, 3D carbon cloth (CC) supporting Bi-MOF derived carbon nanosheets containing Bi nanoparticles and carbon shells (CC@Bi@C) were prepared to serve as Na deposition/dissolution hosts, integrating high surface area and favorable sodiophilicity. Due to the existence of Bi sodiophilic sites, Na nucleation and deposition can be induced, rendering uniform and dendrite-free morphology. Moreover, the 3D carbon framework can effectively reduce the current density and uniform distribution of Na + flux, solving the uncontrolled Na dendrite growth. As a result, the CC@Bi@C||Na half cell operating at 1 mA cm -2 for 1 mAh cm -2 exhibits 99.85% Coulombic efficiency for nearly 500 cycles. The symmetric cell maintains stable cycle for more than 300 h at 2 mA cm -2 for 2 mA h cm -2 with low overpotential. This work providers a facile strategy to inhibit dendrite growth and uniform Na deposition.

Influence of the Pd : Bi ratio on Pd-Bi/Al2O3 catalysts: structure, surface and activity in glucose oxidation.

Pd-Bi nanoparticles show high efficiency in catalyzing gluconic acid production by the glucose oxidation reaction. Although this type of catalyst was studied for some time, the correlation between bismuth content and catalytic activity is still unclear. Moreover, there is little information on the principles of the formation of Pd-Bi nanoparticles. In this work, the relation between bismuth content and the activity and selectivity of the PdxBiy/Al2O3 catalyst in the glucose oxidation process was studied. The catalytic samples were prepared by co-impregnation of the alumina support utilizing the metal-organic precursors of Pd and Bi. The samples obtained were tested in the glucose oxidation reaction and were studied by transmission electron microscopy (TEM), X-ray fluorescence analysis, X-ray photoelectron spectroscopy (XPS), and BET adsorption. It has been found that the Pd3 : Bi1 atomic ratio grants the highest catalytic efficiency for the studied samples. To explain this, we predicted stable Pd-Bi nanoparticles using ab initio evolutionary algorithm USPEX. The calculations demonstrate that nanoparticles tend to form Pd(core)-Bi(shell) structures turning to a crown-jewel morphology at lower Bi concentration, thus exposing the active Pd centers while maintaining the promoting effect of Bi.

Carbon Xerogel Nanostructures with Integrated Bi and Fe Components for Hydrogen Peroxide and Heavy Metal Detection.

Multifunctional Bi- and Fe-modified carbon xerogel composites (CXBiFe), with different Fe concentrations, were obtained by a resorcinol–formaldehyde sol–gel method, followed by drying in ambient conditions and pyrolysis treatment. The morphological and structural characterization performed by X-ray diffraction (XRD), Raman spectroscopy, N2 adsorption/desorption porosimetry, scanning electron microscopy (SEM) and scanning/transmission electron microscopy (STEM) analyses, indicates the formation of carbon-based nanocomposites with integrated Bi and Fe oxide nanoparticles. At higher Fe concentrations, Bi-Fe-O interactions lead to the formation of hybrid nanostructures and off-stoichiometric Bi2Fe4O9 mullite-like structures together with an excess of iron oxide nanoparticles. To examine the effect of the Fe content on the electrochemical performance of the CXBiFe composites, the obtained powders were initially dispersed in a chitosan solution and applied on the surface of glassy carbon electrodes. Then, the multifunctional character of the CXBiFe systems is assessed by involving the obtained modified electrodes for the detection of different analytes, such as biomarkers (hydrogen peroxide) and heavy metal ions (i.e., Pb2+). The achieved results indicate a drop in the detection limit for H2O2 as Fe content increases. Even though the current results suggest that the surface modifications of the Bi phase with Fe and O impurities lower Pb2+ detection efficiencies, Pb2+ sensing well below the admitted concentrations for drinkable water is also noticed.

S-scheme bismuth vanadate and carbon nitride integrating with dual-functional bismuth nanoparticles toward co-efficiently removal formaldehyde under full spectrum light

It is crucial to develop more effective photocatalysts in the field of clean environment. In response, the S-scheme BiVO4/g-C3N4 heterojunction modified by in situ reduced non-noble metal Bi nanoparticles was used to synergistically degrade formaldehyde under full spectral irradiation. The results, that investigated by careful characterizations and density functional theory (DFT) calculations, proved that BiVO4/g-C3N4 form an S-scheme heterojunction, which can effectively improve the separation efficiency of photogenic carriers and maintain the original strong redox capability of semiconductor materials. The SPR effect of Bi elemental substance enhanced the optical response and provided more oxidative species. Thus, the photocatalytic activity of BiVO4/Bi/g-C3N4 was significantly improved through their joint efforts, that the degradation efficiency of HCHO (800 ppm) for 6 h is 96.39% under 300 W Xenon lamp without filter with the pseudo-second-order rate constant of 4.16 ppm−1·h−1 and CO2 selectivity of 98.41%. Surprisingly, the degradation efficiency also reached to 49.35% and 32.23% under visible and near-infrared light irradiation, respectively. Moreover, we also tested its photocatalytic decomposition effect on formaldehyde in coatings, indicating that it has a broad prospect in future coatings applications. This study may provide an expected photocatalyst, an efficient non-noble metal modified S-scheme heterojunction, to degrade volatile organic gases under a broad spectrum light.

Bi2O3/Bi nanocomposites confined by N-doped honeycomb-like porous carbon for high-rate and long-life lithium storage

The volume changes of Bi2O3 and Bi, which have a high theoretical gravimetric ca-pacity and high volumetric capacity, during alloying is the main challenge in the fabri-cation of high-performance Bi-based electrodes. In the present study, a simple chemical blowing method is adopted to embed Bi2O3 and Bi nanoparticles generated by thermal decomposition and reduction in an N-doped honeycomb-like porous carbon matrix (Bi2O3/Bi@NHPC). In charge/discharge processes, the honeycomb-like porous carbon matrix effectively prevents the Bi2O3 and Bi nanoparticles from pulverization triggered by volume changes and provides abundant channels for fast electron and Li-ion diffusion. When utilized for lithium storage, the electrode exhibits a high reversible specific capacity of 408 mAh g−1 after 1000 cycles at 1 A g−1. Remarkably, it presents a superior rate capability of 258 mAh g −1 at 10 A g−1 and a decent cycle retention of 78 % at 5 A g−1 after 2000 cycles. The qualitative analysis results reveal that the excellent rate performance and rapid reaction kinetics of the as-prepared electrode are mainly derived from the high capacitive contribution induced by the honeycomb-like porous carbon matrix. The reported results demonstrate that Bi2O3/Bi@NHPC, which has a convenient preparation method, is a potential anode material for lithium-ion batteries.

Nitrogen-doped carbon nanotubes encapsulated Bi nanobuds for lithium based high-performance energy storage devices

Bi-based electrode materials with a high theoretical capacity of 3800 mAh cm−3 and low redox potential of Bi3+/Bi for lithium ion batteries (LIBs) have attracted great attention in energy storage materials. However, the complexity of the synthetic route, structural degradation and instability of the solid electrolyte interphase (SEI) caused by the huge volume change during charge-discharge process restricts its large-scale preparation and practical application, respectively. In this paper, the nitrogen doped carbon nanotubes (N-CNTs) optimal encapsulation Bi nanobuds (Bi@N-CNT) was constructed by a facile solvent grinding method and subsequent annealing reactions that addresses these issues. The one-dimensional encapsulation matrix of N-CNTs in the composites with a high conductivity, not only prevents the exfoliation of Bi nanoparticles and accommodates the volume changes, but also constructs a stable SEI during cycling. This Bi@N-CNT anode with large specific capacity of 452.5 mAh g−1 at 0.2 A g−1 after 100 cycles, unprecedented rate capability and prolonged cyclic life span (209.6 mAh g−1 at 3 A g−1 after 1000 cycles). This work provides a scalable, simple, and efficient evolutionary method for the production of Bi@N-CNT electrode materials, this composite can be used as a potential anode for LIBs, which has a certain enlightening significance for the preparation of other alloy-type anodes.

All roads lead to Rome: An energy-saving integrated electrocatalytic CO2 reduction system for concurrent value-added formate production

Electrochemical CO2 reduction (CO2R) to value-added fuels has been actively pursued to reduce the carbon intensity of our energy and products-driven economy. Conventional CO2R is always coupled with the anodic oxygen evolution reaction (OER), resulting in high electricity input being consumed by the OER due to its large energy barrier and sluggish kinetics. Herein, OER is replaced with selective methanol oxidation reaction (MOR) on non-noble electrocatalysts. In an integrated cell, CO2R is conducted on the cathode of Bi nanoparticles and MOR is performed on the anode of Ni(OH)2 in alkaline electrolyte. Over 92% selectivity for cathodic reduction of CO2 into formate and 100% selectivity for anodic oxidation of methanol to formate are achieved at high current densities within a wide potential range. The use of the integrated system significantly lowers the specific energy consumption by 57.3% reduction for individual CO2R and 71.2% reduction for individual MOR for 1 mol formate generation. This novel strategy for concurrent formate generation at the cathode and anode dramatically increases the valuable fuels production with low electricity consumption. This study thus highlights the promise that coupling CO2R with viable alternative oxidation reaction is theoretically and technically feasible and presents significant economic benefits.