Bismuthene Nanosheets Research Articles

Bismuthene nanosheets as a photodynamic and photothermal antibacterial agent under NIR light illumination

Bacterial infections remain a significant public health burden due to the emergence of antibiotic resistance and their non-specific cytotoxic effects, leading to the search for novel antibacterial agents. Two-dimensional (2D) pnictogens, which stand out with their advantegeous properties such as large surface areas, compatibility with biological systems, and permeability across biological membranes, have emerged as potential materials in the fight against bacterial infections. By considering all these advantages, here for the first time, the antibacterial activity of 2D bismuth (Bismuthene, Biene) on Gram-negative Escherichia coli (E. coli) and Pseudomonas aeruginosa (P. aeruginosa), Gram-positive Staphylococcus aureus (S. aureus) and Methicillin-Resistant Staphylococcus aureus (MRSA) were examined under NIR light illumination. A growth curve analysis was conducted with a concentration of 256 μg*mL−1 of exfoliated Biene nanosheets to assess the inhibition effect and corresponding antibacterial effect (%) against each bacterial strain. The photodynamic theraphy (PDT) and photothermal therapy (PTT)-mediated antibacterial mechanisms were explored by analyzing the generation of reactive oxygen species (ROS) via Glutathione (GSH) oxidation assay while a photothermal camera monitored temperature dynamic changes during irradiation. The high specific surface area-dependent membrane damage ability of Biene and morphological changes of the bacteria were visualized by field emission scanning electron microscope (FESEM). The exciting growth inhibition activity of Biene nanosheets for all bacterial strains was increased during irradiation, and breathtakingly the inhibition rate reached up to ≥ 99.1 % for P. aeruginosa, S. aureus, and MRSA. Besides, S. aureus and MRSA are more susceptible to Biene than E. coli and P. aeruginosa.

Bismuthene - Tetrahedral DNA nanobioconjugate for virus detection

In this work, we present an electrochemical sensor for fast, low-cost, and easy detection of the SARS-CoV-2 spike protein in infected patients. The sensor is based on a selected combination of nanomaterials with a specific purpose. A bioconjugate formed by Few-layer bismuthene nanosheets (FLB) and tetrahedral DNA nanostructures (TDNs) is immobilized on Carbon Screen-Printed Electrodes (CSPE). The TDNs contain on the top vertex an aptamer that specifically binds to the SARS-CoV-2 spike protein, and a thiol group at the three basal vertices to anchor to the FLB. The TDNs are also marked with a redox indicator, Azure A (AA), which allows the direct detection of SARS-CoV-2 spike protein through changes in the current intensity of its electrolysis before and after the biorecognition reaction. The developed sensor can detect SARS-CoV-2 spike protein with a detection limit of 1.74 fg mL−1 directly in nasopharyngeal swab human samples. Therefore, this study offers a new strategy for rapid virus detection since it is versatile enough for different viruses and pathogens.

Electrochemical field emission effect of ordered bismuthene electrode for supercapacitive iontronic skin with high thermal adaptability

In a biomimetic iontronic electrochemical system, the interior ions can move accompanied by surrounding charges, and then facilitating the integral carrier transfer, yet their transfers are still restricted by concentration gradient and temperature. Here, an ordered porous bismuthene electrode is designed, composed by bismuthene, bismuthene-derived Bi2O3&BiOCl, and borophene materials, with supercapacitive 4.96 F g−1 attribute retaining 89.6 % after 29,600 cycles, and the dispersive bismuthene nanosheets are also embedded into regenerated silk fibroin as elastic electrolyte. The resultant symmetrical iontronic pressure sensor shows high sensitivity of 2.31 kPa−1 in a wide 0.2–10 kPa range, and 0.41 kPa−1 sensitivity ranging 10–48 kPa, fast response/recovery time of 60/50 ms, and low detection limit of 0.45 Pa. The simulation and mechanism analysis demonstrate that a field emission effect plays an important role in electrolyte, in which the ions around the ordered bismuthene as emitters are launched and moved along the inner bismuthene nanosheets, step by step, to enormously shorten the ions migration path and effectively accelerate ion-charge pair transfer. Compared to the device without bismuthene in electrolyte, the sensitivity of sensor is improved by 23.81 times with high reproducibility over 1000 cycles. Additionally, the poly (3, 4-ethylenedioxythiophene): poly (styrene sulfonate) in electrolyte effectively constrains the movements of polymer molecules, contributing to high temperature adaptability from −15 to 70 ℃. In practical application, a tiny pressure monitoring in hot/cold perception is demonstrated, revealing a promising application in wearable systems and intelligent robotics.

Preparation of high‐performance bismuthene thermoelectric composites doped with graphene using UV‐curing 3D printing technology

AbstractThermoelectric materials are of tremendous interest due to their capacity to convert waste heat into useful electrical energy. Bismuthene nanosheets (BiNS) have recently emerged as a promising material for thermoelectric applications because of their unique two‐dimensional structure and low thermal conductivity. However, the development of efficient and scalable methods for preparing BiNS‐based thermoelectric composites with improved performance remains a challenge. In this study, we reported a novel approach to preparing a thin film BiNS‐based thermoelectric composite with UV‐curing 3D printing technology. The composite was prepared using BiNS as the filler and a UV‐sensitive resin as the matrix, which contained 5 vol% graphene as the third phase to enhance the thermoelectric performance of the composite. The results showed that the prepared composite exhibited stable thermoelectric performance, with a maximum power factor of 311.79 ± 13.90 μW/mK2 when the volume fraction of BiNS reached 95 vol%. The electrical conductivity of the composite improved significantly as the volume fraction of BiNS increased from 75 to 95 vol%. The Seebeck coefficient remained essentially unchanged in the range of 70.1–70.7 μV/K. These findings demonstrate the potential of BiNS‐based thermoelectric composites prepared by UV‐curing 3D printing technology for practical applications in energy harvesting and cooling devices.Highlights A simple, efficient and scalable method for BiNS thermoelectric composites. UV‐curing 3D printing technology was used for fabrication. The BiNS composite exhibited stable thermoelectric performance. The electrical conductivity of the composite improved significantly. This BiNS composite showed great potential in thermoelectric application.

β-Glycosidase sensitive oral nanoparticles for combined photothermal and chemo treatment of colorectal cancer.

Colorectal cancer is one of the most common malignant tumors in the world, and its treatment strategies mainly include surgical resection, chemotherapy, adjuvant radiotherapy, and immunotherapy. Among them, chemotherapy inevitably produces systemic toxicity due to the lack of tumor targeting properties and drug resistance caused by long-term medication frequently occurs, immensely constraining the efficacy of chemotherapy alone. To solve the above-mentioned problems, rhamnolipid was used to encapsulate the chemotherapeutic drug 5-FU and photothermal agent bismuthene nanosheets (BiNS), chitosan was applied as the shell of the nanoparticle, and BiNS@RHL-CS/5-FU NPs for oral administration was successfully prepared. When transported in the stomach and small intestine, the double protection of rhamnolipid and chitosan shell prevented the early release of BiNS and 5-FU. When transported to the colon, β-glycosidase existing in the microenvironment along with elevated pH degraded the chitosan shell, and the reduction in particle size was beneficial for tumor tissue to uptake nanoparticles, thus greatly improving the tumor targeting ability of 5-FU and reducing the systemic toxicity. Due to the presence of BiNS, 1.0 W cm-2 808 nm laser irradiation significantly increased the temperature of the tumor site, not only killing tumor cells directly but also promoting cell uptake and penetration of nanoparticles in the tumor tissue, accelerating the release of 5-FU and improving the sensitivity of tumor cells to chemotherapy, eventually solving the shortcomings of traditional chemotherapy alone. Excellent anti-tumor efficacy has been achieved in both in vitro and in vivo experiments.

Synergized photothermal therapy and magnetic field induced hyperthermia via bismuthene for lung cancer combinatorial treatment

Thanks to its intrinsic properties, two-dimensional (2D) bismuth (bismuthene) can serve as a multimodal nanotherapeutic agent for lung cancer acting through multiple mechanisms, including photothermal therapy (PTT), magnetic field-induced hyperthermia (MH), immunogenic cell death (ICD), and ferroptosis. To investigate this possibility, we synthesized bismuthene from the exfoliation of 3D layered bismuth, prepared through a facile method that we developed involving surfactant-assisted chemical reduction, with a specific focus on improving its magnetic properties. The bismuthene nanosheets showed high in vitro and in vivo anti-cancer activity after simultaneous light and magnetic field exposure in lung adenocarcinoma cells. Only when light and magnetic field are applied together, we can achieve the highest anti-cancer activity compared to the single treatment groups. We have further shown that ICD-dependent mechanisms were involved during this combinatorial treatment strategy. Beyond ICD, bismuthene-based PTT and MH also resulted in an increase in ferroptosis mechanisms both in vitro and in vivo, in addition to apoptotic pathways. Finally, hemolysis in human whole blood and a wide variety of assays in human peripheral blood mononuclear cells indicated that the bismuthene nanosheets were biocompatible and did not alter immune function. These results showed that bismuthene has the potential to serve as a biocompatible platform that can arm multiple therapeutic approaches against lung cancer.

Bismuthene nanosheets prepared by an environmentally friendly method and their thermoelectric epoxy nanocomposites

Theoretical research has predicted high thermoelectric performance for bismuthene nanosheets, but it is a great challenge to prepare these nanosheets due to low efficiency and intensive oxidation. We herein report an efficient, environmentally friendly preparation method for bismuthene nanosheets, each being 1–1.5 nm thick in average, through mechanochemical treatment with an ethanol system. The system was found to prevent adverse oxidation in comparison with a pure water system. Although neither the oxidation reactions nor the exfoliation could significantly change the Seebeck coefficient of bismuthene nanosheets, their power factor was measured as 155.6 ± 15.4 μW·m-1K-2. An epoxy nanocomposite was prepared containing 99 vol% of bismuthene nanosheets, to create a thermoelectric generator. It converted a temperature gradient of 11°C generated by human body into an electrical output of 18.62 nW. Our mechanochemical exfoliation method for the preparation of low-oxidation bismuth nanosheets offers insights for large-scale fabrication of nanosheets and their composites for industrial applications. It advances the field of thermoelectric nanocomposites.

Vertically Aligned Bismuthene Nanosheets on MXene for High-Performance Capacitive Deionization.

Capacitive deionization has been considered as a promising solution to the challenge of freshwater shortage due to its high efficiency, low environmental footprint, and low energy consumption. However, developing advanced electrode materials to improve capacitive deionization performance remains a challenge. Herein, the hierarchical bismuthene nanosheets (Bi-ene NSs)@MXene heterostructure was successfully prepared by combining the Lewis acidic molten salt etching and the galvanic replacement reaction, which achieves the effective utilization of the molten salt etching byproducts (residual copper). The vertically aligned bismuthene nanosheets array evenly in situ grown on the surface of MXene, which not only facilitate ion and electron transport as well as offer abundant active sites but also provide strong interfacial interaction between bismuthene and MXene. Benefiting from the above advantages, the Bi-ene NSs@MXene heterostructure as a promising capacitive deionization electrode material exhibits high desalination capacity (88.2 mg/g at 1.2 V), fast desalination rate, and good long-term cycling performance. Moreover, the mechanisms involved were elaborated by systematical characterizations and density functional theory calculations. This work provides inspirations for the preparation of MXene-based heterostructures and their application for capacitive deionization.

Covalent Functionalization of Antimonene and Bismuthene Nanosheets.

Antimonene and bismuthene are promising members of the 2D pnictogen family with their tunable band gaps, high electronic conductivity, and ambient stability, making them suitable for electronic and optoelectronic applications. However, semi-metal to semiconductor transition occurs only in the mono/bilayer regime, limiting their applications. Covalent functionalization is a versatile method for tuning materials' chemical, electronic, and optical properties and can be explored for tuning the properties of pnictogens. In this work, emissions in liquid exfoliated antimonene and bismuthene are observed at ≈2.23 and ≈2.33eV, respectively. Covalent functionalization of antimonene and bismuthene with p-nitrobenzene diazonium salt proceeds with the transfer of lone pairs from Sb/Bi to the diazonium salt, introducing organic moieties on the surface attached predominantly via Sb/BiC bonds. Consequently, Sb/Bi signatures in Raman and X-ray photoelectron spectra are blue-shifted, implying lattice distortion and charge transfer. Interestingly, emission can be tailored upon functionalization to 2.18 and 2.27eV for antimonene and bismuthene respectively, and this opens the possibility of tuning the properties of pnictogens and related materials. This is the first report on covalent functionalization of antimonene and bismuthene. It sheds light on the reaction mechanism on pnictogen surfaces and demonstrates tunability of optical property and surface passivation.

Two dimensional layered bismuthene nanosheets with ultra-fast charge transfer kinetics as a superior electrode material for high performance asymmetric supercapacitor

Two dimensional (2D) materials with unique quantum chemistry, tunable interlayer bandgap, and active functional groups extensively enhance the electrochemical behavior in electrochemical energy storage devices. Herein, we synthesize the bismuthene nanosheets from bulk metallic bismuth powder using the standard liquid phase exfoliation technique. As a result, the X-ray diffraction (XRD) spectrum reveals the rhombohedral crystal structure of the bismuthene nanosheets and their active functional groups have been identified by Fourier transform infrared (FTIR) analysis. Likewise, the high resolution transmission electron (HR-TEM) microscopy reveals the morphology and surface nature of the 2D bismuthene nanosheets with high transparency with the interplanar lattice spacing of 0.328 nm. Moreover, the atomic force microscopy (AFM) shows the stacking of 11–12 layer nanosheets with an average sheet thickness of about 4.7 nm. Cyclic Voltammetry (CV) analysis of the delaminated bismuthene nanosheets provides the gravimetric capacity of 350 mAh/g at 10 mV/s. Furthermore, Trasatti and Dunn's approach demonstrates the charge storage process and the obtained total, outer, and inner capacity of bismuthene nanosheets are 724.6, 34.7, and 689.6 mAh/g respectively with the capacitive and diffusive contributions are 95.2% and 4.8% correspondingly. Moreover, the asymmetric supercapacitor (ASC) based on bismuthene and activated carbon (AC) delivers the maximum specific capacity of 87.3 mAh/g at 1 A/g, together with the energy density of 27.23 Wh/kg corresponding to the power density of 312.5 W/kg.

Photocatalytic and photothermal bismuthene nanosheets as drug carrier capable of generating CO to improve drug sensitivity and reduce inflammation for enhanced cancer therapy

Bismuthene nanosheet is a nontoxic and low-cost two-dimensional material, and has been reported with very limited biomedical applications. In this report, for the first time, we reported the utilization of bismuthene nanosheet for combined photothermal, photocatalytic and chemotherapy for cancer treatment. Partially oxidized bismuthene nanosheet was modified with polyethylene glycol (POBNS-PEG) and used as a drug delivery vehicle for the first time (antitumor drug doxorubicin (DOX) was used as a model drug, POBNS-PEG/DOX). POBNS-PEG itself shows a photothermal treatment ability under the near infrared light and this treatment can additionally promote better cellular uptake of POBNS-PEG and DOX. More importantly, POBNS-PEG was found to be able to reduce CO2 in cancer cells to CO through photocatalytic pathways under red light irradiation for the first time. The generated CO could obviously reduce the inflammation caused by photothermal treatment and drug resistance of tumor cells caused by chemotherapy. These three combined functions bring the three-in-one multifunctional bismuthene nanosheets not only have a significant antitumor effect but also reduce the side effects, making it with high clinical potentials.

Passively Q-switched Nd:GYAP laser at 1.3 μm with bismuthene nanosheets as a saturable absorber

Two-dimensional (2D) saturable absorbers (SAs) with air-stable have a promising application in laser pulse generation. Few-layer bismuth (Bi), as a novel 2D material, exhibits unique characteristics, such as high carrier mobility, great long-term stability, moderate bandgap and air stability, which has drawn increasing attention of researchers. In this work, few-layer bismuthene nanosheets were prepared and used for fabricating SA. Based on the synthesized bismuthene nanosheets SA, an all-solid-state passively Q-switched Nd:GYAP laser at 1.3 μm was realized for the first time. The shortest pulse width of 361 ns was obtained under the maximum absorbed pump power of 3.55 W, corresponding to the repetition rate of 365 kHz and the peak power of 1.52 W. Our result reveals that bismuthene nanosheets could be a promising SA for pulse laser generations in the near-infrared region.

Bismuthene with stable Bi[sbnd]O bonds for efficient CO2 electroreduction to formate

Atomic configuration engineering is a promising strategy to realize the efficient and precise CO2 electroreduction towards the targeted products. Herein, an in-situ electrochemical transformation strategy was performed to construct the atomically thin bismuthene nanosheets with rich and stabilized BiO bonds (OBi-ene) from Bi2O2S precursor for CO2 electroreduction to formate. Electrochemical and thermodynamic characterizations confirm that rich BiO bonds could greatly enhance the CO2 adsorption on catalyst surface, which significantly accelerates the initial electron-transfer step of CO2 electroreduction for forming the key CO2·- intermediate. Consequently, the OBi-ene catalyst exhibits both high Faraday efficiency (>90%) and cathodic energy efficiency (>60%) to produce formate at wide current range from 50 to 400 mA cm−2 in flow cell. Impressively, a large current density of 200 mA cm−2 can be achieved only at 2.98 V in a full cell. This work provides a feasible strategy to design Bi-based electrocatalysts for efficient CO2 electroreduction.

Large-Area Vertically Aligned Bismuthene Nanosheet Arrays from Galvanic Replacement Reaction for Efficient Electrochemical CO2 Conversion.

There is a lack of straightforward methods to prepare high-quality bismuthene nanosheets, or, even more challengingly, to grow their arrays due to the low melting point and high oxophilicity of bismuth. This synthetic obstacle has hindered their potential applications. In this work, it is demonstrated that the galvanic replacement reaction can do the trick. Under well-controlled conditions, large-area vertically aligned bismuthene nanosheet arrays are grown on Cu substrates of various shapes and sizes. The product features small nanosheet thickness of two to three atomic layers, large surface areas, and abundant porosity between nanosheets. Most remarkably, bismuthene nanosheet arrays grown on Cu foam can enable efficient CO2 reduction to formate with high Faradaic efficiency of >90%, large current density of 50mA cm-2 , and great stability.

Nanoparticles: Untying the Gordian Knot in Conventional Computed Tomography Imaging

X-ray computed tomography (CT) imaging plays an essential role in disease diagnosis due to its noninvasive, painless mode and superior penetration depth. However, the resolution of the soft tissue ...

Broadband saturated absorption properties of bismuthene nanosheets.

The nonlinear absorption properties of two-dimensional bismuthene nanosheets have great value for application in the photonics field. In this work, bismuthene nanosheets with a thickness of around 4 nm were prepared using the liquid phase exfoliation (LPE) method. The infrared waveband nonlinear absorption properties of bismuthene nanosheets were investigated using the open aperture Z-scan technique with four wavelengths of 950, 1064, 1200, and 1500 nm, respectively. Bismuthene nanosheets exhibited broadband saturated absorption (SA) properties at the infrared band. The lower saturated intensity indicated the advantages of bismuthene as a saturated absorber in the application of ultra-fast lasers in the infrared band.

Monoclinic Scheelite Bismuth Vanadate Derived Bismuthene Nanosheets with Rapid Kinetics for Electrochemically Reducing Carbon Dioxide to Formate

AbstractElectrochemical reduction of CO2 to high‐value chemical feedstocks, such as formate, is one of the most promising ways to alleviate the greenhouse effect. Unfortunately, the exploration of electrocatalysts with high activity and selectivity over a wide potential window (especially low potential for high current density) still remains a grand challenge. In this study, the fabrication of bismuthene nanosheets using an in‐situ electrochemical transformation strategy of monoclinic scheelite BiVO4 flakes is demonstrated. Catalyzing the CO2 electroreduction in 1 m KHCO3 aqueous solution, the bismuthene nanosheets exhibit a dramatically high formate Faradaic efficiency (FE) of ≈97.4% and a very large current density of −105.4 mA cm−2 at −1.0 V versus reversible hydrogen electrode. Significantly, over a record wide potential window of 750 mV from the initial −0.65 V to the applied minimum −1.4 V, the formate FEs of the bismuthene nanosheets are always higher than 90%, outperforming state‐of‐the‐art electrocatalysts. Both experimental and theoretical investigations reveal that, in comparison with •COOH and H• intermediates, the bismuthene nanosheets preferentially promote fast reaction kinetics towards HCOO•, which eventually accelerates the production of formate.

Sheet-structured bismuthene for near-infrared dual-wavelength harmonic mode-locking

Bismuthene with a similar layered lattice structure belonging to group VA is regarded as a kind of novel two-dimensional material and has excellent properties such as small indirect bandgap (less than 1 eV) and unique electronic properties, etc. Based on the large magnitude of third-order nonlinear susceptibility and high carrier motility, bismuthene can be considered as a promising material for various optoelectronics, electronics, and nonlinear optics. Compared with the mass research about the few-layer bismuthene, we focus on the characteristics and nonlinear optical properties of bismuthene nanosheets in this work. Bismuthene nanosheets present high modulation depth over 7.7%. The sheet-structured bismuthene as saturable absorbers (SAs) is a technically important issue in laser technology. Here, for the first time, it is demonstrated that bismuthene nanosheets can be served as an SA to readily generate a harmonic dual-wavelength mode-locked picosecond pulse in a highly nonlinear fiber laser. A harmonic mode-locked pulse order from 1st to 20th is obtained at the pump power from 43.2 to 201.5 mW. When the pump power is greater than 408 mW, a 52th harmonic dual-wavelength pulse (corresponding to the repetition of 208 MHz) has been obtained. This study demonstrates the bismuthene saturable absorption is an intrinsic property independent from the structural dimension. Our work attests the promise of bismuthene in optical communication, optical detecting, sensor systems, and material processing, etc.

Bismuthene nanosheets produced by ionic liquid assisted grinding exfoliation and their use for oxygen reduction reaction.

We report the simple synthesis of bismuthene nanosheets (BiNS) by ionic liquid assisted grinding exfoliation, followed by size selection sequential centrifugation steps for the first time. The exfoliation process results in the formation of self-assembled spherule-like superstructures with abundant edge sites, which are able to catalyze the oxygen reduction reaction (ORR) via a two-electron pathway, with a higher efficiency than the bulk Bismuth. We rationalize the enhanced ORR activity of the BiNS to: (i) the presence of 1 dimensional topological edge states, which provide strong conduction channels for electron hopping between the bismuth layers and (ii) the more active role of edge sites in facilitating O2 adsorption and dissociation of O–O bonds compared to the basal plane. The present study provides a pathway for employing 2D topological insulators as a new class of electrocatalysts for clean energy applications.

Soft-template assisted synthesis of hexagonal antimonene and bismuthene in colloidal solutions.

Monoelemental two-dimensional (2D) group-VA materials have received increasing interest due to their great potential in optoelectronic applications. Despite numerous efforts have been made for their syntheses, the development of effective and better controllable synthetic approaches for the preparation of monoelemental 2D group-VA materials is still in its infancy. In this work, we report a soft-template approach for the synthesis of multilayered antimonene and bismuthene nanosheets in colloidal solutions. We show that the prepared antimonene and bismuthene nanosheets possess a well-defined rhombohedral crystal structure with impressive stability. We elucidate a formation pathway for the 2D nanosheets with small-angle X-ray diffraction (XRD) analysis. We demonstrate that SbCl3 dissolves in alkyl phosphonic acids to form a lamellar structure initially, which is apt for the formation of the final 2D morphology. The present study introduces a general route to synthesizing monoelemental 2D group-VA materials in colloidal solutions and gives a deeper insight into their growth mechanism.