Showing papers on "Bismuth published in 2019"
01 May 2019
TL;DR: Yin et al. as mentioned in this paper reported a strategy to simultaneously promote ENRR selectivity and activity using bismuth nanocrystals and potassium cations, and achieved high ammonia yield and Faradaic efficiency over 66% using Bismuth Nanocatalysts promoted by alkali cations.
Abstract: The electrochemical nitrogen reduction reaction (ENRR) can allow the production of ammonia from nitrogen and water under ambient conditions and is regarded as a sustainable alternative to the industrial Haber–Bosch process. However, electrocatalytic systems that selectively and efficiently catalyse nitrogen reduction remain elusive due to the strong competition with the hydrogen evolution reaction. Here, we report a strategy to simultaneously promote ENRR selectivity and activity using bismuth nanocrystals and potassium cations. Bismuth exhibits higher intrinsic ENRR activity than transition metals due to the strong interaction between the Bi 6p band and the N 2p orbitals. Potassium cations stabilize key nitrogen-reduction intermediates and regulate proton transfer to increase the selectivity. A high Faradaic efficiency of 66% and ammonia yield of 200 mmol g–1 h–1 (0.052 mmol cm–2 h–1) are obtained in aqueous electrolyte under ambient conditions. This strategy represents a general method to expand the library of catalysts and promoters for the selective electrochemical reduction of stable molecules. The electrochemical reduction of nitrogen to ammonia represents a challenge of major interest that would substantially decrease the burden of the energy-consuming Haber–Bosch process. Now, Yin, Yan, Zhang, Si and colleagues achieve high ammonia yield and Faradaic efficiency over 66% using bismuth nanocatalysts promoted by alkali cations.
551 citations
TL;DR: In this article, a two-dimensional mosaic bismuth nanosheet (Bi NS) was fabricated via an in situ electrochemical reduction process and exhibited favorable average ammonia yield and Faradaic efficiency as high as 2.54 ± 0.45% at −0.8 V versus reversible hydrogen electrode in 0.1 M Na2SO4.
Abstract: Electrochemical fixation of N2 to ammonia is a promising strategy to store renewable energy and mitigate greenhouse gas emissions. However, it usually suffers from extremely low ammonia yield and Faradaic efficiency because of the lack of efficient electrocatalysts and the competing hydrogen evolution reaction. Herein, we report that the semiconducting bismuth can be a promising catalyst for ambient electrocatalytic N2 reduction reaction (NRR). A two-dimensional mosaic bismuth nanosheet (Bi NS) was fabricated via an in situ electrochemical reduction process and exhibited favorable average ammonia yield and Faradaic efficiency as high as 2.54 ± 0.16 μgNH3 cm–2 h–1 (∼13.23 μg mgcat.–1 h–1) and 10.46 ± 1.45% at −0.8 V versus reversible hydrogen electrode in 0.1 M Na2SO4. The high NRR electrocatalytic activity of the Bi NS could be attributed to the sufficient exposure of edge sites coupled with effective p-orbital electron delocalization in the mosaic bismuth nanosheets. In addition, the semiconducting featu...
413 citations
TL;DR: Nanotube-derived bismuth is reported for electrocatalytic reduction of carbon dioxide to formate, with performance that is enhanced by defects, and coupled with silicon photocathodes and achieves high-performance photoelectrochemical carbon dioxide reduction.
Abstract: Formic acid (or formate) is suggested to be one of the most economically viable products from electrochemical carbon dioxide reduction. However, its commercial viability hinges on the development of highly active and selective electrocatalysts. Here we report that structural defects have a profound positive impact on the electrocatalytic performance of bismuth. Bismuth oxide double-walled nanotubes with fragmented surface are prepared as a template, and are cathodically converted to defective bismuth nanotubes. This converted electrocatalyst enables carbon dioxide reduction to formate with excellent activity, selectivity and stability. Most significantly, its current density reaches ~288 mA cm−2 at −0.61 V versus reversible hydrogen electrode within a flow cell reactor under ambient conditions. Using density functional theory calculations, the excellent activity and selectivity are rationalized as the outcome of abundant defective bismuth sites that stabilize the *OCHO intermediate. Furthermore, this electrocatalyst is coupled with silicon photocathodes and achieves high-performance photoelectrochemical carbon dioxide reduction. Carbon dioxide can be electrochemically reduced to form valuable chemical feedstocks, but efficiency of electrocatalysts should be improved. Here the authors report nanotube-derived bismuth for electrocatalytic reduction of carbon dioxide to formate, with performance that is enhanced by defects.
383 citations
TL;DR: In this article, the authors reported n-type magnesium bismuthide (Mg3Bi2)-based materials with a peak figure of merit (ZT) of 0.9 at 350 kelvin.
Abstract: Thermoelectric materials have a large Peltier effect, making them attractive for solid-state cooling applications. Bismuth telluride (Bi2Te3)–based alloys have remained the state-of-the-art room-temperature materials for many decades. However, cost partially limited wider use of thermoelectric cooling devices because of the large amounts of expensive tellurium required. We report n-type magnesium bismuthide (Mg3Bi2)–based materials with a peak figure of merit (ZT) of ~0.9 at 350 kelvin, which is comparable to the commercial bismuth telluride selenide (Bi2Te3–xSex) but much cheaper. A cooling device made of our material and p-type bismuth antimony telluride (Bi0.5Sb1.5Te3) has produced a large temperature difference of ~91 kelvin at the hot-side temperature of 350 kelvin. n-type Mg3Bi2-based materials are promising for thermoelectric cooling applications.
381 citations
274 citations
TL;DR: Bismuth might be a promising candidate for electrochemical N2 fixation because of its weak binding with H adatoms, which increases the selectivity and production rate, and is synthesized as an efficient noble-metal-free N2 reduction electrocatalyst via a low-temperature plasma bombardment approach.
Abstract: The electrochemical N2 fixation, which is far from practical application in aqueous solution under ambient conditions, is extremely challenging and requires a rational design of electrocatalytic centers. We observed that bismuth (Bi) might be a promising candidate for this task because of its weak binding with H adatoms, which increases the selectivity and production rate. Furthermore, we successfully synthesized defect-rich Bi nanoplates as an efficient noble-metal-free N2 reduction electrocatalyst via a low-temperature plasma bombardment approach. When exclusively using 1 H NMR measurements with N2 gas as a quantitative testing method, the defect-rich Bi(110) nanoplates achieved a 15 NH3 production rate of 5.453 μg mgBi -1 h-1 and a Faradaic efficiency of 11.68 % at -0.6 V vs. RHE in aqueous solution at ambient conditions.
209 citations
TL;DR: It is demonstrated that a chemically inert and structural impermeability bismuth electrode interlayer greatly increases the stability of unencapsulated perovskite solar cells under harsh conditions.
Abstract: Long-term stability remains a key issue impeding the commercialization of halide perovskite solar cells (HPVKSCs). The diffusion of molecules and ions causes irreversible degradation to photovoltaic device performance. Here, we demonstrate a facile strategy for producing highly stable HPVKSCs by using a thin but compact semimetal Bismuth interlayer. The Bismuth film acts as a robust permeation barrier that both insulates the perovskite from intrusion by undesirable external moisture and protects the metal electrode from iodine corrosion. The Bismuth-interlayer-based devices exhibit greatly improved stability when subjected to humidity, thermal and light stresses. The unencapsulated device retains 88% of its initial efficiency in ambient air in the dark for over 6000 h; the devices maintain 95% and 97% of their initial efficiencies after 85 °C thermal aging and light soaking in nitrogen atmosphere for 500 h, respectively. These sound stability parameters are among the best for planar structured HPVKSCs reported to date. Long term stability is a major barrier for the commercialization of halide perovskite solar cells. Here Wu et al. demonstrate that a chemically inert and structural impermeability bismuth electrode interlayer greatly increases the stability of unencapsulated perovskite solar cells under harsh conditions.
203 citations
TL;DR: In this paper, a facile strategy has been developed to obtain lattice-dislocated bismuth nanowires on copper foam (Cu foam@BiNW) through in situ electrochemical transformation of an electroless plated Bi film on copper foils after thermal treatment in air.
Abstract: Metallic bismuth (Bi) is an electrocatalyst that promotes CO2 reduction to formate. However, a substantial overpotential is needed to achieve a high formate faradaic efficiency along with a large catalytic current density, and this hinders its practical application. In this work, a facile strategy has been developed to obtain lattice-dislocated Bi nanowires on copper foam (Cu foam@BiNW) through in situ electrochemical transformation of an electroless plated Bi film on copper foam after thermal treatment in air. The Cu foam@BiNW is found to be a highly active electrocatalyst for CO2 reduction to formate at a low overpotential, reaching a faradaic efficiency for formate (FEformate) of 95% and a formate partial current density of ∼15 mA cm−2 at −0.69 V vs. RHE. High FEformate values of above 93% were also maintained over a potential range from −0.69 V to −0.99 V vs. RHE. A Fourier transformed ac voltammetric study revealed that unlike other Bi materials, the rate determining step for CO2 reduction on the Cu foam@BiNW electrode is the reduction of protonated CO2˙− radical anion, which indicates the presence of new catalytic active sites on the BiNWs. The high CO2 reduction activity of the Cu foam@BiNW electrode is attributed to the high intrinsic activity arising from the presence of crystal lattice dislocations on the twisted Bi nanowires and the large catalytic surface area associated with the porous structure. This work demonstrates the use of crystal defect engineering to improve the efficiency of electrocatalytic CO2 reduction on Bi metal.
198 citations
TL;DR: The Bi@C composite delivers outstanding sodium-storage performance with an ultralong cycle life of 30 000 cycles at a high current density and an excellent rate capability of 71% capacity retention at an ultrahigh current rate.
Abstract: Bismuth has emerged as a promising anode material for sodium-ion batteries (SIBs), owing to its high capacity and suitable operating potential. However, large volume changes during alloying/dealloying processes lead to poor cycling performance. Herein, bismuth nanoparticle@carbon (Bi@C) composite is prepared via a facile annealing method using a commercial coordination compound precursor of bismuth citrate. The composite has a uniform structure with Bi nanoparticles embedded within a carbon framework. The nanosized structure ensures a fast kinetics and efficient alleviation of stress/strain caused by the volume change, and the resilient and conductive carbon matrix provides an interconnected electron transportation pathway. The Bi@C composite delivers outstanding sodium-storage performance with an ultralong cycle life of 30 000 cycles at a high current density of 8 A g-1 and an excellent rate capability of 71% capacity retention at an ultrahigh current rate of 60 A g-1 . Even at a high mass loading of 11.5 mg cm-2 , a stable reversible capacity of 280 mA h g-1 can be obtained after 200 cycles. More importantly, full SIBs by pairing with a Na3 V2 (PO4 )3 cathode demonstrates superior performance. Combining the facile synthesis and the commercial precursor, the exceptional performance makes the Bi@C composite very promising for practical large-scale applications.
179 citations
TL;DR: In this paper, a series of recent fabrication methods for various dimensional nano structures of bismuth tungstate are presented, including morphological manipulation, doping or substitution, solid solution fabrication, and compound formation.
166 citations
TL;DR: According to electron paramagnetic resonance (EPR) and diffuse-reflectance infrared spectra, a reaction mechanism for photoreduction of CO2 via Bi-based PeNC photocatalysts to form CO, CH4 and other possible side products is proposed.
Abstract: We report here a series of nontoxic and stable bismuth-based perovskite nanocrystals (PeNCs) with applications for photocatalytic reduction of carbon dioxide to methane and carbon monoxide. Three bismuth-based PeNCs of general chemical formulas A3Bi2I9, in which cation A+ = Rb+ or Cs+ or CH3NH3+ (MA+), were synthesized with a novel ultrasonication top-down method. PeNC of Cs3Bi2I9 had the best photocatalytic activity for the reduction of CO2 at the gas-solid interface with formation yields 14.9 μmol g-1 of methane and 77.6 μmol g-1 of CO, representing a much more effective catalyst than TiO2 (P25) under the same experimental conditions. The products of the photocatalytic reactions were analyzed using a gas chromatograph coupled with a mass spectrometer. According to electron paramagnetic resonance and diffuse-reflectance infrared spectra, we propose a reaction mechanism for photoreduction of CO2 via Bi-based PeNC photocatalysts to form CO, CH4, and other possible side products.
TL;DR: This is the first example of 0D perovskites with broadband emission spanning the entire visible spectrum, and (C8 NH12 )4 Bi0.57 Sb0.43 Br7 ⋅H2 O exhibits excellent humidity and light stability.
Abstract: Lead-free zero-dimensional (0D) organic-inorganic metal halide perovskites have recently attracted increasing attention for their excellent photoluminescence properties and chemical stability. Here, we report the synthesis and characterization of an air-stable 0D mixed metal halide perovskite (C8 NH12 )4 Bi0.57 Sb0.43 Br7 ⋅H2 O, in which individual [BiBr6 ]3- and [SbBr6 ]3- octahedral units are completely isolated and surrounded by the large organic cation C8 H12 N+ . Upon photoexcitation, the bulk crystals exhibit ultra-broadband emission ranging from 400 to 850 nm, which originates from both free excitons and self-trapped excitons. This is the first example of 0D perovskites with broadband emission spanning the entire visible spectrum. In addition, (C8 NH12 )4 Bi0.57 Sb0.43 Br7 ⋅H2 O exhibits excellent humidity and light stability. These findings present a new direction towards the design of environmentally-friendly, high-performance 0D perovskite light emitters.
TL;DR: In this article, bismuth rich Bi4O5B2 hollow microspheres are designed as a robust photocatalyst for efficient CO2 reduction, and the local charge arrangement and electronic structure are tuned so as to achieve an exceptional efficiency of photocatalytic CO2 conversion into CO (3.16μmolg−1.1
TL;DR: In this paper, a few-layer bismuthene with a large aspect ratio is synthesized to relieve the expansion strain along the z-axis, and a free-standing bissuthene/graphene composite electrode with tunable thickness achieves a strikingly stable and high areal sodium storage capacity of 12.1 mAh cm-2, which greatly exceeds that of most reported electrode materials.
Abstract: Bismuth is a promising anode material for state-of-the-art rechargeable batteries due to its high theoretical volumetric capacity and relatively low working potential. However, its charge storage mechanism is unclear, hindering further improvement of the cell performance. Here, using in situ transmission electron microscopy and X-ray diffraction techniques as well as theoretical analysis, it is found that a large anisotropic volume expansion of 142% occurs along the z-axis largely due to the alloy reaction during sodiation, significantly reducing the electrochemical performance of bismuth electrodes. To address this problem, ultrathin few-layer bismuthene with a large aspect ratio is rationally synthesized, and can relieve the expansion strain along the z-axis. A free-standing bismuthene/graphene composite electrode with tunable thickness achieves a strikingly stable and high areal sodium storage capacity of 12.1 mAh cm-2 , which greatly exceeds that of most reported electrode materials. The clarification of the charge storage mechanism and the superior areal capacity achieved should facilitate the development of bismuth-based high-performance anodes for practical electrochemical energy-storage applications.
TL;DR: Rational synthesis of Rayleigh-instability-induced bismuth nanorods encapsulated in N-doped carbon nanotubes (Bi@N-C) using Bi2S3 nanobelts as the template for high-performance SIB is presented.
Abstract: Sodium-ion battery (SIB) as one of the most promising large-scale energy storage devices has drawn great attention in recent years. However, the development of SIBs is limited by the lacking of proper anodes with long cycling lifespans and large reversible capacities. Here we present rational synthesis of Rayleigh-instability-induced bismuth nanorods encapsulated in N-doped carbon nanotubes (Bi@N-C) using Bi2S3 nanobelts as the template for high-performance SIB. The Bi@N-C electrode delivers superior sodium storage performance in half cells, including a high specific capacity (410 mA h g-1 at 50 mA g-1), long cycling lifespan (1000 cycles), and superior rate capability (368 mA h g-1 at 2 A g-1). When coupled with homemade Na3V2(PO4)3/C in full cells, this electrode also exhibits excellent performances with high power density of 1190 W kg-1 and energy density of 119 Wh kg-1total. The exceptional performance of Bi@N-C is ascribed to the unique nanorod@nanotube structure, which can accommodate volume expansion of Bi during cycling and stabilize the solid electrolyte interphase layer and improve the electronic conductivity.
TL;DR: The failure mechanism of Bi nanorods and the protective effect of the carbon shell are revealed by ex situ TEM, which illuminates the decreasing tendency in the initial 10-20 cycles and the subsequent stable trend of cyclic performance.
Abstract: As an anode for lithium-ion batteries, metallic bismuth (Bi) can provide a superb volumetric capacity of 3800 mA h cm–3, showing perspective value for application. It is a pity that the severe volu...
TL;DR: Bismuth vacancies are engineered into BiOBr through ultrathin structure control and employed to tune the photocatalytic CO2 reduction and offer new opportunities for designing of surface metal vacancies to optimize the CO2 photoreduction performances.
Abstract: Surface defects in semiconductors have a significant role to tune the photocatalytic reactions. However, the dominant studied defect type is oxygen vacancy, and metal cation vacancies are seldom ex...
TL;DR: In situ transmission electron microscopy is used to disclose the structure and phase transitions of layered bismuth (few-layer bism Ruth nanosheets) during Na+ intercalation and alloying processes and finds that the metastable c-Na3Bi devotes to buffer the dramatic structure changes from thermodynamic stable h-Na2Bi, which unveils the origin of volume expansion for bismUTH and has important consequences for 2D in-plane structure.
Abstract: Bismuth has garnered tremendous interest for Na-ion batteries (NIBs) due to potentially high volumetric capacity. Yet, the bismuth upon sodiation/desodiation experiencing structure and phase transitions remains unclear, which sets a challenge for accessing nanotechnology and nanofabrication to achieve its applicability. Here, we use in situ transmission electron microscopy to disclose the structure and phase transitions of layered bismuth (few-layer bismuth nanosheets) during Na+ intercalation and alloying processes. Multistep phase transitions from Bi → NaBi → c-Na3Bi (cubic) → h-Na3Bi (hexagonal) are clearly identified, during which the Na+ migration from interlayer to in-plane evokes the structure transition from ABCABC stacking type of c-Na3Bi to ABABAB stacking type of h-Na3Bi. It is found that the metastable c-Na3Bi devotes to buffer the dramatic structure changes from thermodynamic stable h-Na3Bi, which unveils the origin of volume expansion for bismuth and has important consequences for 2D in-plan...
TL;DR: In this article, the structural and shielding properties of bismuth-boro-tellurite glass were studied using Fourier Transform Infrared (FTIR) and Lead Equivalent Thickness measurement (LET), respectively.
Abstract: Boro-tellurite glasses have recently been attracting the attention of several researchers as a tremendous optical device and shielding material. In this work, boro-tellurite glasses with bismuth oxide (Bi2O3) have been synthesized by melt quenching technique. The structural and shielding property changes after adding of bismuth oxide in boro-tellurite glass were studied using Fourier Transform Infrared (FTIR) and Lead Equivalent Thickness measurement (LET), respectively. The results show that the bismuth oxide increases glass density, changes the glass structure, and increases the radiation shielding properties. Changes in the glass structure are due to atomic rearrangements and formation of non-bridging oxygen (NBO). The density of boro-tellurite glass system increased up to 97% when Bi2O3 content increased, which is due to the high molecular weight of Bi2O3 and the increasing number of NBO atoms in the glass structure. In addition, the mass attenuation coefficient of the glass system increases as Bi2O3 concentration increases and the half value layer and mean free path show that present glass better than some standard concretes and commercial radiation shielding glasses. Current results demonstrated the advantages of bismuth-boro-tellurite glass as a new candidate of gamma radiation shielding material in selected energy range.
08 Aug 2019
TL;DR: In this article, a non-toxic methyl-acetate solution processed (CH3NH3)3Bi2I9 films were employed to fabricate lead-free, bismuth-based perovskite solar cells on mesoporous TiO2 architecture using a sustainable route.
Abstract: The very fast evolution in certified efficiency of lead-halide organic-inorganic perovskite solar cells to 24.2%, on par and even surpassing the record for polycrystalline silicon solar cells (22.3%), bears the promise of a new era in photovoltaics and revitalisation of thin film solar cell technologies. However, the presence of toxic lead and particularly toxic solvents during the fabrication process makes large-scale manufacturing of perovskite solar cells challenging due to legislation and environment issues. For lead-free alternatives, non-toxic tin, antimony and bismuth based solar cells still rely on up-scalable fabrication processes that employ toxic solvents. Here we employ non-toxic methyl-acetate solution processed (CH3NH3)3Bi2I9 films to fabricate lead-free, bismuth based (CH3NH3)3Bi2I9 perovskites on mesoporous TiO2 architecture using a sustainable route. Optoelectronic characterization, X-ray diffraction and electron microscopy show that the route can provide homogeneous and good quality (CH3NH3)3Bi2I9 films. Fine-tuning the perovskite/hole transport layer interface by the use of conventional 2,2′,7,7′-tetrakis (N,N′-di-p-methoxyphenylamino)−9,9′-spirbiuorene, known as Spiro-OMeTAD, and poly(3-hexylthiophene-2,5-diyl - P3HT as hole transporting materials, yields power conversion efficiencies of 1.12% and 1.62% under 1 sun illumination. Devices prepared using poly(3-hexylthiophene-2,5-diyl hole transport layer shown 300 h of stability under continuous 1 sun illumination, without the use of an ultra violet-filter. Perovskites are widely studied as components of solar cells but their synthesis often involves toxic reagents. Here lead-free bismuth-based perovskites are synthesised using a non-toxic solvent and shown to achieve power conversion efficiencies of up to 1.62 % under 1 sun illumination for up to 300 h.
TL;DR: The main mechanism research methods, such as in situ Fourier transform infrared (FTIR) spectroscopy and theoretical calculations, are presented and the main challenges and research trends reported in studies of Bi-based photocatalysts for photoc atalytic CO2 conversion are discussed and summarized.
Abstract: Photocatalytic CO2 conversion into solar fuels is an effective means for simultaneously solving both the greenhouse effect and energy crisis. In the past ten years, bismuth-based photocatalysts for environmental remediation have experienced a golden period of development. However, solar photocatalytic CO2 conversion has only been developed over the past five years and, until now, no reviews have been published on bismuth-based photocatalysts for the photocatalytic conversion of CO2 . For the first time, solar photocatalytic CO2 conversion systems are reviewed herein. Synthetic methods and photocatalytic CO2 performances of bismuth-based photocatalysts, including Sillen-structured BiOX (X=Cl, Br, I); Aurivillius-structured Bi2 MO6 (M=Mo, W); and Scheelite-structured BiVO4 , Bi2 S3 , BiYO3 , and BiOIO3 , are summarized. In addition, activity-enhancing strategies for this photocatalyst family, including oxygen vacancies, bismuth-rich strategy, facet control, conventional type II heterojunction, Z-scheme heterojunction, and cocatalyst deposition, are reviewed. Finally, the main mechanistic research methods, such as in situ FTIR spectroscopy and theoretical calculations, are presented. Challenges and research trends reported in studies of bismuth-based photocatalysts for photocatalytic CO2 conversion are discussed and summarized.
TL;DR: In this paper, a hot-pressing-based perovskite-type ceramics were used to explore energy storage performance via the HP technique, and the results showed that the recoverable energy storage density (WR = 3.14 J cm−3) for the HP sample is more than two times larger than that of the conventional sintering (CS) one.
Abstract: Currently, bismuth-based perovskite-type ceramics are considered as promising species in energy storage applications because of easy phase- and micro/macro-structure modulations and high performances. In this work, the composition dependent phase structure and ferroelectric properties of novel Bi0.5K0.5TiO3–Ba(Mg1/3Nb2/3)O3 (BKT–BMN) ceramics are studied. Relaxor properties are gradually enhanced with increasing BMN content. The BKT–0.15BMN composition is selected to further explore energy storage performance via the hot-pressing (HP) technique. The results show that the recoverable energy storage density (WR = 3.14 J cm−3) for the HP sample is more than two times larger than that of the conventional sintering (CS) one. The outstanding WR also exhibits super stability against temperature and frequency variations. Besides, the energy storage efficiency (η) is up to 83.7% for the HP sample. In particular, the stored energy can be released in a very short time of ∼0.12 μs at room temperature, indicating a fast discharging speed for the HP sample. The enhanced performance is due to the decrease of grain size and the increase of grain boundaries, the mechanism underlying the microstructure effect on the breakdown strength (BDS) value is disclosed by numerical simulations (COMSOL). This work not only enriches the bismuth-based ceramic systems in pulsed power applications, but also deepens the understanding of the intrinsic mechanism of a refined microstructure that boosts energy storage performance.
TL;DR: The method that was realized in this study is valuable for PbBiO2I/Bi5O7I/g-C3N4 synthesis and CV dye photocatalytic degradation for future applications in environmental pollution regulation and also describes possible photodegradation mechanisms.
TL;DR: A study of the PtSb system showed that the tetrahexahedron shape resulted from the evaporative removal of Sb from the initial alloy—a shape-regulating process fundamentally different from solution-phase, ligand-dependent processes.
Abstract: Tetrahexahedral particles (~10 to ~500 nanometers) composed of platinum (Pt), palladium, rhodium, nickel, and cobalt, as well as a library of bimetallic compositions, were synthesized on silicon wafers and on catalytic supports by a ligand-free, solid-state reaction that used trace elements [antimony (Sb), bismuth (Bi), lead, or tellurium] to stabilize high-index facets. Both simulation and experiment confirmed that this method stabilized the {210} planes. A study of the PtSb system showed that the tetrahexahedron shape resulted from the evaporative removal of Sb from the initial alloy-a shape-regulating process fundamentally different from solution-phase, ligand-dependent processes. The current density at a fixed potential for the electro-oxidation of formic acid with a commercial Pt/carbon catalyst increased by a factor of 20 after transformation with Bi into tetrahexahedral particles.
TL;DR: A carbon fiber supported binder‐free electrode consisting of bismuth and carbon composite is designed, which demonstrates with remarkable reversibility during sodiation and desodiation of large‐sized Na+ ion in electrode materials.
Abstract: The inferior tolerance with reversible accommodation of large-sized Na+ ion in electrode materials has plagued the adaptability of sodium-ion chemistry. The sluggish diffusion kinetics of Na+ also baffles the desirability. Herein, a carbon fiber supported binder-free electrode consisting of bismuth and carbon composite is designed. Well-confined bismuth nanodots are synthesized by replacing cobalt in the metal-organic frameworks (MOF)-derived, nitrogen-doped carbon arrays, which are demonstrated with remarkable reversibility during sodiation and desodiation. Cobalt species in the pristine MOF catalyze the graphitization around organic components in calcination, generating a highly conductive network in which the bismuth is to be embedded. The uniformly dispersed bismuth nanodots provide plenty boundaries and abundant active sites in the carbon arrays, where fast sodium storage kinetics are realized to contribute extra capacity and excellent rate performance.
TL;DR: In this article, a two-step solvothermal method was used to synthesize a bismuth sphere doped g-C3N4 nanohybrid, which demonstrated a H2 evolution rate of 35.9 µmol/h under visible light.
TL;DR: In vitro and in vivo studies demonstrate the promising photodynamic property of BPZP, together with their photothermal and CT imaging performance.
Abstract: Bismuth (Bi)-based nanomaterials (NMs) are widely used for computed tomography (CT) imaging guided photothermal therapy, however, the photodynamic property is hardly exhibited by these NMs due to the fast electron-hole recombination within their narrow bandgap. Herein, a sophisticated nanosystem is designed to endow bismuth sulfide (Bi2 S3 ) nanorods (NRs) with potent photodynamic property. Zinc protoporphyrin IX (ZP) is linked to Bi2 S3 NRs through a thermoresponsive polymer to form BPZP nanosystems. The stretching ZP could prebind to the active site of heme oxygenase-1 overexpressed in cancer cells, suppressing the cellular antioxidant defense capability. Upon NIR laser irradiation, the heat released from Bi2 S3 NRs could retract the polymer and drive ZP to the proximity of Bi2 S3 NRs, facilitating an efficient electron-hole separation in ZP and Bi2 S3 NRs, and leading to reactive oxygen species generation. In vitro and in vivo studies demonstrate the promising photodynamic property of BPZP, together with their photothermal and CT imaging performance.
TL;DR: Nitrogen and bismuth incorporation into TiO2 via PEO can be considered a promising alternative for dental implant application with antibacterial properties in darkness, with a stronger effect after visible-light application.
Abstract: Biofilm-associated diseases are one of the main causes of implant failure. Currently, the development of implant surface treatment goes beyond the osseointegration process and focuses on the creation of surfaces with antimicrobial action and with the possibility to be re-activated (i.e., light source activation). Titanium dioxide (TiO2), an excellent photocatalyst used for photocatalytic antibacterial applications, could be a great alternative, but its efficiency is limited to the ultraviolet (UV) range of the electromagnetic spectrum. Since UV radiation has carcinogenic potential, we created a functional TiO2 coating codoped with nitrogen and bismuth via the plasma electrolytic oxidation (PEO) of titanium to achieve an antibacterial effect under visible light with re-activation potential. A complex surface topography was demonstrated by scanning electron microscopy and three-dimensional confocal laser scanning microscopy. Additionally, PEO-treated surfaces showed greater hydrophilicity and albumin adsorption compared to control, untreated titanium. Bismuth incorporation shifted the band gap of TiO2 to the visible region and facilitated higher degradation of methyl orange (MO) in the dark, with a greater reduction in the concentration of MO after visible-light irradiation even after 72 h of aging. These results were consistent with the in vitro antibacterial effect, where samples with nitrogen and bismuth in their composition showed the greatest bacterial reduction after 24 h of dual-species biofilm formation ( Streptococcus sanguinis and Actinomyces naeslundii) in darkness with a superior effect at 30 min of visible-light irradiation. In addition, such a coating presents reusable photocatalytic potential and good biocompatibility by presenting a noncytotoxicity effect on human gingival fibroblast cells. Therefore, nitrogen and bismuth incorporation into TiO2 via PEO can be considered a promising alternative for dental implant application with antibacterial properties in darkness, with a stronger effect after visible-light application.
TL;DR: A highly flexible inkjet-printed thermoelectric energy generators (TEG) that does not diminish even after multiple bending experiments around a tight radius of curvature is reported, a step towards a fully functional wearable TEG device.
Abstract: Solution phase printing of nanomaterials is becoming increasingly important for the creation of scalable flexible electronics including those associated with biomedical and energy harvesting applications. However, the use of solution-phase printed thermoelectric energy generators (TEGs) has been minimally explored. Herein we report a highly flexible inkjet-printed TEG. Bismuth telluride (Bi2Te3) and bismuth antimony telluride (Bi0.5Sb1.5Te3) nanowires (NWs) are inkjet printed onto polyimide to form n-type and p-type legs for the TEGs. A post-print thermal annealing process is used to increase the thermoelectric performance of the printed NWs while eutectic gallium–indium (EGaIn) liquid metal contacts electrically connect the TEG legs in series. Annealing conditions for the combination of p/n legs are examined to maximize the thermoelectric efficiency of the TEG prototype. The maximum power factor was found to be 180 μW m−1 K−2 and 110 μW m−1 K−2 for the Bi2Te3 and Bi0.5Sb1.5Te3 nanowires respectively. A maximum power for the fully printed TEG device measured 127 nW at a 32.5 K temperature difference. The performance of the TEG device does not diminish even after multiple bending experiments (up to 50 times) around a tight radius of curvature (rod-dia. 11 mm). Hence this inkjet-printed flexible TEG is a step towards a fully functional wearable TEG device.
TL;DR: In this paper, a critical review summarizes recent progress in the design and tailoring of diversified Bi-based ultrathin materials for various photocatalytic applications, such as crystal facet control, bismuth enrichment strategy, surface adjustment, heteroatom doping, defect engineering, co-catalyst modification, and utilization of solid solutions, single atoms, and heterojunctions.
Abstract: The emerging ultrathin materials with a suitable energy band structure have been regarded as a new type of photocatalyst. Among them, bismuth-based ultrathin materials display intriguing photocatalytic performance due to the unique structural and electronic properties, strong light response and appealing energy band structure. This critical review summarizes recent progress in the design and tailoring of diversified Bi-based ultrathin materials for various photocatalytic applications. We start with the introduction from the crystal structure, materials design and synthesis of various Bi-based ultrathin photocatalysts, such as bismuth oxide, bismuth oxyhalides, Bi2WO6, Bi2MoO6, BiVO4 and so on. Then, strategies for local atomic arrangement, electronic structure, and carrier concentration tuning, so as to boost the performance, are summarized, such as crystal facet control, bismuth-enrichment strategy, surface adjustment, heteroatom doping, defect engineering, co-catalyst modification, and utilization of solid solutions, single atoms, and heterojunctions. Furthermore, advancements of versatile photocatalytic applications over Bi-based ultrathin materials are discussed, including oxygen evolution, hydrogen evolution, organic syntheses, CO2 reduction, N2 reduction, and pollutant removal, with an emphasis on the structure–activity relationship. Finally, the existing challenges and future research opportunities are also presented.