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The size-controlled synthesis of liquid metal nanoparticles is necessary in a variety of applications. Sonication is a common method for breaking down bulk liquid metals into small particles, yet the influence of critical factors such as liquid metal composition has remained elusive. Our study employs high-speed imaging to unravel the mechanism of liquid metal particle formation during mechanical agitation. Gallium-based liquid metals, with and without secondary metals of bismuth, indium, and tin, are analyzed to observe the effect of cavitation and surface eruption during sonication and particle release. The impact of the secondary metal inclusion is investigated on liquid metals' surface tension, solution turbidity, and size distribution of the generated particles. Our work evidences that there is an inverse relationship between the surface tension and the ability of liquid metals to be broken down by sonication. We show that even for 0.22 at. % of bismuth in gallium, the surface tension is significantly decreased from 558 to 417 mN/m (measured in Milli-Q water), resulting in an enhanced particle generation rate: 3.6 times increase in turbidity and â¼43% reduction in the size of particles for bismuth in gallium liquid alloy compared to liquid gallium for the same sonication duration. The effect of particles' size on the photocatalysis of the annealed particles is also presented to show the applicability of the process in a proof-of-concept demonstration. This work contributes to a broader understanding of the synthesis of nanoparticles, with controlled size and characteristics, via mechanical agitation of liquid metals for diverse applications.
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The emergence of ferroelectricity in two-dimensional (2D) metal oxides is a topic of significant technological interest; however, many 2D metal oxides lack intrinsic ferroelectric properties. Therefore, introducing asymmetry provides access to a broader range of 2D materials within the ferroelectric family. Here, the generation of asymmetry in 2D SnO by doping the material with Hf0.5Zr0.5O2 (HZO) is demonstrated. A liquid metal process as a doping strategy for the preparation of 2D HZO-doped SnO with robust ferroelectric characteristics is implemented. This technology takes advantage of the selective interface enrichment of molten Sn with HZO crystallites. Molecular dynamics simulations indicate a strong tendency of Hf and Zr atoms to migrate toward the surface of liquid metal and embed themselves within the growing oxide layer in the form of HZO. Thus, the liquid metal-based harvesting/doping technique is a feasible approach devised for producing novel 2D metal oxides with induced ferroelectric properties, represents a significant development for the prospects of random-access memories.
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The development of advanced solar energy technologies, which efficiently convert solar energy to heat and then to electricity, remains a significant challenge in the pursuit of clean energy production. Here, this challenge is addressed by designing a photothermal absorber composed of liquid gallium particles and a natural polyphenol-based coordination ink. The design of this composite takes advantage of the tuneable light absorption properties of the polyphenol inks and can also be applied onto flexible substrates. While the ink utilizes two types of coordination complexes to absorb light at different wavelengths, the liquid gallium particles with high thermal and electrical properties provide enhanced thermoelectric effect. As such, the photothermal composite exhibits a broad-spectrum light absorption and highly efficient solar-to-heat conversion. A thermoelectric generator coated with the photothermal composite exhibits an impressive voltage output of ≈185.3 mV when exposed to 1 Sun illumination, without requiring any optical concentration, which sets a new record for a power density at 345.5 µW cm-2 . This work showcases the synergistic combination of natural compound-based light-absorbing coordination complexes with liquid metals to achieve a strong photothermal effect and their integration into thermoelectric devices with powerful light harvesting capabilities.
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Over the course of the Coronavirus disease 2019 (COVID-19) pandemic, numerous complications have been documented. In this report, we have detailed an unexpected complication of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that occurred in a 73-year-old female patient who was simultaneously afflicted with mucormycosis and another unanticipated problem. Due to the lack of recovery of the patient after receiving mucormycosis treatment and continued fever, cough and hemoptysis, bronchoscopy was performed for her. During bronchoscopy, we encountered a foreign body that was the cause of the patient's fever, cough, and hemoptysis. Rigid bronchoscopy was performed and the foreign body was removed from the left main bronchus. The lack of a favorable treatment response after administering antifungal therapy suggested that the presence of a foreign body could potentially act as an underlying nidus, thus influencing the suboptimal therapeutic outcome. Mucormycosis is usually characterized by distinct radiological patterns. However, this case did not present predictable imaging findings, further complicating the diagnostic process associated with this invasive fungal infection.
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Liquid metal-electrolyte can offer electrochemically reducing interfaces for the self-deposition of low-dimensional nanomaterials. We show that implementing such interfaces from multiprecursors is a promising pathway for achieving nanostructured films with combinatory properties and functionalities. Here, we explored the liquid metal-driven interfacial growth of metal tellurides using eutectic gallium-indium (EGaIn) as the liquid metal and the cation pairs Ag+-HTeO2+ and Cu2+-HTeO2+ as the precursors. At the EGaIn-electrolyte interface, the precursors were reduced and self-deposited autogenously to form interconnected nanoparticle networks. The deposited materials consisted of metal telluride and tellurium with their relative abundance depending on the metal ion type (Ag+ and Cu2+) and the metal-to-tellurium ion ratios. When used as electrode modifiers, the synthesized materials increased the electroactive surface area of unmodified electrodes by over 10 times and demonstrated remarkable activity for model electrochemical reactions, including HexRu(III) responses and dopamine sensing. Our work reveals the promising potential of the liquid metal-templated deposition method for synthesizing complex material systems for electrochemical applications.
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Ferroelectrics possess a spontaneous polarization that is switchable by an electric field and is critical for the development of low-energy nanoelectronics and neuromorphic applications. However, apart from a few recent developments, the realization of switchable polarization in metal oxides with simpler structures has been a major challenge. Here, we demonstrate the presence of robust switchable polarization at the level of a single nanocrystallite in magnesium-doped zinc oxide thin films with polar wurtzite crystal structures. Using a combination of high-resolution scanning probe microscopy and spectroscopic techniques, voltage control of the polarization and the coupled electronic transport behavior revealing a giant resistance change of approximately 10000% is unveiled. Time- and frequency-resolved nanoscale measurements provide key insights into the polarization phenomenon and a 9-fold increase in the effective longitudinal piezoelectric coefficient. Our work thus constitutes a crucial step toward validating nanoscale ferroelectricity in polar wurtzites for use in advanced nanoelectronics and memory applications.
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Metallic nanoarchitectures hold immense value as functional materials across diverse applications. However, major challenges lie in effectively engineering their hierarchical porosity while achieving scalable fabrication at low processing temperatures. Here we present a liquid-metal solvent-based method for the nanoarchitecting and transformation of solid metals. This was achieved by reacting liquid gallium with solid metals to form crystalline entities. Nanoporous features were then created by selectively removing the less noble and comparatively softer gallium from the intermetallic crystals. By controlling the crystal growth and dealloying conditions, we realized the effective tuning of the micro-/nanoscale porosities. Proof-of-concept examples were shown by applying liquid gallium to solid copper, silver, gold, palladium, and platinum, while the strategy can be extended to a wider range of metals. This metallic-solvent-based route enables low-temperature fabrication of metallic nanoarchitectures with tailored porosity. By demonstrating large-surface-area and scalable hierarchical nanoporous metals, our work addresses the pressing demand for these materials in various sectors.
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The presence of pharmaceutical compounds in the environment poses a significant threat to human and aquatic animal health. Dexamethasone (DEX), a synthetic steroid hormone with endocrine-disrupting effects, is one such compound that needs to be effectively removed before discharging into the environment. This research presents a novel approach utilizing magnetically recyclable Fe3O4@NH2-MIL88B NRs as an efficient adsorbent for the treatment of DEX from aqueous solutions. The synthesized adsorbent was characterized by X-ray diffraction (XRD), scanning microscopy (SEM), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM), diffuse reflectance spectra (DRS), and Fourier transform infrared spectroscopy (FTIR). Response surface methodology based on central composite design (RSM-CCD) was employed to optimize DEX removal efficiency by determining the optimal conditions, including pH, adsorbent dose, time, and DEX concentration. Under the optimized conditions (pH: 5.53, adsorbent dose: 0.185 g/L, time: 16.068 min, and DEX concentration: 33.491 mg/L), Fe3O4@NH2-MIL88B NRs revealed remarkable DEX adsorption efficiency of 91 ± 1.34% and adsorption capacity of 180.01 mg/g. The Langmuir isotherm and pseudo-second-order kinetic model were found to fit well with the experimental data, indicating a monolayer and chemical adsorption process. Thermodynamic analysis revealed that the adsorption process was spontaneous and endothermic. The study also investigated the inhibitory effect of background ions on DEX removal by Fe3O4@NH2-MIL88B NRs. Magnesium exhibited superior competitive ability with dexamethasone to occupy the active sites of the adsorbent compared to other background ions. The reuse of the adsorbent over ten consecutive cycles resulted in a 39.46% decrease in removal efficiency. The Fe3O4@NH2-MIL88B NRs are surrounded by abundant amounts of functional groups and π-electrons bands that can play a key role in the adsorption and separation of DEX from aqueous environments. The promising results obtained under real conditions highlight the potential of Fe3O4@NH2-MIL88B NRs as a practical and efficient adsorbent for the removal of DEX and other similar corticosteroids from aqueous solutions.
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Gallium (Ga) is a low melting point metal in the liquid state in the biological environment which presents a unique combination of fluidity, softness, and metallic electrical and thermal properties. In this work, liquid Ga is proposed as a biocompatible electrode material for cell culture by electro-stimulation since the cytotoxicity of Ga is generally considered low and some Ga compounds have been reported to exhibit anti-bacterial and anti-inflammatory activities. Complementarily, polydopamine (PDA) was coated on liquid Ga to increase the attachment capability of cells on the liquid Ga electrode and provide enhanced biocompatibility. The liquid Ga layer could be readily painted at room temperature on a solid inert substrate, followed by the formation of a nanoscale PDA coating layer resulting in a conformable and biocompatible composite electrode. The PDA layer was shown to coordinate with Ga3+, which is sourced from liquid Ga, providing electrical conductivity in the cell culture medium. The PDA-Ga3+ composite acted as a conductive substrate for advanced electro-stimulation for cell culture methods of representative animal fibroblasts. The cell proliferation was observed to increase by â¼143% as compared to a standard glass coverslip at a low potential of 0.1 V of direct coupling stimulation. This novel PDA-Ga3+ composite has potential applications in cell culture and regenerative medicine.
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Galio , Polímeros , Animales , Polímeros/farmacología , Polímeros/química , Materiales Biocompatibles/farmacología , Galio/farmacología , Técnicas de Cultivo de CélulaRESUMEN
Liquid metal (LM) droplets are now used in many applications including catalysis, sensing, and flexible electronics. Consequently, the introduction of methods for on-demand alternating electronic properties of LMs is necessary. The active surface of LMs provides a unique environment for spontaneous chemical reactions that enable the formation of thin layers of functional materials for such modulations. Here, we showed the deposition of n-type MoOx and MoOxSy semiconductors on the surface of EGaIn LM droplets under mechanical agitation to successfully modulate their electronic structures. The "liquid solution"-"liquid metal" interaction resulted in the formation of oxide and oxysulfide layers on the surface of LM droplets. The comprehensive study of electronic and optical properties revealed a decrease in the band gap of the droplets after surface decoration with MoOx and MoOxSy, leading to deeper n-type doping of the materials. This method provides a facile procedure for engineering the electronic band structure of LM-based composites when they are necessary for various applications.
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Gallium (Ga) is a low melting point post-transition metal that, under mild mechanical agitation, can form micron and submicron-sized particles with combined fluid-like and metallic properties. In this work, an inorganic network of Ga liquid metal particles was synthesised via spontaneous formation of manganese (Mn) oxide species on their liquid metallic surfaces forming an all-inorganic composite. The micron-sized Ga particles formed by sonication were connected together by Mn oxide nanostructures spontaneously established from the reduction of a Mn salt in aqueous solution slightly above the melting point of Ga. The formed Mn oxide nanostructures were found to coalesce from the surface of the Ga particles into a continuous inorganic network. The morphology of the composites could be altered by varying the Mn salt concentration and by performing post-treatment annealing. The composites presented a shell of various Mn oxide nanostructures including wrinkled sheets, rods and nanoneedles, around spherical liquid Ga particles, and a liquid metal core. The photoelectric and optical properties of the composites were thoroughly characterised, which revealed decreasing bandgaps and valence band edge characteristics as a function of increased Mn oxide coverage. The photoluminescence properties of the composites could be also engineered by increasing the Mn oxide coverage. The all-inorganic liquid Ga composite could be formed via a straightforward reduction reaction of a Mn-rich salt at the surface of liquid Ga particles with tunable surface properties for future optoelectronic applications.
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In nature, snowflake ice crystals arrange themselves into diverse symmetrical six-sided structures. We show an analogy of this when zinc (Zn) dissolves and crystallizes in liquid gallium (Ga). The low-melting-temperature Ga is used as a "metallic solvent" to synthesize a range of flake-like Zn crystals. We extract these metallic crystals from the liquid metal solvent by reducing its surface tension using a combination of electrocapillary modulation and vacuum filtration. The liquid metal-grown crystals feature high morphological diversity and persistent symmetry. The concept is expanded to other single and binary metal solutes and Ga-based solvents, with the growth mechanisms elucidated through ab initio simulation of interfacial stability. This strategy offers general routes for creating highly crystalline, shape-controlled metallic or multimetallic fine structures from liquid metal solvents.
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Liquid metals can be surface activated to generate a controlled galvanic potential by immersing them in aqueous solutions. This creates energized liquid-liquid interfaces that can promote interfacial chemical reactions. Here we utilize this interfacial phenomenon of liquid metals to deposit thin films of tin-doped tellurium onto rigid and flexible substrates. This is accomplished by exposing liquid metals to a precursor solution of Sn2+ and HTeO2+ ions. The ability to paint liquid metals onto substrates enables us to fabricate supercapacitor electrodes of liquid metal films with an intimately connected surface layer of tin-doped tellurium. The tin-doped tellurium exhibits a pseudocapacitive behavior in 1.0 M Na2SO4 electrolyte and records a specific capacitance of 184.06 F·g-1 (5.74 mF·cm-2) at a scan rate of 10 mV·s-1. Flexible supercapacitor electrodes are also fabricated by painting liquid metals onto polypropylene sheets and subsequently depositing tin-doped tellurium thin films. These flexible electrodes show outstanding mechanical stability even when experiencing a complete 180° bend as well as exhibit high power and energy densities of 160 W·cm-3 and 31 mWh·cm-3, respectively. Overall, this study demonstrates the attractive features of liquid metals in creating energy storage devices and exemplifies their use as media for synthesizing electrochemically active materials.
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Amine-functionalized polymers (AFPs) are able to react with carbon dioxide (CO2) and are therefore useful in CO2 capture and sensing. To develop AFP-based CO2 sensors, it is critical to examine their electrical responses to CO2 over long periods of time, so that the device can be used consistently for measuring CO2 concentration. To this end, we synthesized poly(N-[3-(dimethylamino)propyl] methacrylamide) (pDMAPMAm) by free radical polymerization and tested its ability to behave as a CO2-responsive polymer in a transducer. The electrical response of this polymer to CO2 upon long exposure times was measured in both the aqueous and solid phases. Direct current resistance measurement tests on pDMAPMAm films printed along with the silver electrodes in the presence of CO2 at various concentrations reveal a two-region electrical response. Upon continuous exposure to different CO2 flow rates (at a constant pressure of 0.2 MPa), the resistance first decreased over time, reaching a minimum, followed by a gradual increase with further exposure to CO2. A similar trend is observed when CO2 is introduced to an aqueous solution of pDMAPMAm. The in situ monitoring of pH suggests that the change in resistance of pDMAPMAm can be attributed to the protonation of tertiary amine groups in the presence of CO2. This two-region response of pDMAPMAm is based on a proton-hopping mechanism and a change in the number of free amines when pDMAPMAm is exposed to various levels of CO2.
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Understanding the interfacial contacts between liquid metals and substrate materials is becoming increasingly important for the fast-rising liquid metal-enabled technologies. However, for such technologies, probing the contact behavior and interfacial charge transport has remained challenging due to the deformable nature of liquid metals and the presence of the surface oxide layer. Here, we encapsulate eutectic gallium indium (EGaIn) micro-/nanodroplets with tungsten trioxide (WO3) nanoparticles to form a WO3/EGaIn liquid metal marble network, in which the interfacial contact of the intrinsically semiconducting WO3 governs the charge transport. We investigate the interfacial structures and charge transport characteristics under different contact conditions and various gaseous environments. The results suggest that establishing a WO3/EGaIn heterostructure leads to near-ohmic contact behaviors and also the emergence of localized surface plasmon resonance. Density functional theory calculations of the WO3/EGaIn interface support the experiments by revealing atomistic attractions between EGaIn alloy and the O atoms from WO3, resulting in a Fermi level shift. We also show that the efficient interfacial charge transport of the liquid metal marble network results in an enhanced gas-sensing response. This work paves the way for the possibility of studying other liquid metal/semiconductor contacts for applications in soft electronics and optics.
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Transforming natural resources to energy sources, such as converting CH4 to H2 and carbon, at high efficiency and low cost is crucial for many industries and environmental sustainability. The high temperature requirement of CH4 conversion regarding many of the current methods remains a critical bottleneck for their practical uptake. Here we report an approach based on gallium (Ga) liquid metal droplets, Ni(OH)2 cocatalysts, and mechanical energy input that offers low-temperature and scalable CH4 conversion into H2 and carbon. Mainly driven by the triboelectric voltage, originating from the joint contributions of the cocatalysts during agitation, CH4 is converted at the Ga and Ni(OH)2 interface through nanotribo-electrochemical reaction pathways. The efficiency of the system is enhanced when the reaction is performed at an increased pressure. The dehydrogenation of other nongaseous hydrocarbons using this approach is also demonstrated. This technology presents a possible low energy route for CH4 conversion without involving high temperature and harsh operating conditions.
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Post-transition liquid metals (LMs) offer new opportunities for accessing exciting dynamics for nanomaterials. As entities with free electrons and ions as well as fluidity, LM-based nanomaterials are fundamentally different from their solid counterparts. The low melting points of most post-transition metals (less than 330 °C) allow for the formation of nanodroplets from bulk metal melts under mild mechanical and chemical conditions. At the nanoscale, these liquid state nanodroplets simultaneously offer high electrical and thermal conductivities, tunable reactivities and useful physicochemical properties. They also offer specific alloying and dealloying conditions for the formation of multi-elemental liquid based nanoalloys or the synthesis of engineered solid nanomaterials. To date, while only a few nanosized LM materials have been investigated, extraordinary properties have been observed for such systems. Multi-elemental nanoalloys have shown controllable homogeneous or heterogeneous core and surface compositions with interfacial ordering at the nanoscale. The interactions and synergies of nanosized LMs with polymeric, inorganic and bio-materials have also resulted in new compounds. This review highlights recent progress and future directions for the synthesis and applications of post-transition LMs and their alloys. The review presents the unique properties of these LM nanodroplets for developing functional materials for electronics, sensors, catalysts, energy systems, and nanomedicine and biomedical applications, as well as other functional systems engineered at the nanoscale.
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Metales , Nanoestructuras , Aleaciones/química , Electrónica , Metales/química , Nanoestructuras/química , NanotecnologíaRESUMEN
A green carbon capture and conversion technology offering scalability and economic viability for mitigating CO2 emissions is reported. The technology uses suspensions of gallium liquid metal to reduce CO2 into carbonaceous solid products and O2 at near room temperature. The nonpolar nature of the liquid gallium interface allows the solid products to instantaneously exfoliate, hence keeping active sites accessible. The solid co-contributor of silver-gallium rods ensures a cyclic sustainable process. The overall process relies on mechanical energy as the input, which drives nano-dimensional triboelectrochemical reactions. When a gallium/silver fluoride mix at 7:1 mass ratio is employed to create the reaction material, 92% efficiency is obtained at a remarkably low input energy of 230 kWh (excluding the energy used for dissolving CO2 ) for the capture and conversion of a tonne of CO2 . This green technology presents an economical solution for CO2 emissions.
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Molybdenum dioxide (MoO2), considering its near-metallic conductivity and surface plasmonic properties, is a great material for electronics, energy storage devices and biosensing. Yet to this day, room-temperature synthesis of large area MoO2, which allows deposition on arbitrary substrates, has remained a challenge. Due to their reactive interfaces and specific solubility conditions, gallium-based liquid metal alloys offer unique opportunities for synthesizing materials that can meet these challenges. Herein, a substrate-independent liquid metal-based method for the room temperature deposition and patterning of MoO2 is presented. By introducing a molybdate precursor to the surrounding of a eutectic gallium-indium alloy droplet, a uniform layer of hydrated molybdenum oxide (H2MoO3) is formed at the interface. This layer is then exfoliated and transferred onto a desired substrate. Utilizing the transferred H2MoO3 layer, a laser-writing technique is developed which selectively transforms this H2MoO3 into crystalline MoO2 and produces electrically conductive MoO2 patterns at room temperature. The electrical conductivity and plasmonic properties of the MoO2 are analyzed and demonstrated. The presented metal oxide room-temperature deposition and patterning method can find many applications in optoelectronics, sensing, and energy industries.
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Low melting point eutectic systems, such as the eutectic gallium-indium (EGaIn) alloy, offer great potential in the domain of nanometallurgy; however, many of their interfacial behaviors remain to be explored. Here, a compositional change of EGaIn nanoalloys triggered by polydopamine (PDA) coating is demonstrated. Incorporating PDA on the surface of EGaIn nanoalloys renders core-shell nanostructures that accompany Ga-In phase separation within the nanoalloys. The PDA shell keeps depleting the Ga3+ from the EGaIn nanoalloys when the synthesis proceeds, leading to a Ga3+-coordinated PDA coating and a smaller nanoalloy. During this process, the eutectic nanoalloys turn into non-eutectic systems that ultimately result in the solidification of In when Ga is fully depleted. The reaction of Ga3+-coordinated PDA-coated nanoalloys with nitrogen dioxide gas is presented as an example for demonstrating the functionality of such hybrid composites. The concept of phase-separating systems, with polymeric reservoirs, may lead to tailored materials and can be explored on a variety of post-transition metals.