Journal: ACS Materials Letters

Abbreviation

ACS Materials Lett.

Publisher

American Chemical Society

Journal Volumes

ISSN

2639-4979

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Filters

2020 - 20245
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Publications1 - 5 of 5
  • Activated Metals to Generate Heat for Biomedical Applications
    Item type: Journal Article
    Remlova, Eva; Feig, Vivian R.; Kang, Ziliang; et al. (2023)
    ACS Materials Letters
    Delivering heat in vivo could enhance a wide range of biomedical therapeutic and diagnostic technologies, including long-term drug delivery devices and cancer treatments. To date, providing thermal energy is highly power-intensive, rendering it oftentimes inaccessible outside of clinical settings. We developed an in vivo heating method based on the exothermic reaction between liquid-metal-activated aluminum and water. After establishing a method for consistent activation, we characterized the heat generation capabilities with thermal imaging and heat flux measurements. We then demonstrated one application of this reaction: to thermally actuate a gastric resident device made from a shape-memory alloy called Nitinol. Finally, we highlight the advantages and future directions for leveraging this novel in situ heat generation method beyond the showcased example.
  • Recent Advances in Nickel-Based Perovskite Oxides for the Electrocatalytic Oxygen Evolution Reaction in Alkaline Electrolytes
    Item type: Review Article
    Falqueto, Juliana Bruneli; Hales, Natasha; Schimidt, Thomas J.; et al. (2024)
    ACS Materials Letters
    Perovskites ABO3 are very versatile catalysts that can change their structure in several ways to enhance their electrocatalytic properties. Among nickel-based perovskites, those containing lanthanum or alkaline earth elements at the A-site display notable potential for the oxygen evolution reaction (OER) in alkaline electrolytes. Properties of nickel-based perovskites include the formation of mixed nickel oxidation states and the remarkable ability to accommodate numerous oxygen vacancies within their lattice. Oxygen vacancy content is an effective method to boost the electrocatalytic performance, and nickelate perovskites include a fascinating family of materials that exhibit oriented lattice oxygen vacancies: the infinite layer nickelates. However, nickelate perovskites remain a relatively underexplored area of research, likely due to the challenges associate with their synthesis. A major challenge lies in understanding the dynamic self-reconstruction of nickel-based perovskites under OER conditions. Monitoring this self-reconstruction through operando characterization is essential for precisely unraveling the causes of catalyst transformation and understanding the OER mechanisms. Leveraging these findings enables the design of more effective catalysts. In this Perspective, we aim to provide a summary of recent advances, insights, and suggestions for the development of nickel-based perovskites for electrocatalytic OER in alkaline electrolytes.
  • Efficient Lone-Pair-Driven Luminescence: Structure–Property Relationships in Emissive 5s2 Metal Halides
    Item type: Review Article
    McCall, Kyle M.; Morad, Viktoriia; Benin, Bogdan Markovich; et al. (2020)
    ACS Materials Letters
    Low-dimensional metal halides have been the focus of intense investigations in recent years following the success of hybrid lead halide perovskites as optoelectronic materials. In particular, the light emission of low-dimensional halides based on the 5s2 cations Sn2+ and Sb3+ has found utility in a variety of applications complementary to those of the three-dimensional halide perovskites because of its unusual properties such as broadband character and highly temperature-dependent lifetime. These properties derive from the exceptional chemistry of the 5s2 lone pair, but the terminology and explanations given for such emission vary widely, hampering efforts to build a cohesive understanding of these materials that would lead to the development of efficient optoelectronic devices. In this Perspective, we provide a structural overview of these materials with a focus on the dynamics driven by the stereoactivity of the 5s2 lone pair to identify the structural features that enable strong emission. We unite the different theoretical models that have been able to explain the success of these bright 5s2 emission centers into a cohesive framework, which is then applied to the array of compounds recently developed by our group and other researchers, demonstrating its utility and generating a holistic picture of the field from the point of view of a materials chemist. We highlight those state-of-the-art materials and applications that demonstrate the unique capabilities of these versatile emissive centers and identify promising future directions in the field of low-dimensional 5s2 metal halides.
  • Supramolecular Approach for Fine-Tuning of the Bright Luminescence from Zero-Dimensional Antimony(III) Halides
    Item type: Journal Article
    Morad, Viktoriia; Yakunin, Sergii; Kovalenko, Maksym V. (2020)
    ACS Materials Letters
    Halides of ns2 metal ions have recently regained broad research interest as bright narrowband and broadband emitters. Sb(III) is particularly appealing for its oxidative stability (compared to Ge2+ and Sn2+) and low toxicity (compared to Pb2+). Square pyramidal SbX5 anion had thus far been the most common structural motif for realizing high luminescence efficiency, typically when cocrystallized with an organic cation. Luminescent hybrid organic–inorganic halides with octahedral coordination of Sb(III) remain understudied, whereas fully inorganic compounds show very limited structural engineerability. We show that the host–guest complexation of alkali metal cations with crown ethers fosters the formation of zero-dimensional Sb(III) halides and allows for adjusting the coordination number (5 or 6). The obtained compounds exhibit bright photoluminescence with quantum yields of up to 89% originating from self-trapped excitons, with emission energies, Stokes shifts, and luminescence lifetimes finely-adjustable by structural engineering. A combination of environmental stability and strong, intrinsic temperature-dependence of the luminescence lifetimes in the nanosecond-to-microsecond range nominate these compounds as highly potent luminophores for remote thermometry and thermography owing to their sensitivity range of 200–450 K and high specific sensitivities of 0.04 °C–1.
  • Biomimetic Porous MXene-Based Hydrogel for High-Performance and Multifunctional Electromagnetic Interference Shielding
    Item type: Journal Article
    Yang, Yunfei; Li, Bin; Wu, Na; et al. (2022)
    ACS Materials Letters
    Highly cross-linked hydrogels with water-enriched pores have outstanding potentials for multifunctional architectures mimicking the bio-logical materials with hierarchical structure in nature. Here, a type of transition metal carbide (Ti3C2 MXene)/poly(vinyl alcohol) (PVA) biomimetic hydrogels are manufactured via an ice-templated freezing followed by salting-out approach. In addition to high electrical conductivity and mechanical strength as well as ultraflexibility, a honeycomb-like aligned porous structure is successfully achieved. Thanks to the synergistic interactions among MXene, PVA, water, and biomimetic porous structure, the thin hydrogels show an excellent X-band electromagnetic interference (EMI) shielding effectiveness (SE) of 57 dB at a merely 0.86 vol % MXene content. EMI SE more than 50 dB in the ultrabroadband frequencies of 8.2-40 GHz, covering typical GHz frequency ranges, is accomplished. More importantly, via in situ controlling the water contents of the hydrogels, a quantitative influence of the water on EMI shielding performance was ascertained. Furthermore, a good strain sensing performance of the ultraflexible, wearable hydrogel contributes to the sensitive and reliable detections of human motions and smart coding. This work thus suggests an avenue for preparing robust, flexible, and multifunctional MXene-based biomimetic hydrogels toward high-performance EMI shields and wearable strain sensors.
Publications1 - 5 of 5