Science and Technology of Advanced Materials最新文献

3D printing has emerged as a highly efficient process for fabricating electrodes in hydrogen evolution through water splitting, whereas metals are the most popular choice of materials in hydrogen evolution reactions (HER) due to their catalytic activity. However, current 3D printing solutions face challenges, including high cost, low surface area, and sub-optimal performance. In this work, we introduce metal-deposited 3D printed pyrolytic carbon (PyC) as a facile and cost-effective HER electrode. We adopt an integrated approach of resin 3D printing, pyrolysis, and electrochemical metal deposition. 3D printing of a resin and its subsequent pyrolysis led to 3D complex architectures of the conductive substrate, facilitating the electrochemical metal deposition and leading to layered 3D metal architecture. Both monolayers of metals (such as copper and nickel) and bi-metallic 3D PyC structures are demonstrated. Each metal layer thickness ranges from 6 to10 µm. The metal coatings, particularly the bi-metallic configurations, result in achieving significantly higher mechanical properties under compressive loading and improved electrical properties due to the synergistic contributions from each metal counterpart. The metalized PyC structures are further demonstrated for HER catalysts, contributing to the development of highly efficient and durable catalyst systems for hydrogen production. Among the materials studied here, Ni@Cu bimetallic 3D PyC electrodes are particularly well-suited, demonstrating a low HER overpotential value of 264 mV (100 mA/cm², KOH (1 M)) with corresponding Tafel slopes of 107 mV/dec, with exceptional stability during a 10 h operation at a high applied current of -50 mA/cm².

This review presents computational and machine learning methodologies developed during a 5-year research project on proton-conducting oxides. The main goal was to develop methodologies that could assist in materials discovery or provide new insights into complex proton-conducting oxides. Through these methodologies, three new proton-conducting oxides, including both perovskite and non-perovskites, have been discovered. In terms of gaining insights, octahedral tilt/distortions and oxygen affinity are found to play a critical role in determining proton diffusivities and conductivities in doped barium zirconates. Replica exchange Monte Carlo approach has enabled to reveal realistic defect configurations, hydration behavior, and their temperature dependence in oxides. Our approach 'Materials discovery through interpretation', which integrates new insights or tendencies obtained from computations and experiments to sequential explorations of materials, has also identified perovskites that exhibit proton conductivity exceeding 0.01 S/cm and high chemical stability at 300 $\circ$ C.

As an alternative to conventional plastic dishes, the interface between water-immiscible hydrophobic fluids, such as perfluorocarbons and silicones, permits cell adhesion and growth. Thus, it is expected to replace the petroleum-derived products in a sustainable society. However, most hydrophobic fluids are cytotoxic, which limits the range of mechanical and chemical cues exposed to the cells. Using a data-driven approach, this study aimed to identify non-cytotoxic ionic liquids (ILs) as fluid culture platforms to take advantage of their 'designer' nature for broadening the possible physicochemical ranges exposed to cells and their repeated use owing to their high heat stability before their biological applications. The new candidates within the readily synthesized ammonium-type ILs were identified through the active cycle of regression and a limited number of cytotoxicity tests. Structure - cytotoxicity analysis indicated that the presence of multiple long alkyl branches was critical for low cytotoxicity. Particularly, we successfully cultured human mesenchymal stem cells (hMSCs) at the trihexylethylammonium trifluoromethylsulfonylimide interface and repeated their use after solvent extraction and heat sterilization. This study identified non-cytotoxic ILs that fulfill plastics' 3 R (Reduce, Recycle, and Replace) requirements and opens new avenues for hMSC fate manipulation through mechanotransduction.

This study investigates the compositional analysis and growth of β-(In _x Ga_1-x )₂O₃ thin films on (010) β-Ga₂O₃ substrates using mist chemical vapor deposition (CVD), including the effects of the growth temperature. We investigated the correlation between In composition and b-axis length in coherently grown films, vital for developing high-electron-mobility transistors and other devices based on β-(In _x Ga_1-x )₂O₃. Analytical techniques, including X-ray diffraction (XRD), reciprocal space mapping, and atomic force microscopy, were employed to evaluate crystal structure, strain relaxation, and surface morphology. The study identified a linear relationship between In composition and b-axis length in coherently grown films, facilitating accurate composition determination from XRD peak positions. The films demonstrated high surface flatness with root-mean-square roughness below 0.6 nm, though minor relaxation and granular features emerged at higher In compositions (x = 0.083) at the growth temperature of 750°C. XRD results revealed that lattice relaxation were observed at a growth temperature of 700°C despite low In composition. In contrast, at 800°C, the In composition was higher than at 750°C, and coherent growth was achieved. The surface morphology was the flattest at 750°C. These findings indicate that the growth temperature plays a crucial role in the mist CVD growth of β-(In _x Ga_1-x )₂O₃ thin films. This study offers insights into the relationship between In composition and lattice parameters in coherently grown β-(In _x Ga_1-x )₂O₃ films, as well as the effect of growth conditions, contributing to the advancement of ultra-wide bandgap semiconductor device development.

Discoveries and technological innovations over the past decade are transforming our understanding of the properties of ceramics, such as 'hard', 'brittle', and 'homogeneous'. For example, inorganic crystals containing molecular anions exhibit excellent secondary battery characteristics, and the fusion of inorganic solids and molecules results in innovative catalytic functions and physical properties. Different from the conventional ceramics such as metal oxides that are formed by monatomic cations and anions, unique properties and functions can be expected in molecular-incorporated inorganic solids, due to the asymmetric and dynamic properties brought about by the constituent molecular units. We name the molecular-incorporated inorganic materials that produce innovative properties and functions as supra-ceramics. In this article, we describe various kinds of supra-ceramics from the viewpoint of synthesis, analysis and physical properties/functions for a wide range of applications.

Two-dimensional (2D) magnetic materials with high critical temperatures (T _C ) and robust magnetic anisotropy energies (MAE) hold significant potential for spintronic applications. However, most of 2D magnetic materials are derived from the van der Waals (vdW) layered bulks, which greatly limits the synthesis of 2D magnetic materials. Here, 2D M₃B₄ (M = Cr, Mn, and Fe; B = Boron), derived from hexagonal and orthorhombic M₃AlB₄ phases by selectively etching Al layers, was studied for its structural stability, electronic structure, and magnetic properties. By utilizing ab initio calculations and Monte Carlo simulations, we found that the orthorhombic Cr₃B₄ shows ferromagnetic (FM) metal and possesses an in-plane magnetic easy axis, while the remaining hexagonal and orthorhombic M₃B₄ structures exhibit antiferromagnetic (AFM) metals with a magnetic easy axis which is perpendicular to the two-dimensional plane. The critical temperatures of these 2D M₃B₄ structures are found to be above the 130 K. Notably, the ort-Mn₃B₄ possesses highest T _C (~600 K) and strongest MAE (~220 µeV/atom) among these borides-based 2D magnetic materials. Our findings reveal that the 2D M₃B₄ compounds exhibit much better resistance to deformation compared to M₂B₂ MBenes and other 2D magnetic materials. The combination of high critical temperature, robust MAE, and excellent mechanical properties makes 2D Mn₃B₄ monolayer exhibits a favorable potential for spintronic applications. Our research also sheds light on the magnetic coupling mechanism of 2D M₃B₄, providing valuable insights into its fundamental characteristics.

Topological materials attract a considerable research interest because of their characteristic band structure giving rise to various new phenomena in quantum physics. Besides this, they are tempting from a functional materials point of view: Topological materials bear potential for an enhanced thermoelectric efficiency because they possess the required ingredients, such as intermediate carrier concentrations, large mobilities, heavy elements etc. Against this background, this work reports an enhanced thermoelectric performance of the topological Dirac semimetal Cd₃As₂ upon alloying the trivial semiconductor Zn₃As₂. This allows to gain fine-tuned control over both the band filling and the band topology in Cd_3-x Zn _x As₂. As a result, the thermoelectric figure of merit exceeds 0.5 around $x=0.6$ and $x=1.2$ at elevated temperatures. The former is due to an enhancement of the power factor, while the latter is a consequence of a strong suppression of the thermal conductivity. In addition, in terms of first-principle band structure calculations, the thermopower in this system is theoretically evaluated, which suggests that the topological aspects of the band structure change when traversing $x=1.2$ .

[This corrects the article DOI: 10.1080/14686996.2024.2378684.].

A sealant has been developed that improves upon current catheter-based treatments in the following ways: 1) Efficient delivery system, 2) No in situ polymerization, 3) No harmful byproducts, and 4) Cost-effective formulation. During the development process, particular attention was given to materials that were tunable, safe, and effective sealant agents. The thermo-responsive properties of poly(N-isopropylacrylamide) (PNIPAM) provides an ideal foundation to develop an optimized solution. Through a combination of model-based and material testing, a hydrogel was developed that balances conformational factors to achieve a customized transition temperature, radiopacity suitable for visualization, mechanical properties suitable for delivery via 3Fr catheter, sufficient cohesion once applied to resist migration under physiological pressures and an improved safety profile. Two applications, embolization of lymphatic leakage and exclusions of the left atrial appendage (LAA), to eliminate LAA dead space to reduce the risk of thromboembolic events, were considered. The material and benchtop results for this product demonstrate the suitability of this new material not only for these applications but also for other potential healthcare applications.

For olfactory sensors, clear differentiation of complex odour samples requires diverse information. To obtain such information, hardware modifications, such as introducing additional channels with different physical/chemical properties, are usually needed. In this study, we present a new approach to augmenting the sensing signals of an olfactory sensor by modulating the flow rate of the carrier gas. The headspace vapour of complex odours is measured using a sensing system of nanomechanical sensor (Membrane-type Surface stress Sensor, MSS). The resulting data set is quantitatively evaluated using the Davies-Bouldin index (DBI) of principal component analysis (PCA). The increasing number of sensing signals obtained at different gas flow rates leads to a decrease in the DBI, achieving better cluster separation between different odours. Such gas flow effects can be attributed to several factors, including the sample evaporation and the equilibrium of the gas-liquid and gas-solid interfaces. Proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOF-MS) experiments reveal that the compositions of odour samples vary with the different gas flow rates. It is demonstrated that a simple technique for modulating gas flow rates can significantly improve the differentiation performance of complex odours, providing an additional degree of freedom in olfactory sensing.