Rare Metals最新文献

Rare earth elements (REEs), with their unique magnetic, optical, and electrical properties, have become indispensable strategic resources. Widely applied in critical fields such as aviation, telecommunications, electronics, energy, transportation, and medicine, REEs play a vital role in advancing technology and driving social and economic development. However, the REE industry faces numerous challenges, including unbalanced resource distribution, supply and demand imbalances, international competition, technological limitations, and associated environmental pollution. This paper, incorporating both the historical evolution and current state of the REE industry, provides a comprehensive examination of the chemistry, applications, resources, technologies, challenges, and prospects of REEs. Specifically, it analyzes China’s REE industry, which holds the largest global reserves and production capacity. As a key feature, this paper introduces the Tai Chi model for sustainable development in the REE industry, offering an in-depth analysis of two primary approaches—mining and recycling; the four critical participants—governments, enterprises, researchers, and consumers; and the eight essential influencing factors—resources, energy, environment, policy, applications, technology, supply and demand, and economy. The Tai Chi model not only clarifies the responsibilities and significance of each individual but also highlights their interconnectedness, providing a compelling framework for envisioning the sustainable development of the REE industry. Moreover, the paper identifies the major challenges currently facing the industry and offers insights into the future development of REEs. As such, this work contributes to a deeper understanding of the multifaceted REE landscape and underscores the importance of sustainable practices to ensure REEs’ lasting positive impact on the global industry.

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To effectively enhance the catalytic activity of NiS, NiS particles confined into carbon fibers were prepared by electrostatic spinning followed pyrolyzation and NiS particles decorating was performed by further hydrothermal loading. The decorated NiS exhibits particle (NiS@PAN-NiS) and needle-like (NiS@PAN-NiS*) morphologies. After adding the catalysts into MgH₂, the synthesized MgH₂-5 wt% NiS@PAN-NiS composite can absorb 2.6 wt% hydrogen at 353 K and release 5.0 wt% hydrogen within 1 h at 573 K. The initial hydrogen desorption temperature was reduced to 539 K. The activation energies for hydrogen absorption/desorption were greatly reduced to 66.76 and 89.95 kJ mol⁻¹, respectively. The method of confining by electrospinning and particle decoration by hydrothermal loading reduce NiS particle agglomeration. The Mg₂Ni/Mg₂NiH₄ hydrogen pump formed by reaction between NiS and MgH₂ effectively enhanced hydrogen absorption and desorption kinetics. The formed MgS also improved the catalytic activity on the transformation of Mg and MgH₂. Moreover, the carbon fibers should influence the contact between in situ formed MgS and Mg₂Ni, providing more catalytic sites and hydrogen diffusion pathways. The construction of NiS/carbon fibers confined NiS composite by carbon fibers derived from pyrolyzation as medium provides considerable way for designing NiS-based catalysts to enhance the hydrogen storage performances of MgH₂.

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Layered transition metal dichalcogenides (TMDs) have emerged as promising electrode materials for supercapacitors due to their high theoretical specific capacitance, unique layered structure, large surface area, and tunable energy band structure. Substantial progress has been made in the development of TMDs for supercapacitors, with several great breakthroughs reported. However, the practical application of TMDs is still hindered by several challenges, including their susceptibility to oxidation, the tendency to restack or aggregate, structural instability, and interior electrical conductivity. To overcome these limitations, the construction of heterostructures has been identified as an effective strategy. By modulating the interface structure between different components, heterostructures can enhance overall structural stability and facilitate faster ion transport, thereby improving the efficiency of supercapacitors. This review provides a comprehensive overview of recent advances in TMD-based heterostructures for supercapacitors, focusing on their synthesis methods, the relationship between structure, properties, and electrochemical performance, as well as existing challenges. Particular emphasis is placed on heterostructure engineering strategies that integrate TMDs with materials of various dimensionalities (0D, 1D, 2D, and 3D) to enhance their electrochemical performance for supercapacitors. Finally, the review discusses critical challenges and outlines future perspectives that may guide the development of TMDs for supercapacitors and beyond.

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Lead-free halide double perovskite-based white light-emitting diodes (WLEDs) have recently emerged as promising candidates for advanced lighting technologies. However, their inherent characteristics, such as indirect bandgaps and forbidden electronic transitions, significantly limit photoluminescence (PL) efficiency, posing critical challenges to their widespread application. Herein, we selected highly efficient blue-emitting Cs₂NaInCl₆:Bi³⁺ nanocrystals (NCs) as a matrix, into which lanthanide ions (Ln³⁺) were incorporated by ion doping, yielding a series of Ln³⁺-doped perovskite NCs, Cs₂NaInCl₆:Bi³⁺,Ln³⁺(Ln³⁺ = Eu³⁺, Tb³⁺ and Dy³⁺), with an impressive photoluminescence quantum yield (PLQY) of 85.1%. Doping with Ln³⁺ effectively regulates the optical bandgap and PL efficiency of these materials. Femtosecond transient absorption (fs-TA) spectroscopy reveals changes in self-trapped exciton (STE) dynamics and reduced deep trap-related states upon Ln³⁺ doping, indicating effective modulation of self-trapping and defect passivation. The lead-free halide double perovskite-based WLED devices were demonstrated by coating the highly fluorescent green-emissive Cs₂NaInCl₆:Bi³⁺,Tb³⁺ NCs with red-emitting (Sr, Ca)AlSiN₃:Eu phosphor on a commercial ultraviolet (UV) chip, achieving a color-rendering index (CRI) of 87.5 and a correlated color temperature (CCT) of 5723 K. This study is laying a theoretical foundation for the regulation of the optical properties of lead-free halide double-perovskite NCs and defining an ideal model for the development of efficient WLEDs.

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We developed a family of Ln³⁺-Bi³⁺ co-doped NCs, Cs₂NaInCl₆:Bi³⁺,Ln³⁺ (Ln³⁺  = Eu³⁺, Tb³⁺, Dy³⁺), with multicolor luminescence and excellent stability. The luminescence mechanism revealed energy transfer from Bi³⁺ to Ln³⁺ and achieved efficient self-trapping excitation emission of these materials. WLED device was fabricated using green emissive Cs₂NaInCl₆:Bi³⁺,Tb³⁺ NCs (PLQY = 85.1%) with excellent optical stability.

Aqueous zinc-ion batteries (AZIBs) have garnered significant attention owing to their intrinsic safety and the abundance of zinc resources. Traditional separators, such as glass fiber (GF), face challenges such as zinc dendrite penetration, inadequate mechanical strength, and excessive thickness, which results in increased internal resistance and diminished battery performance. In this study, we investigate the use of a mixed cellulose ester (MCE) filter membrane as a separator for AZIBs. The 110-μm-thick MCE separator exhibits a mechanical strength of 4.88 MPa, which is 12 times greater than that of the 325-μm-thick GF separator, and effectively resists zinc dendrite formation, even with a thinner design. Zn symmetric batteries utilizing the MCE separator exhibit a cycle time of 2700 h at 1 mA cm⁻². The MCE separator, incorporating hydroxyl and nitrogen functional groups, promotes uniform zinc deposition and mitigates the formation of by-products on the zinc anode, thereby enhancing corrosion resistance. Zn||MnO₂ full batteries with the MCE separator demonstrate a specific capacity of 161 mAh g⁻¹ at 1 A g⁻¹, with a capacity retention of 80.1% after 500 cycles. Furthermore, Zn||VO₂ full cells employing the MCE separator exhibit excellent rate performance and cycling stability. At 0.25 A g⁻¹, the Zn||VO₂ cell retains 86.9% of its capacity after 800 cycles, demonstrating a high capacity of 243 mAh g⁻¹. This study offers novel insights into enhancing the performance of AZIBs through the selection of a low-cost, high-strength, and thin separator design.

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The growing demand for low-expansion alloys in high-tech industries such as aerospace, electronics, communications, and healthcare underscores the necessity of enhancing their performance under extreme operating conditions. This review explores the influence of alloy composition and processing techniques on the key properties of low-expansion alloys, including strength, operating temperature range, magnetic properties, corrosion resistance, and thermal conductivity. The role of microalloying and the optimization of processing parameters in improving these properties are discussed, with an emphasis on the underlying mechanisms and the intricate relationships between composition, processing, and properties. Future breakthroughs in studying low-expansion alloys are anticipated through the use of multi-functional databases, high-throughput experiments or calculations, and machine learning for multi-objective optimization. This work provides insightful perspectives and practical guidance for advancing low-expansion alloys in both academic research and industrial applications.

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Aqueous zinc-based batteries (ZBBs) are promising for grid-scale energy storage owing to their safety and cost-effectiveness; however, their practical application is hindered by rapid capacity fading and unstable cathodes caused by sluggish Zn²⁺ kinetics and structural degradation in alkaline electrolytes. Herein, to address these challenges, we utilize amphiphilic polymer (PVP) to realize the composite of nickel-based complexes and ZIF-67. The hierarchical nickel–cobalt layered double hydroxide (NiCo-LDH) was prepared by metal ion exchange strategy. PVP-mediated-mediated suppression of agglomeration, combined with Ni²⁺-induced framework reconstruction, synergistically modulated the morphology, resulting in mesoporous nanosheets with hydroxyl-rich surfaces. This design generated high-valence Co³⁺ species through charge-compensation-driven oxidation, thereby significantly accelerating Zn²⁺ ion diffusion and reducing the interfacial resistance. The optimized NiCo-LDH-100 cathode (Ni:Co = 3:1) achieves cycling stability and exceptional energy/power densities (0.49 mWh cm^–2/49.1 mW cm^–2). This study provides a solution for the cathode instability of Ni-Zn batteries through a coordination-derivatization strategy, which is promising for advancing sustainable energy storage technologies.

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Zinc (Zn) alloys exhibit substantial potential for application in the domain of metal materials that are both biodegradable and implantable because of their appropriate degradation rate and biocompatibility. Selenium (Se) has been widely employed in tumor treatment, positioning Zn-Se alloys as promising candidates for the development of the next generation of antitumor degradable materials. However, the considerable disparity in melting points and the volatility of elemental Zn and Se pose significant challenges for alloying using conventional melting methods. Here, we report a Zn–4Ag–2Se alloy using silver selenide (Ag₂Se) as the Se source for biodegradable implant materials. The alloy’s antibacterial and antitumor capabilities, along with its mechanical, corrosion, and biocompatibility properties, were assessed and then compared to the properties of a Zn-4Ag alloy. Both alloys consisted primarily of η-Zn and ε-AgZn₃ phases, with the Zn–4Ag–2Se alloy additionally containing a minor amount of a ZnSe phase. The hot-rolled (HR) Zn–4Ag–2Se alloy exhibited an ultimate tensile strength of 211.5 ± 2.3 MPa and elongation of 24.9% ± 0.6%. Additionally, the HR Zn–4Ag–2Se alloy demonstrated an electrochemical corrosion rate of 105.51 ± 1.21 μm year⁻¹ and degradation rate of 59.8 ± 0.2 μm year⁻¹ in Hanks’ solution, meeting the performance criteria for degradable implant materials. The HR Zn–4Ag–2Se alloy also exhibited excellent antibacterial activity, evidenced by an inhibition zone diameter (IZD) of 2.22 ± 0.01 mm and colony-forming unit count of 58 ± 2. The HR Zn–4Ag–2Se alloy did not inhibit the proliferation of MC3T3-E1 cells but promoted reactive oxygen species production and finally cell death toward MG63 osteosarcoma cells.

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Photocatalytic CO₂ reduction using atomically dispersed catalysts holds significant potential for addressing global energy and environmental challenges. However, the influence of d–d orbital interactions between metal centers and coordinated atoms remains underexplored. Herein, nickel phthalocyanine is anchored to the metal-exposed crystal face of TiO₂, forming Ti–Ni–N₄ coordination. This configuration reveals that the axially coordinated Ti atoms serve as a novel electron channel with electron-donating ability, transferring electrons to the Ni center through d–d coupling. It is found that the dynamic adjustment of bond lengths and d-band centers in Ti–Ni bonding during CO₂ photoreduction process can effectively modulate the adsorption strengths of the Ni center for different intermediates. This leads to a significant enhancement in the photocatalytic performance for CO₂ reduction to CO without a sacrificial reagent, achieving an exceptional CO evolution rate of 378.5 μmol g⁻¹. Furthermore, the d–d coupling mediated by Ti–Ni–N₄ coordination increases the vacancy formation energy of active sites, preventing the leaching of Ni active centers. This study provides a strategy for the precise design of d–d orbital regulation and resistance to demetallization in photocatalysts for efficient CO₂ conversion.

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Severe structural fractures and persistent side reactions at the interface with liquid electrolytes have hindered the commercialization of silicon (Si) anodes. Solid-state electrolytes present a promising solution to address these issues. However, the high interfacial resistance of rigid ceramic electrolytes and the limited ionic conductivity of polymer electrolytes remain significant challenges, further complicated by the substantial volume expansion of Si. In this work, we chemically grafted a flame-retardant, self-healing polyurethane-thiourea polymer onto Li₇P₃S₁₁ (SHPUSB-40%LPS) via nucleophilic addition, creating an electrolyte with exceptional ionic conductivity, high elasticity, and strong compatibility with Si anodes. We observed that FSI⁻ was strongly adsorbed onto the LPS surface through electrostatic interactions with sulfur vacancies, enhancing Li⁺ transport. Furthermore, SHPUSB-40%LPS exhibits dynamic covalent disulfide bonds and hydrogen bonds, enabling self-assembly of the electrolyte at the interface. This dynamic bonding provides a self-healing mechanism that mitigates structural changes during Si expansion and contraction cycles. As a result, the Si anode with SHPUSB-40%LPS presents excellent cycling stability, retaining nearly 53.5% of its capacity after 300 cycles. The practical applicability of this design was validated in a 2 Ah all-solid-state Si||LiNi_0.6Mn_0.2Co_0.2O₂ pouch cell, which maintained a stable Li-ion storage capacity retention of 76.3% after 350 cycles at 0.5C. This novel solid-state electrolyte with self-healing properties offers a promising strategy to address fundamental interfacial and performance challenges associated with Si anodes.

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