Rare Metals最新文献

The electrochemical reaction rate strongly depends on the pH of the solution and the relatively sluggish alkaline hydrogen evolution reaction (HER) process, attributed to alterations in the type of proton donor and binding energy, has consistently presented a significant challenge. Here, we report a new method for boosting alkaline HER via spontaneous built-in electric field strategy employed on cobalt phosphide nanofibers (NFs) electrocatalyst. The anion–cation dual-introduction of V and N on the NFs not only increases the electrochemical surface area but also enhances the catalytic activity, thereby elevating the performance of alkaline HER. An investigation strategy combining experiments and calculations revealed the charge transfer law between multiple active components and the enhanced regulation mechanism of alkaline HER process, ultimately achieving a nearly twice increase in reaction overpotential of the as-fabricated catalyst at − 10 mA·cm⁻². This new approach provides a potential strategy for improving the efficiency of core catalyst for energy conversion technologies.

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This study analyzed the prevalent physicochemical phases of smelting slag from the perspective of data science and chemistry. Findings delineated the silicate phase as the pivotal and predominant constraining phase for the resource utilization of smelting slag. An intricate correlation between metallic elements and dominant phases was constructed. Typical silicate phase olivine (OL) was synthesized as a paradigm to examine alkali depolymerization, unveiling the optimal conditions for such depolymerization to be an alkali to olivine molar ratio of 1:5, a reaction temperature of 700 °C, and a duration of 3 h. The underlying mechanism of alkali depolymerization within silicate phases was elucidated under these parameters. The reaction mechanism of alkali depolymerization within silicate phases can be encapsulated in three sequential steps: (1) NaOH dissociation and subsequent adsorption of OH⁻ to cationic (Mg or Fe) sites; (2) disruption of cation-oxygen bonds, leading to the formation of hydroxide compounds, which then underwent oxidation; (3) Na⁺ occupied the resultant cation vacancy sites, instigating further depolymerization of the intermediate Na₂(Mg,Fe)SiO₄. The articulated mechanism is anticipated to furnish theoretical underpinnings for the efficacious recuperation of metals from smelting slags.

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Flexible thermoelectrics provide a distinct solution for developing sustainable and portable power supplies. Inorganic/organic material compositing is an effective strategy to induce a significant enhancement of thermoelectric (TE) performance. However, the poor electrical performance of inorganic/organic material is attributed to the poor carrier transport between organic/inorganic interfaces induced by the low contribution of composited inorganic materials. Herein, we prepared a high room temperature figure-of-merit (ZT) value of ~ 0.19 and high bending resistance (surviving 1200 bending cycles at the bending radius of 16.5 mm) of p-type poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS)/Bi_0.5Sb_1.5Te₃ free-standing composite film via a facile vacuum-assisted filtration approach. Compositing Bi_0.5Sb_1.5Te₃ nano-spherical particles into PEDOT:PSS results in the optimized interfacial contact and carrier concentration, leading to a high Seebeck coefficient of ~ 43.79 μV·K⁻¹. Accordingly, a high-power factor of ~ 1.52 μW·cm⁻¹·K⁻² is achieved in the PEDOT:PSS/Bi_0.5Sb_1.5Te₃ composite film at room temperature. In addition, the PEDOT:PSS/Bi_0.5Sb_1.5Te₃ interfaces with phase boundaries, nanograins and point defects could further decrease the thermal conductivity to ~ 0.20 W·m⁻¹·K⁻¹, leading to a high ZT value. Furthermore, a 6-leg free-standing film device was assembled, which provided an output power of 44.94 nW. This study demonstrates that free-standing organic/inorganic composite films are effective power sources for wearable electronic products.

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Photocatalytic conversion of solar light into chemical fuels represents an appealing pathway by which a sustainable energy future might be realized. However, great scientific challenges need to be addressed for developing this technology, such as finding a way to acquire highly efficient semiconductor photocatalytic materials. Recently, halide perovskites have emerged as a novel class of semiconductors that display several exceptional advantages, including a large absorption coefficient, high carrier mobility, as well as customizable tunability of band gap, composition, structures, and morphologies. The development of photocatalysts solely based on pure halide perovskites encounters significant hurdles due to their intrinsically low stability and activity. A promising strategy to overcome this problem involves the construction of perovskite-based heterostructures. The integration with other components can enhance light absorption capacity, promote the separation of photogenerated carriers, and augment the number of surface reactive sites. In this review, we briefly summarize recent advances in the construction of perovskite-based photocatalytic heterostructures, where the perovskites serve either as the matrix or as a decoration material. Furthermore, the research accomplishments in employing these heterostructures for photocatalytic CO₂ reduction are reviewed. Finally, the major obstacles and the great potential for future design of perovskite-based heterostructures toward the creation of competitive CO₂ conversion photocatalysts are proposed.

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Metal-organic frameworks (MOFs) are highly desirable for promising photocatalytic water splitting, but their practical application is greatly limited due to their unstable chemical properties and insufficient visible light response as well as low charge-carries utilization, especially in photocatalytic O₂ production. Herein, we present a post-modification engineering to modulate cerium metal-organic frameworks (Ce-MOFs) for realizing efficient photocatalytic water oxidation to liberate O₂ by visible light. The one-step partial oxidation strategy is adopted to modify pristine Ce-MOFs, yielding the new Ce-MOFs (MV-Ce-MOFs) with mixed valence of Ce³⁺/Ce⁴⁺. Creating the Ce nodes of a mixed valence state can effectively extend the optical absorption to the visible region, expose more catalytically active sites and inhibit the recombination of photoinduced charges. Consequently, the MV-Ce-MOFs exhibit high activity for photocatalytic O₂ evolution under visible light, manifesting an impressive 1.6% apparent quantum efficiency (AQY) under monochromatic irradiation of 405 nm. The regulation engineering of MOF metal node valence heralds a new paradigm for designing MOF-based photocatalysts.

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The emergence of all-inorganic perovskite CsPbBr₃ has ignited significant interest in optoelectronic devices, However, CsPbBr₃ thin film-based photodetectors face performance limitations due to grain boundaries and defect density. To address these challenges, we introduce a novel type II heterojunction photodetector utilizing CsPbBr₃ microwires (MWs) and CdS nanoribbons (NBs). Remarkably, this photodetector exhibits exceptional characteristics: a high on/off current ratio (1.07 × 10⁵), a responsivity of up to 1.35 × 10⁴ A·W⁻¹, specific detectivity of 5.94 × 10¹⁵ Jones, external quantum efficiency of 2.83 × 10⁴% and rapid response/recovery time (400 μs/3 ms). These superior performances stem from the exceptional crystalline quality of CsPbBr₃ MWs and CdS NBs, coupled with the establishment of a type II band alignment at their interface. This configuration enables efficient carrier separation while suppressing recombination. Importantly, 1D CsPbBr₃ MW/CdS NB heterojunction photodetectors demonstrate reliable imaging capabilities under visible light illumination. Our findings present an innovative solution for high-performance perovskite-based photodetectors, holding promise for future commercial applications.

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Solid-state batteries with solid polymer electrolytes are considered the most promising due to their high energy density and safety advantages. However, their development is hindered by the limitations of polymer electrolytes, such as low ionic conductivity, poor mechanical strength and inadequate fire resistance. This study presents a thin polyvinylidene fluoride-based composite solid electrolyte film (25 μm) incorporating two-dimensional modified lipophilic lithium magnesium silicate (LLS) as additives with good dispersibility. The incorporation of LLS promotes grain refinement in polyvinylidene fluoride (PVDF), enhances the densification of electrolyte films, increases the tensile strength to 10.42 MPa and the elongation to 251.58%, improves ion transport interface, and facilitates uniform deposition of lithium ions. Furthermore, LLS demonstrates strong adsorption ability, promoting the formation of solvated molecules, resulting in high ionic conductivity (2.07 × 10⁻⁴ S·cm⁻¹ at 30 °C) and a stable lithium/electrolyte interface. Symmetric Li//Li cells assembled with the thin composite electrolytes exhibit stable cycling for 2000 h at 0.1 mA·cm⁻² and 0.05 mAh·cm⁻². Additionally, the LiFePO₄//Li battery shows a capacity retention rate of 99.9% after 200 cycles at 0.5C and room temperature.

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Remarkable developments in image recognition technology trigger demands for more advanced imaging devices. In recent years, traditional image sensors, as the go-to imaging devices, have made substantial progress in their optoelectronic characteristics and functionality. Moreover, a new breed of imaging device with information processing capability, known as neuromorphic vision sensors, is developed by mimicking biological vision. In this review, we delve into the recent progress of imaging devices, specifically image sensors and neuromorphic vision sensors. This review starts by introducing their core components, namely photodetectors and photonic synapses, while placing a strong emphasis on device structures, working mechanisms and key performance parameters. Then it proceeds to summarize the noteworthy achievements in both image sensors and neuromorphic vision sensors, including advancements in large-scale and high-resolution imaging, filter-free multispectral recognition, polarization sensitivity, flexibility, hemispherical designs, and self-power supply of image sensors, as well as in neuromorphic imaging and data processing, environmental adaptation, and ultra-low power consumption of neuromorphic vision sensors. Finally, the challenges and prospects that lie ahead in the ongoing development of imaging devices are addressed.

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N-doped carbon (NC) materials have emerged as attractive supports for metal-based catalysts, enhancing their catalytic performance through the metal–support interactions. However, gaining fundamental insights into the metal–support interaction between NC support and Sn metal sites for improving the electrocatalytic CO₂ reduction reaction (CO₂RR) performance remains challenging. Here, we reveal that pyridinic N in NC support indirectly induces the net electron distribution of Sn sites to exhibit optimal adsorption of HCOO* and HCOOH* by combining theoretical simulations and experiments, while pyrrolic N and graphitic N present weaker adsorption of HCOO* and stronger adsorption of HCOOH*, respectively. Consequently, the catalyst comprising NC with abundant pyridinic N loaded SnO₂ quantum dots exhibits excellent CO₂RR performance, achieving high partial formate activity (over 90 mA. cm⁻² in an H-cell and 200 mA. cm⁻² in a flow cell) and impressive Faradaic efficiency for formate (approximately 90%). This work provides valuable insights into intricate metal–support interactions, thereby offering guidance for the future design and development of CO₂RR electrocatalysts.

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摘要

高效且稳定的阴极材料缺乏阻碍了质子传导型固体氧化物燃料电池 (H-SOFCs) 的广泛应用。Sm₂Ba_1.33Ce_0.67Cu₃O₉(SBCC) 是一种由[CuO₅层][类CeO₂层][CuO₅层][Sm_xBa_1-xCuO_y钙钛矿层]交叉堆叠形成的层状材料。由于融合了不同的结构、化学和电子特性, 这种复合结构可以提高电催化性能。在此, SBCC阴极在H-SOFC中表现出优异的电池性能, 700 °C时的功率输出为1291 mW·cm⁻², 优于文献报道的其他Co基和Cu基单相阴极。此外, 通过在SBCC中用Nd替代Sm, 还获得了一种新型阴极材料Nd₂Ba_1.33Ce_0.67Cu₃O₉(NBCC) 。NBCC阴极基单电池性能优越, 在700 °C时的功率输出为1385 mW·cm⁻², 这归功于NBCC中更多的氧空位有利于氧还原反应。NBCC和SBCC优异的电化学性能和良好的运行稳定性表明, 交叉叠层结构材料是一种很有前途的H-SOFC阴极材料。这项研究为开发高活性、耐用的H-SOFC阴极提供了一条新途径。

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