Rare Metals最新文献

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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Monochloroacetic acid (MCAA) is identified as a highly carcinogenic disinfection by-product in chlorinated drinking water. In this study, a series of CeO₂-supported Pd catalysts (Pd/MCeO₂) were synthesized through one-step calcination of Pd-loaded Ce-UiO-66-BDC (Ce-MOF), and the liquid-phase catalytic hydrodechlorination of MCAA was explored using these catalysts. For comparison, Pd/CeO₂ catalysts were additionally synthesized using the conventional impregnation method. The characterization results reveal that the catalysts exhibit strong metal–support interaction, leading to high Pd dispersion and Pdⁿ⁺ content. Additionally, the calcination temperature significantly influences catalytic performance, with the catalyst calcined at 500 °C (Pd/MCeO₂-500) demonstrating the highest catalytic activity and achieving complete dechlorination of MCAA within 50 min. Furthermore, it is found that the catalytic MCAA hydrodechlorination using the catalysts adheres to the Langmuir–Hinshelwood model. Accordingly, low reaction pH is favorable for the catalytic hydrodechlorination of MCAA, enhancing MCAA adsorption on the catalyst surface due to the electrostatic interaction between MCAA and the catalyst surface. Theoretical results suggest that the presence of Pdⁿ⁺ efficiently facilitates MCAA adsorption and C–Cl cleavage, thus significantly enhancing the liquid-phase catalytic hydrodechlorination.

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The aqueous ammonium ion (NH₄⁺) is a promising charge carrier in virtue of its safety, environmental friendliness, abundant resources and small hydrated ionic size. The exploration of NH₄⁺ host electrodes with good reversibility and large storage capacity to construct high-performance ammonium-ion hybrid capacitors (AIHCs), however, is still in its infancy. Herein, a facile etching technique is put forward to produce oxygen-deficient MnO₂ (O_d-MnO₂) as the electrode material for NH₄⁺ storage. According to the experimental and theoretical calculation results, the etching process not only creates more porosity, offering abundant active sites, but also generates abundant oxygen vacancies, which modify the structure of pristine MnO₂, enhance charge storage capacity and boost ion diffusion kinetics. Consequently, O_d-MnO₂ can deliver a specific capacity of 155 mAh·g⁻¹ at 0.5 A·g⁻¹ and a good long-term cycling stability with 86.8% capacity maintained after 10,000 cycles at 5.0 A·g⁻¹. Additionally, the NH₄⁺ storage mechanism was evidenced by several ex-situ characterization analyses. To examine the actual implementation of O_d-MnO₂ as a positive electrode for NH₄⁺ full device, AIHCs are assembled with activated carbon functionalized with Fe₃O₄ nanoparticles (Fe₃O₄@AC) as a negative electrode. A high specific capacitance of 184 F·g⁻¹ at 0.5 A·g⁻¹, satisfactory energy density of 102 Wh·kg⁻¹ at 500 W·kg⁻¹, a low self-discharge rate and good cycling durability after 10,000 cycles are attained. The electrochemical performance of these AIHCs is comparable to or surpass those of traditional supercapacitors with metal ions as charge carriers, highlighting the advantages of structural modification in enhancing the NH₄⁺ storage performance.

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Photothermal conversion is one of the key technologies in solar energy collection, seawater desalination, photothermal treatment and other important fields. In order to develop next generation photothermal materials, four polyoxometalates, [(CH₃)₂NH₂]₁₂H₅[Ni₃Mo₁₈O₅₄(HPO₃)₁₀(PO₄)]·18H₂O (Compound 1), [(CH₃)₂NH₂]₁Na₁₁[Ni₂Mo₈O₂₂(HPO₃)₁₀]·16H₂O (Compound 2), Na₁₅(OH)₅[Mo₆O₁₈(HPO₃)₄]₂[MoO]_1.5·16H₂O (Compound 3), [(CH₃)₂NH₂]₄Na₁₁[Na[Mo₆O₁₅(HPO₃)₄]₂]·18H₂O (Compound 4), are successfully designed and synthesized via a microwave-assisted reaction protocol. Compounds 1–4 not only exhibit broad absorption and notable photothermal conversion effects in near-infrared (NIR) region, but also have high photothermal conversion efficiencies and high quality NIR photothermal imaging effects under NIR laser irradiation. Compound 1 shows the best photothermal conversion effect, and it provides a unique model to explore the relationship between the complex metal oxide structure and photothermal conversion behavior at the molecular level. Both the experimental results and theoretical calculations consistently conclude that the charge and degree of electron delocalization on the Cluster have a robust influence on the photothermal conversion, as well as the aggregation microstructures.

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With the swift advancement of renewable energy and escalating demands for energy storage, potassium-ion batteries (PIBs) are increasingly recognized as a potent energy storage technology. Various carbon anode materials have been utilized for PIBs anodes owing to their superior K⁺ storage capacity, outstanding cycling performance, elevated capacity, and cost-effectiveness. Therefore, it is imperative to explore and improve carbon anode materials. This review meticulously encapsulates the recent scholarly advancements in carbon anode materials for PIBs. It elucidates the operational mechanisms of carbon anode for PIBs, provides a synopsis of diverse carbon materials, and deliberates on the prevalent challenges, including cycling stability and potassium-ion diffusion rates. Although soft and hard carbon augmented potassium-ion capacities, the expansive surface areas coupled with the large ionic radius of K⁺ pose substantial challenges to their structural design and optimization. Consequently, this review outlines strategic approaches to the design of carbon materials for excellent potassium storage performance, including the expansion of interlayer spacing, modification of morphology, heteroatom doping, structural defect regulation, incorporation of porous structures, and development of carbon–carbon composites. Finally, the challenges and prospective solutions of carbon anode materials for PIBs with superior energy density and cycling stability were proposed, providing a reasonable guidance for regulation design of carbon materials.

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Single-atom catalysts (SACs) have been widely utilized in electrochemical nitrogen reduction reactions (NRR) due to their high atomic utilization and selectivity. Owing to the unique sp/sp² co-hybridization, graphyne materials can offer stable adsorption sites for single metal atoms. To investigate the influence of the sp/sp² hybrid carbon ratio on the electrocatalytic NRR performance of graphyne, a high-throughput screening of 81 catalysts, with 27 transition metals loaded on graphyne (GY1), graphdiyne (GY2), and graphtriyne (GY3), was conducted using first-principles calculations. The results of the screening revealed that Ti@GY3 exhibits the lowest energy barrier for the rate-determining step (0.32 eV) in NRR. Further, to explore the impact of different sp/sp²-hybridized carbon ratios on the catalytic activity of SACs, the mechanism of nitrogen (N₂) adsorption, activation, and the comprehensive pathway of NRR on Ti@GY1, Ti@GY2, and Ti@GY3 was systematically investigated. It was found that the ratio of sp/sp²-hybridized carbon can significantly modulate the d-band center of the metal, thus affecting the energy barrier of the rate-determining step in NRR, decreasing from Ti@GY1 (0.59 eV) to Ti@GY2 (0.49 eV), and further to Ti@GY3 (0.32 eV). Additionally, the Hall conductance was found to increase with the bias voltage in the range of 0.4–1 V, as calculated by Nanodcal software, demonstrating an improvement in the conductivity of the SAC. In summary, this work provides theoretical guidance for modulating the electrocatalytic nitrogen reduction activity of SACs by varying the ratio of sp/sp² hybrid carbon, with Ti@GY3 showing potential as an excellent NRR catalyst.

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