Small Methods最新文献

Recently, Te_1-xSe_x films have shown significant potential for infrared detection. However, the conventional deposition process of Te_1-xSe_x films typically requires a cooled substrate, which results in the formation of poorly crystallized materials. Achieving controlled synthesis of large-area Te_1-xSe_x films remains a major challenge. Herein, two-inch Te_1-xSe_x films is successfully prepared using a low-pressure chemical vapor deposition technique based on a selenium phase transition-induced strategy. The chemical compositions of Te_1-xSe_x (x ranging from 0 to 1) films can be precisely controlled by adjusting the molar ratio of Te and Se powders. The phase change of amorphous Se at elevated temperatures generates additional dangling bonds on its surface, which facilitates the incorporation of Te atoms into Se chains forming Te_1-xSe_x alloys. COMSOL simulations reveal that maintaining uniform concentration and temperature during the growth process is essential for the formation of Te_1-xSe_x films. Importantly, the Te_0.4Se_0.6 film detector realizes high-performance near-infrared single-pixel imaging with a resolution of 128 × 128 pixels. This work has fabricated wafer-scale Te_1-xSe_x alloy thin films, which exhibit excellent properties, providing important experimental and theoretical support for exploring the applications in the fields of electronics, photonics, and optoelectronics.

The application of lithium-ion batteries challenges environmental sustainability and calls for efficient recycling toward circular economics. Hydrometallurgical recycling, despite being commercialized, still faces challenges such as harsh chemicals, high secondary waste generation, and low efficiencies. Intuitively, higher temperature leads to exponentially higher reaction kinetics (following Arrhenius's law), yet the dissolution temperature is limited to below 100 °C while heating the solution means more energy consumption. This study presents a laser-assisted wet leaching (Laser-WL) method that enables decoupled particle/solution temperatures, where the cathode particles are effectively heated by laser adsorption (30 W) to accelerate the dissolution kinetics (7-10 fold) while the solution remains cool for energy saving. Besides, physical laser ablation helps remove the robust solid electrolyte interface and cracks the particles to expose active materials, shortening the diffusion pathways and further enhancing the leaching kinetics. Therefore, Laser-WL can achieve an extraction rate of 95.6% in 15 min (traditional method >3 h). It reduced the consumption of concentrated HCl by 87%, and water consumption by 27%. The method is applicable to various cathode materials and works for weak acids, thus presenting a sustainable and economically viable solution for metal recycling.

Electrocatalytic water splitting for hydrogen generation plays a crucial role in promoting the energy transition and achieving the goals of carbon neutrality. Nevertheless, in the context of water electrolysis, the generated bubbles have an adverse impact on energy consumption and mass transfer efficiency. To address this challenge, a variety of strategies are investigated to accelerate bubble detachment and transport. It is of utmost significance to summarize those strategies for facilitating the advancement of water electrolysis performance. In this review, a comprehensive account of strategies are presented for enhancing water electrolysis performance through bubble behavior management. First, the impact of the electrolyte on bubbles is discussed. Then, optimized interactions between bubbles and the electrode surface are introduced, which focus on reducing adhesion forces and implementing other forces. Next, dynamic bubbling of deformable catalysts is discussed, such as fern- and caterpillar-like catalysts. Following that, bubble-bubble interactions are investigated as bubble coalescence is proved to be beneficial for earlier bubble departure compared to buoyancy effect alone. Finally, outlooks are presented for future development of efficient bubble removal strategies for enhanced water electrolysis performance. The review aims to deepen the comprehension of bubbles interactions and stimulate the development of management strategies, thereby further enhancing the performance of water electrolysis.

Nucleic acids, such as microRNA and circulating tumor DNA, are widely utilized potential biomarkers for early disease diagnosis. Electrochemical sensors with high sensitivity play a significant role in quantitative bioanalysis, however, target molecules during detection usually bind to probes and limit their reusability. Powered by DNA/RNA fuel and enzyme-based fuel consumption unit, dissipative DNA systems can perform periodic tasks in a self-resettable manner. Here, a self-resetting electrochemical sensor is reported for miRNA detection based on dissipative DNA networks. The target microRNA-21 (miRNA-21) invades the incumbent strand and activates the strand displacement process. Released ferrocene-modified strands bind to the probe on the electrode surface for accurate detection. The miRNA within RNA/DNA heteroduplex will then be digested by RNase H to free the incumbent strand which replaces the ferrocene strand and restores the probe to the initial state. It is found that the detection limit of this self-resetting electrochemical sensor is 0.35 pM for the third cycle. The self-resetting electrochemical sensor can not only achieve lower detection limits, and maintain repeatability and stability in complex matrices, but also reduce the detection cost of electrochemical sensors. It is envisioned that many real-life applications can be initiated such as analyzing various oligonucleotide biomarkers during early cancer diagnosis and bioanalysis.

NASICON-type Na₃V₂(PO₄)₃(NVP) material possesses robust 3D structure and high sodium diffusivity, thus showcasing its immense potential in sodium-ion batteries (SIBs). However, considering the perspective of environmental conservation, it is imperative to substitute vanadium with elements that are both cost-effective and non-toxic in order to further enhance its application in SIBs. Herein, Fe is utilized to replace the V site in the sodium vanadium phosphate structure and successfully prepared a pure phase sodium-deficient NASICON (sodium superionic conductor) Na_3.15VFe_0.86(PO₄)₃ (NVFP-650) cathode. It is found that the regulation of sintering temperature for Na_{3+ x}VFe(PO₄)₃(NVFP) material can effectively mitigate the formation of secondary phases and enhance the electrochemical properties of the resulting product. The sodium-deficient cathode shows enhanced electrochemical performance and sodium ion diffusion kinetics. It exhibits a high capacity of 102.8 mAh g^-1 at 0.1 C, and exhibits a high-capacity retention of 95.7% after 2000 cycles at 20 C. The energy storage mechanism and structural evolution are further investigated through SEM, TEM, XPS, and in situ XRD characterizations. The compositional modulation of sodium-deficient NVFP and the elucidation of its cycling mechanisms in this work would provide valuable insights for enhancing the performance of sodium energy storage systems.

Overuse of herbicides poses a serious threat to ecosystems and human health; thus, the accurate determination of herbicide residue is very meaningful. Thanks to the advantage of no background fluorescence interference, the upconversion luminescence allows for reliable analysis of target molecules in complicated samples. Here, through screening of 20 natural amino acids, it is discovered that the photooxidation of methionine exhibited the fastest recovery rate of triplet-triplet annihilation upconversion (TTA-UC) luminescence via oxygen consumption, which is 400-fold faster compared to the well-known photooxidation of oleic acid. Furthermore, oxygen-resistant, small-size, red-to-blue TTA-UC nanoparticles with a record upconversion efficiency (7.2%, normalized to 100%) are prepared using hydrophobic butyl methionine as an oxygen scavenger. Surface negatively charged TTA-UC nanoparticles are able to selectively enrich positively charged paraquat on their surface. Accordingly, a photoinduced electron transfer process occurred between the triplet excited state of the photosensitizer and the electron-deficient paraquat, quenching the upconversion luminescence. Relying on this principle, TTA-UC-based paraquat sensing is achieved with a fast response (less than 1 s), high selectivity, and a low limit of detection (1.54 µg mL^-1). Further, the TTA-UC nanoparticles are utilized to implement paraquat analysis in lake water without sample pretreatment.

Graphitic carbon nitride (C₃N₄) has been identified as an optimal material for hydrogen peroxide (H₂O₂) photosynthesis, although its utility is hampered by a high photocarrier recombination rate. Herein, a novel carbon nitride material with a giant built-in electric field (BEF), Trz-CN, is synthesized through a hydrothermal-calcination tandem strategy. The giant BEF (4.8-fold) induced by the large dipole moment facilitated the efficient separation and directional migration of photogenerated carriers. Trz-CN exhibited an H₂O₂ production rate of 569.9 µmol·g^-1·h^-1 using O₂ as feedstock under visible light (λ > 420 nm), marking an impressive 11.2-fold enhancement compared to bulk C₃N₄. Utilizing air instead of pure O₂ as feedstock resulted in a trivial 1.6% decrease in the H₂O₂ generation by Trz-CN while maintaining a substantial production rate of 560.6 µmol·g^-1·h^-1. Notably, Trz-CN showcased a sterilization rate of 99.9% against Escherichia coli (E. coli) in natural seawater. Density functional theory (DFT) calculations revealed that incorporating a nitrogen-rich skeleton into the C₃N₄ enhanced its oxygen adsorption capacity and lowered the energy barrier for H₂O₂ formation. This leads to enhanced photocatalytic performance for H₂O₂ generation under ambient air conditions. Trz-CN provides a new exploratory idea for direct air synthesis of H₂O₂ and ballast water treatment.

Atomically thick hexagonal boron nitride (h-BN) films have gained increasing interest, such as nanoelectronics and protection coatings. Chemical vapor deposition (CVD) has been proven to be an efficient method for synthesizing h-BN thin films, but its precursors are still limited. Here, it is reported that a novel and easily available precursor, surface-activated h-BN (As-hBN), with NH₃/N₂ as an additional nitrogen source is used for CVD growth of monolayer h-BN films on the Cu foils. The as-grown h-BN films can significantly enhance the anti-oxidation ability of copper. Molecular dynamics simulations reveal that the reactivity of the As-hBN precursors is attributed to the decomposition of unstable BO₃ and O-terminal edges on the surface under H₂ atmosphere. This method provides a more reliable approach for fabricating h-BN films.

The practical application of sodium metal batteries faces significant challenges, such as unpredictable Na dendrite growth and the instability of solid-electrolyte interphase. Herein, a novel separator composed of glass fiber (GF) impregnated with a zeolitic imidazolate framework (ZIF-8) layer, referred to as GF@ZIF-8 is introduced. This optimized separator exhibits enhanced anti-puncture strength, a high Na transference number, and fast Na-ion conductivity. The ZIF-8 layer effectually regulates the spatial concentration distribution of Na ions and their flux vectors, leading to the homogeneous deposition of Na. Consequently, the Na||Na symmetric cells utilizing the GF@ZIF-8 separator demonstrate outstanding cyclability, achieving 850 h at 0.5 mA cm^-2 and 420 h at 1 mA cm^-2, outperforming cells with bare GF (<180 h). Furthermore, the assembled Na₃V₂(PO₄)₃||GF@ZIF-8||Na full cells exhibit remarkably improves rate performance (81 mA h g^-1 at 30 C), cyclability (93.5% capacity retention over 900 cycles at 10 C), and low-temperature applicability (78 mA h g^-1 under 0.2 C and -40 °C). The simulations reveal that, except for regulating Na-ion flux, the introduction of the porous ZIF-8 on the GF separator also enhances the local electric field near the anode, thereby boosting the transfer of Na⁺, which contributes to the improved Na storage performance.

Wearable self-powering sensors based on triboelectric nanogenerators (TENGs) emerging as a promising strategy for a wide range of applications, such as self-powering and energy-harvesting systems, are widely used in healthcare and displacement current are utilized as the driving force. Although the TENG theory is rooted in the displacement current equation proposed by Maxwell, the magnetic field created by this current is often overlooked in TENG research. In this work, an effective charge-trapping method based on the magnetization current induced by transition metal ion chelation is reported. The experimental results, along with a theoretical analysis of the Maxwell equation and a discussion of the charge-trapping mechanism, demonstrate that magnetic materials provide enhanced charge-trapping performance. Transition metal ions chelated to mesoporous silica particles (MSPs) can slightly assign weak paramagnetic properties owing to the formation of ligand complexes. As a result, they can generate a feeble quasi-magnetization current during the TENG cycle, which enhances the surface charge density of the Co-MSPs-based polyvinyl alcohol TENG (PVA-TENG) by 68%. In addition, it is confirmed that the MSPs chelated with transition metal ions exhibit antibacterial properties, thereby providing promising synergistic effects from the perspective of application as a wearable TENG-based antibacterial sensor system.