Nano Research最新文献

Pristine tin (Sn) and tin dioxide (SnO₂) have sparked wide interest owing to their abundant resources and superior theoretical capacity. Nevertheless, the obvious volume expansion effect upon cycling and undesirable conductivity of Sn-based materials lead to undesirable specific capacity. In this work, a nanostructured Sn/SnO₂/nitrogen-doped carbon (NC) superstructure was prepared through a facile electrospray-carbonization strategy. The Sn/SnO₂ nanoparticles (NPs) were uniformly dispersed in a spherical NC matrix, which prevented the volume expansion and aggregation of NPs and facilitated the ion diffusion and charge transfer kinetics. When the optimized Sn/SnO₂/NC superstructures were employed as lithium-ion battery anodes, a remarkable specific capacity of 747.9 mAh·g⁻¹ over 200 cycles at 0.5 A·g⁻¹ and a superior cyclability of 644.1 mAh·g⁻¹ over 1000 cycles at 2 A·g⁻¹ were obtained. This effective synthetic strategy for synthesizing superstructures provides valuable insights for the advancement of lithium-ion batteries.

This review highlights the critical effects of heat transfer and bubble mass transfer in alkaline water electrolysis on hydrogen generation efficiency. To improve heat transfer performance, the study focuses on reducing electrical resistance and controlling the electrolysis system’s temperature. It proposes innovative strategies such as using metal matrix composites and catalysts to optimize electrode structure, precise temperature and pressure regulation and enhanced electrolyte concentration. Additionally, the study examines the dynamics of bubble mass transfer, proposing effective strategies to reduce bubble coverage, including hydrophilic electrodes, mechanically circulating the electrolyte and voltage smoothing with pressure swinging. This study contributes to the advancement of hydrogen energy technology with practical strategies. By adjusting the electrolysis system to optimize the combined effect of these factors, we can improve the efficiency, economy and environmental friendliness of hydrogen production. This will contribute to the transformation of the global energy mix and the implementation of sustainable development strategies.

Assembly of two-dimensional (2D) nanomaterials into well-organized architectures is pivotal for controlling their function and enhancing performance. As a promising class of 2D nanomaterials, MXenes have attracted significant interest for use in wearable electronics due to their unique electrical and mechanical properties. However, facile approaches for fabricating MXenes into macroscopic fibers with controllable structures are limited. In this study, we present a strategy for easily spinning MXene fibers by incorporating polyanions. The introduction of poly(acrylic acid) (PAA) into MXene colloids has been found to alter MXene aggregation behavior, resulting in a reduced concentration threshold for lyotropic liquid crystal phase. This modification also enhances the viscosity and shear sensitivity of MXene colloids. Consequently, we were able to draw continuous fibers directly from the gel of MXene aggregated with PAA. These fibers exhibit homogeneous diameter and high alignment of MXene nanosheets, attributed to the shear-induced long-range order of the liquid crystal phase. Furthermore, we demonstrate proof-of-concept applications of the ordered MXene fibers, including textile-based supercapacitor, sensor and electrical thermal management, highlighting their great potential applied in wearable electronics. This work provides a guideline for processing 2D materials into controllable hierarchical structures by regulating aggregation behavior through the addition of ionic polymers.

Little is known about the synthesis of colloidal ternary semiconductor magic-size clusters (MSCs) and quantum dots (QDs) in an aqueous environment. We report here the first synthesis of aqueous-phase CdSeS MSC-380 (displaying sharp optical absorption peaking at ∼ 380 nm) at room temperature and QDs at elevated temperatures. The reaction contains CdCl₂·2.5H₂O, 3-mercaptopropionic acid (MPA, HS–(CH₂)₂–COOH), selenourea (SeU, NH₂–C(Se)–NH₂), and thioacetamide (TAA, CH₃–C(S)–NH₂). Prior to the nucleation and growth (N/G) of QDs, there are clusters formed at 25 °C. The prenucleation-stage clusters are the precursor compound of CdSeS MSC-380 (PC-380). The PC is relatively transparent in optical absorption; in the presence of a primary amine butylamine (BTA, CH₃–(CH₂)₃–NH₂), the PC transforms to absorbing CdSeS MSC-380. At 80 °C, the PC decreases and the N/G of CdSeS QDs appears. The present study paves the way to the aqueous-phase synthesis of ternary CdSeS MSCs and QDs, providing an in-depth understanding of the cluster formation in the prenucleation stage of CdSeS QDs.

Molecular diagnostic technologies empower new clinical opportunities in precision medicine. However, existing approaches face limitations with respect to performance, operation and cost. Biological molecules including proteins and nucleic acids are being increasingly adopted as tools in the development of new molecular diagnostic technologies. In particular, leveraging their complementary properties—the functional diversity of proteins and the precision programmability of nucleic acids—a wide range of protein-nucleic acid hybrid nanostructures have been developed. These hybrid structures take diverse forms, ranging from one-dimensional to three-dimensional hybrids, as static assemblies to dynamic machines, and possess myriad functions to recognize target biomarkers, encode vast information and execute catalytic activities. Motivated by recent advances in this area of molecular nanotechnology, we review the state-of-art design and application of various types of protein-nucleic acid hybrid nanostructures for molecular diagnostics, and present an outlook on the challenges and opportunities for emerging pre-clinical and clinical applications, highlighting the promise for earlier detection, more refined diagnosis and highly tailored treatment decision that ultimately lead to improved patient outcomes.

Direct ethanol fuel cells (DEFCs) have drawn attention for their simplicity, rapid start-up, high power density and environmental friendliness. Despite these advantages, the widespread application of DEFCs faces challenges, primarily due to the inadequate performance of anode and cathode catalysts. Pd-based materials have shown exceptional catalytic activity for both the ethanol oxidation reaction (EOR) and the oxygen reduction reaction (ORR). Alloying noble metals with rare earth elements has emerged as an effective strategy to further enhance the catalytic activity by modulating the electronic structure. In this study, we synthesized a series of palladium-rare earth (Pd₃RE) alloys supported on carbon to serve as bifunctional catalysts that efficiently promote both ORR and EOR. Compared to Pd/C, the Pd₃Tb/C catalyst exhibits 3.1-fold and 1.8-fold enhancement in activity for ORR and EOR, respectively. The charge transfer in the Pd₃Tb/C results in an electron-rich Pd component, thereby weakening the binding energy with oxygen species and facilitating the two reactions.