ACS Applied Nano Materials最新文献

Metal–organic frameworks (MOFs) provide a versatile platform for incorporating multiple metal ions within a single crystalline framework, yet achieving spatial and stoichiometric order in heterometallic nodes remains a synthetic challenge. Building on our previously reported, highly thermally stable Ce/Ti bimetallic MOF NU-3000, we identified and isolated two additional crystalline phases, NU-2998 and NU-2999, that arise from the same Ce/Ti nanocluster precursor under modified solvothermal conditions. Systematic variation of reaction temperature, time, solvent ratio, and modulator concentration directs the assembly of these distinct frameworks. Structural analysis and comprehensive characterization studies reveal that these MOFs each feature an unreported nodal geometry with nanocavities of different sizes. NU-2998 even adopts an unreported topology, denoted nui, that features an elongated pore spanning 4 nm. Together, these findings establish a synthesis route that starts with a nanocluster and ends with a set of bimetallic MOFs, offering a glimpse into the pathway-dependent assembly of multimetallic porous materials. We evaluated the thermal stability of each additional analogue and compared them to NU-3000, providing further insight into material stability. NU-3000 maintained the highest thermal stability and was evaluated as a catalyst for CO oxidation at elevated temperatures.

To address challenges in complex electromagnetic environments, the development of high-efficiency microwave absorbers has become a major research direction in electromagnetic protection. In this study, NiCo₂O₄/ZnO heterostructure nanocomposites were synthesized via a two-step hydrothermal method, in which ZnO nanoparticles were anchored on the needle-like surface of NiCo₂O₄. Compared with pure urchin-like NiCo₂O₄, NiCo₂O₄/ZnO heterostructure composites exhibited lower reflection loss and a broader effective absorption bandwidth. These improvements arise from nanoscale heterointerfaces between NiCo₂O₄ and ZnO, abundant oxygen vacancies, and synergistic loss mechanisms, all of which promote multiple reflections and scattering of electromagnetic waves. Specifically, NiCo₂O₄/ZnO-25% nano heterostructure composites achieved an RL_min of −59.45 dB at 17.14 GHz, with an extended effective absorption bandwidth of 3.8 GHz, owing to the optimized impedance matching. Furthermore, tuning the ZnO content in the NiCo₂O₄/ZnO heterostructure composites enables controllable frequency shifting of the microwave absorption peak across the C-, X-, and Ku-bands. This work offers a feasible strategy and experimental support for designing lightweight, high-performance microwave absorbers, and broadens the application prospects of multicomponent oxide nanocomposites in electromagnetic protection and stealth technologies.

Pesticide residues in vegetables pose serious human health risks, thereby underscoring the need for developing rapid, cost-effective, sensitive, and nondestructive analysis methods for on-site pesticide detection. Here, we report a wearable adhesive SERS-active finger cap created by decorating silver nanopopcorns (AgNPCs) and molybdenum carbide (Mo₂C) nanoparticles on flexible aluminum tape (AT) to constitute the hybrid AgNPCs/Mo₂C@AT SERS platform for reliable detection of the toxic pesticide fipronil (FP). The synergistic electromagnetic and chemical enhancements of the AgNPCs/Mo₂C composite greatly amplify SERS signals, while strong adhesion and flexibility ensure robust nanoparticle retention and efficient analyte collection from irregular surfaces, The AgNPCs/Mo₂C@AT SERS finger cap demonstrates a broad detection range from 10^–10 to 10^–4 M with an enhancement factor of 1.90 × 10⁹ and an ultralow limit of detection of 1.16 × 10^–10 M, which is far below the regulatory thresholds set by the European Union and China. Besides, it exhibits superior signal uniformity (RSD = 8.81%), good reproducibility (RSD = 8.01%), and excellent storage stability, which can retain 70% of its original SERS activity after 14 days. Its flexibility allows for its intimate contact with curved surfaces to enable efficient FP residue detection on tomatoes and chilies using a simple “paste, press, and peel” method. Overall, the proposed wearable SERS finger cap represents a low-cost, user-friendly, amd highly sensitive SERS platform for real-time on-site pesticide detection with broad applications in food safety and environmental monitoring.

The abilities of a strong redox reaction and efficient selective removal of harmful molecules are two important factors in the photodegradation of organic pollutants for ideal environmental remediation. However, it is still an arduous pursuit to acquire shape-selective photocatalytic performance for photocatalysts owing to the randomly destructive effect of free radicals generated on the surface of catalysts toward both harmful pollutants and eco-friendly organisms in nature. Herein, an eco-friendly photocatalyst (TiO₂ NSs@Y-zeolite) was synthesized by engineering the highly active {001} facet exposure of TiO₂ nanosheets (NSs) via controlling fluorine doping, followed by fixation inside the Y-zeolite crystals. The as-prepared zeolite-fixed TiO₂ NSs demonstrated outstanding eco-friendly capabilities with fairly effective shape-selective photodegradation activity. The aniline pollutant can be completely removed over the catalyst under 360 min UV–vis illumination in the aniline and chlorophyll mixed aqueous solution, while the eco-friendly chlorophyll macromolecules remain nearly unharmed with a lower photodegradation rate of 5%. The excellent shape-selective properties of the photocatalyst are ascribed to the sieving effect of the micropores in the Y-zeolite shelter, which only allows the aniline small molecules to access the catalyst surface while preventing the bulky chlorophyll from passing through. We found that it is photogenerated hole carriers, rather than electrons, that are rapidly transferred to the active {001} facets of TiO₂ NSs driven by the built-in internal electric field (IEF) to undergo a strong redox reaction. The strong interaction between aniline and the exposed {001} facets, with some possible planar adsorption state, was also first found due to the dipole–dipole/coordination interactions between the nitrogen atom of the dipolar aniline and the Ti⁴⁺ site at the surface of the dipolar TiO₂ lattice, which is favorable to the efficient photodegradation of the pollutant aniline.

Regulating the dispersion of metal nanoparticles in supported metal catalysts is crucial for enhancing the catalytic activity and selectivity for a variety of hydrogenation reactions. However, the application of these supported catalysts in achieving highly efficient catalytic hydrogenation reactions still remains ambiguous due to the difficulties associated with stability and controlling the distribution of active catalytic sites onto the support materials. Herein, we report a cost-effective methodology to obtain Au nanoparticles (Au NPs)-supported mesoporous SiO₂ (Meso-Au/SiO₂) catalysts with highly exposed active sites for enhancing the catalytic selectivity toward hydrogenation of 4-nitrophenol(4-NP) to 4-aminophenol (4-AP) as a model catalytic system. The results revealed that by increasing Au-metal loading in Au/meso-SiO₂ catalysts, the metal dispersion and catalytic activity can be effectively tailored. At an optimum Au-loading (about 6.04 wt %), the Au/meso-SiO₂ catalyst exhibited maximum catalytic activity with a rate constant (K_app) of 0.432 min^–1 and a good stability of about 40% after four cycles compared with other obtained catalysts. Importantly, the observed K_app value is much greater compared with the commercial Au/γ-Al₂O₃(c) and Au/SiO₂(c) catalysts under similar conditions. This facile approach enables designing highly efficiently supported catalysts with exposed active sites for maximizing catalytic activity for efficiently removing organic pollutants from aqueous solutions.

Soil salinization threatens global food security, making the development of strategies for improving plant salt stress tolerance an urgent research priority. Nitrogen-doped carbon dots (N-CDs), as carbon-based nanomaterials, have exhibited potential agricultural application value; however, the underlying mechanism by which they regulate plant salt tolerance remains elusive. In this study, N-CDs were synthesized via a hydrothermal method using citric acid and triethylenetetramine as precursors. Subsequent experiments were performed on Arabidopsis thaliana and apple “Orin” callus. The results demonstrated that N-CDs with amino-group-rich surfaces could enhance plant salt stress tolerance. Mechanistically, N-CDs induced sphingolipid/calcium channel protein-dependent Ca²⁺ influx, which in turn activated the salt stress response pathway. Furthermore, we preliminarily detected the interaction between N-CDs and glycosylinositol phosphorylceramides (GIPCs) with a dissociation constant (K_d) of 1.34 mM. Collectively, this study reveals the molecular mechanism through which N-CDs enhance plant salt tolerance via the “sphingolipid-Ca²⁺” signaling pathway.

Metal–organic frameworks (MOFs) have attracted attention for carbon dioxide (CO₂) capture due to their large surface area and easily regulated pores. However, their application still suffers from a low CO₂ adsorption capacity and short lifespan under humid environments. We herein report on a promising strategy in which polyethylenimine (PEI) is postsynthetically grafted onto Zr-based organic frameworks (UiO-66-NH₂) ligands to develop the nanoporous UiO-66-NH-acetyl (Ac)-PEI for CO₂ adsorption. UiO-66-NH-Ac-PEI had a high specific surface area of 728.27 m²/g, with the particle size concentrated between 20 and 55 nm. Benefiting from the chemistry and environment created within the pores, UiO-66-NH-Ac-PEI exhibited a high CO₂ adsorption capacity of 2.26 mmol/g at 298 K, and 1 bar, and an excellent CO₂/N₂ selectivity of 42. Breakthrough experiments demonstrated that nanoporous UiO-66-NH-Ac-PEI can efficiently separate CO₂ from N₂ under high-humidity conditions. The CO₂ adsorption mechanisms are thoroughly analyzed by density functional theory calculations, which demonstrate that the aminated pores have an excellent affinity for CO₂; thus, it is preferentially adsorbed by the MOFs. This study significantly advances the strategy of designing nanoporous Zr-MOF by grafting amine moieties onto its backbone ligands, thereby enabling strong binding with CO₂ in humid environments.

CeO₂ is an n-type semiconductor and an excellent candidate as an electron transport layer for perovskite solar cells. However, it is challenging to fabricate high-quality CeO₂ nanotubes (NTs) to meet the specific applications. Here, we report an approach to fabricating CeO₂ nanotubes (NTs) using ZnO nanowires, enabling precise control over nanotube geometry. The resulting CeO₂ NTs are infiltrated with MAPbI₃ to form confined MAPbI₃ nanowires in the CeO₂ NTs structure for nanowire-based perovskite solar cells. Devices based on the confined perovskite achieve power conversion efficiencies of 11.5% and exhibit significantly improved air stability compared to planar thin-film counterparts. These results demonstrate that CeO₂ NTs can serve as an efficient electron transport layer in a protective scaffold, highlighting the improved stability in perovskite nanowire solar cells.

The pursuit of sustainable technologies for both environmental purification and energy storage has driven the development of multifunctional nanomaterials capable of delivering high performance in diverse applications. In this study, a g-C₃N₅/MnCo₂S₄ nanocomposite was successfully fabricated using a simple indirect-hydrothermal method and systematically assessed for its dual functionality in photocatalytic pollutant removal and electrochemical energy storage. Under visible-light irradiation, the composite displayed superior photocatalytic activity toward Congo Red dye, achieving a degradation efficiency of 92.45% within 60 min. In parallel, the material exhibited superior capacitive behavior, delivering a specific capacitance of 1188.57 F g^–1 at 1 A g^–1 along with long-term cycling stability over 10,000 charge–discharge cycles. Morphological analyses through FE-SEM and HR-TEM indicated a homogeneous integration of MnCo₂S₄ rock-like structures onto the g-C₃N₅ layered structures in the nanocomposite, which results in increased surface area, as verified by BET analysis. Impedance measurements confirmed a markedly reduced internal resistance in the nanocomposite, indicating efficient ion transport and improved electrical conductivity compared to their individuals. The fabricated asymmetric device exhibits a high energy density of 22.81 Wh kg^–1 at 599.3 W kg^–1 power density. Collectively, these findings demonstrate that the g-C₃N₅/MnCo₂S₄ nanocomposite is a highly effective, low-cost, multifunctional material with strong potential for synergistic applications in wastewater treatment and energy-storage systems. The work also emphasizes the broader prospects of engineering g-C₃N₅-based materials for next-generation environmental and energy technologies.

Room-temperature liquid metals (LMs), predominantly composed of gallium (Ga), possess distinctive characteristics that integrate metallic conductivity with liquid fluidity under ambient conditions. Their remarkable deformability, printability, safety, nontoxicity, and self-healing capabilities have broken through the constraints of traditional materials, facilitating their application across a wide range of fields. However, the functional characteristics of LMs are significantly affected by their nanoscale surface properties, which are determined by factors including composition, phase transformation, and surface atomic distribution. Herein, we propose a strategy to modulate the surface atomic distribution and properties of LMs by employing high-entropy trends. Bismuth (Bi) and zinc (Zn) were incorporated into eutectic eGaInSn to produce an entropy-enhanced multicomponent LM. The heat treatment methods enhance the dissolution and dispersion of Bi and Zn atoms within LMs, thereby ensuring a uniform distribution of the constituent elements. This process alters the atomic configuration and electronic structure of the surface, thereby regulating its electrodynamic properties. The strategy of high-entropy trends enhances the surface characteristics, including optical, electrical, mechanical, wettability, work function, thermal, and electrochemical properties. This approach provides novel methodologies for the functional design and application of LMs.