ACS Applied Nano Materials最新文献

Gas therapy based on carbon monoxide (CO) is an emerging anticancer strategy. However, conventional CO donors suffer from uncontrolled gas release and poor therapeutic efficacy. Developing a multimodal therapeutic system combining CO gas therapy and phototherapy modalities, which is of great significance for improving the efficacy of tumor treatment. Herein, a supramolecular nanoparticle loaded with BODIPY photosensitizer (BOD-GP5⊃HFMI) was developed by host−guest self-assembly of galactosylated pillar[5]arene (GP5) and 3-hydroxyflavone derivative (HFMI). Galactose modification enhanced cellular uptake in B16F10 melanoma cells via glucose transporter-1-mediated recognition. Upon NIR irradiation (685 nm), the generated ROS trigger the degradation of the benzene ring structure of HFMI to release HFMI and BODIPY. The released BODIPY converted NIR light energy into thermal energy and the generated ROS, where the generated ROS trigger HFMI to release CO gas, thereby achieving a spatiotemporally controlled photodynamic/photothermal/CO gas multimodal synergistic cancer therapy. Notably, the released CO could cyclically amplify intracellular ROS levels via mitochondrial dysfunction. Studies in vitro and in vivo exhibited that BOD-GP5⊃HFMI achieved an enhanced cancer therapeutic effect without obvious systemic toxicity. This NIR light-triggered, cyclic-amplifying strategy provides a new paradigm for synergistically enhanced cancer therapeutic effectiveness.

The green and clean hydrogen energy carrier can be produced rapidly through ammonia borane hydrolysis under mild conditions. Essential to such rapid production is the development of efficient nanocatalysts. Herein, Pt and Cu were dispersed on the Co₃O₄ support by the impregnation method to prepare the PtCu/Co₃O₄ nanocatalyst for ammonia borane hydrolysis. The introduction of Cu effectively promoted the reduction of Pt species to metallic Pt⁰, enhancing the hydrogen generation rate remarkably. The synergistic effect between Pt and Cu further boosted the hydrogen generation rate, endowing the catalyst with outstanding catalytic activity. The optimized PtCu(0.5)/Co₃O₄ catalyst presented superior catalytic performance, and the TOF value achieved 6310 min¹ at 298 K. The catalyst retained high catalytic activity after 5 cycles of reuse. This work provides referable ideas for nanocatalyst design, preparation, and the study of structure−activity relationships.

In high-temperature fracturing operations, the rapid decomposition of strong oxidant breakers causes premature viscosity loss of fracturing fluids, severely impairing proppant placement. Currently, most delayed gel-breaking systems rely on polymeric shell materials to physically encapsulate oxidants. However, such polymer-based systems suffer from a dual failure mechanism at elevated temperatures: (i) the polymer shell softens and swells due to intensified thermal motion, losing its structural integrity; and (ii) the encapsulated strong oxidant (e.g., ammonium persulfate) aggressively attacks the polymer backbone, causing oxidative degradation of the shell material and accelerating burst release. These two synergistic effects render “polymer-encapsulated oxidants” fundamentally unworkable in high-temperature reservoirs. To radically overcome this material bottleneck, we propose for the first time a non-polymeric controlled-release strategy based on the synergistic effect of “inorganic mesoporous confinement and oil-phase isolation.” Rigid hollow mesoporous silica microspheres (HMSS) with nanoscale mesoporous shells are employed as inorganic structural carriers, which exhibit exceptional resistance to both high temperature and strong oxidants. APS is loaded via impregnation, followed by hydrophobic surface modification and dispersion in white oil to construct an emulsion-type release system. This system leverages the rigid silica skeleton for outstanding thermal and chemical stability, while the oil-phase interfacial barrier effectively prevents premature APS-aqueous contact. Results show that at 90 °C with 2.5 wt % hydrophobic particles, the cumulative release reaches 62% over 12 h, demonstrating excellent sustained-release characteristics. At 100 °C, the system extends the complete gel-breaking time to ∼8 h, which is 7 times longer (i.e., an 8-fold increase) than that of directly added APS. By completely abandoning organic polymer shellswhich are both thermally labile and susceptible to oxidative attackand instead employing inorganic mesoporous silica combined with an oil-phase barrier, this work fundamentally resolves the long-standing challenge of premature breaker release under high-temperature oxidizing conditions, offering a nanoscale carrier-based, structurally simple, highly robust, and precision-release paradigm for deep high-temperature reservoir stimulation.

We report a systematic study of hydrothermally synthesized Mo_1−xW_xS₂ alloys (x = 0−1), correlating their structural, vibrational, morphological, and electrochemical properties with composition. The materials were prepared using ammonium tetrathiomolybdate and ammonium tetrathiotungstate precursors in an octylamine-mediated hydrothermal process at 200 °C. X-ray diffraction revealed that all samples exhibited expanded interlayer spacing, with low-angle reflections (∼9°−17°) indicative of non-ideal stacking associated with ammonium/amine intercalation rather than conventional 2H ordering. Raman spectroscopy confirmed the presence of the A_1g and $E_{2g}^1$ vibrational modes, which shifted and broadened with the composition. The Mo-rich and W-rich samples displayed characteristic MoS₂- and WS₂-like signatures, respectively, whereas the intermediate compositions exhibited multiple vibrational components and peak broadening, reflecting compositional disorder and mixed bonding environments. Electron microscopy revealed a composition-dependent morphological evolution from well-defined nanosheets to disordered, partially exfoliated structures at intermediate compositions. These structural changes influenced the electrochemical behavior probed by cyclic voltammetry and electrochemical impedance spectroscopy Mo70W30 showed the lowest charge-transfer resistance (R_ct ≈26.71 Ω), indicating favorable charge-transfer kinetics associated with moderate structural disorder and Mo−W electronic interactions. Here, Mo_xW_y denotes the nominal Mo/W molar ratio of the precursors. In contrast, Mo30W70 exhibited the highest double-layer capacitance (C_dl ≈21.64 μF), consistent with its increased surface accessibility and higher defect density. The results demonstrate that the electrochemical performance is governed by the balance between structural disorder, interlayer accessibility, and electronic transport. These results establish a structure−composition−property relationship in Mo_1−xW_xS₂ alloys and demonstrate that the intermediate compositions largely determine the functional response.

Photocatalytic hydrogen production represents a promising strategy for the sustainable conversion of solar energy into chemical fuels, yet its efficiency is often limited by rapid charge recombination and narrow light absorption. To address these challenges, an all-solid-state Z-scheme ZnIn₂S₄/reduced graphene oxide/Nb₂O₅ (ZIS/rGO/NO) heterojunction was constructed via hydrothermal method. In this hierarchical structure, two-dimensional rGO serves as an efficient electron-transfer bridge between ZIS nanosheets and NO nanoplates, facilitating rapid charge separation and migration while suppressing electron−hole recombination. The optimized ZIS/rGO/NO photocatalyst achieves a remarkable hydrogen evolution rate of 5.2 mmol·g⁻¹·h⁻¹ under visible-light irradiation. The resulting hydrogen evolution rate is 8.7 and 3.5 times greater than that of pure ZIS and the binary ZIS/NO composite, respectively. Furthermore, an apparent quantum efficiency (AQE) of 15.3% was achieved at 420 nm. The synergistic interplay between the Z-scheme heterojunction and graphene mediator offers an effective strategy for designing highly active and stable photocatalysts for solar energy conversion.

Detection of trace chemicals, heavy metals, biomolecules, explosives, and threats such as nerve agents and narcotics is a challenging task. The selection criteria for candidate technology include sensitive detection capability with ultra-low limits of detection, unambiguous selectivity, and a portable, field-deployable platform. Surface enhanced Raman spectroscopy (SERS) has emerged as a highly useful and proven method to meet the detection requirements. The usually weak Raman signal due to small cross-sections of most analytes is amplified sufficiently in SERS for implementation in practical systems. This amplification is enabled by sufficiently close metallic nanostructures placed on a backup material, called a SERS substrate. The current bottleneck to widespread practical implementation of SERS is the lack of reliable substrates at reasonable prices, as elaborate schemes are needed to prepare the desired nanofeatures to achieve the SERS enhancement. An ideal SERS substrate must have a high density of hot spots over the active detection area, a high enhancement factor uniformly across the active area, and reproducible results with fabrication amenable to large-scale manufacturing that can result in low cost. Direct write printing of metallic nanoparticles on paper and other flexible substrates as well as rigid substrates such as silicon and glass has been emerging as a viable technique to meet the above requirements. This article presents a detailed review of printed SERS substrates and their applications, along with the operating principles.

Formic acid (FA), when derived from captured CO₂ and renewable H₂, is a promising liquid hydrogen carrier, but its sustainable use requires catalysts that enable fast, CO-free, and additive-free hydrogen release under mild conditions. Herein, we report a nanoscale La₂O₃-modified porous N-doped carbon-anchored ultrafine Pd nanoparticle catalyst La₂O₃-engineered porous carbon-nitrogen-supported Pd catalyst, Pd−La₃CN-750, for efficient FA dehydrogenation. The introduced nanosized La₂O₃ species are uniformly dispersed on the porous carbon-nitrogen support, which precisely regulates the interfacial microstructure of Pd nanoparticles. La₂O₃ incorporation reconstructs the Pd/support interface by creating defect-rich anchoring sites, introducing medium-strength basic sites, and inducing interfacial electron transfer to enrich electron-deficient Pd^δ+ species. As a result, Pd−La₃CN-750 achieves a complete aqueous FA dehydrogenation within 8 min at 313 K, with a TOF of 1431 h⁻¹, a low apparent activation energy of 42.36 kJ mol⁻¹, no detectable CO formation, and stable reusability over seven cycles. In situ DRIFTS and density functional theory calculations reveal a nanoscale interfacial dual-site relay mechanism, in which La−O basic sites activate the O−H bond of FA to generate formate intermediates, while adjacent Pd⁰−Pd^δ+ ensembles promote C−H cleavage, H−H coupling, and H₂ desorption. This interfacial synergy lowers the dehydrogenation barrier while suppressing the CO-forming dehydration route. From a sustainability perspective, the catalyst offers low-temperature atmospheric-pressure operation, eliminates sacrificial additives, maximizes the utilization efficiency of ultrafine Pd active nanoparticles, and produces a CO-free hydrogen stream, while future optimization should address synthesis-stage impacts from hard templating, high-temperature carbonization, alkaline etching, solvent use, and H₂ reduction. This work provides a sustainability-oriented interfacial design strategy for efficient hydrogen release from carbon-recyclable liquid carriers.

Saline-alkali stress impairs plant growth via ROS overaccumulation, while MOF nanozymes offer a promising redox-regulation strategy. In this study, a Ce/Mn-MOF nanozyme was synthesized via a solvothermal method through a bimetallic doping strategy. The reversible valence transitions of bimetallic ions (Ce³⁺/Ce⁴⁺ and Mn²⁺/Mn³⁺) promote electron transfer, endowing the Ce/Mn-MOF with superoxide-like (SOD), catalase-like (CAT), and glutathione peroxidase-like (GPx) activities. It exhibits efficient cascade catalytic capability for reactive oxygen species (ROS) scavenging, enabling the conversion of superoxide radicals (O₂^•−) and hydrogen peroxide (H₂O₂) into less harmful species. Furthermore, the Ce/Mn-MOF demonstrates low toxicity, ensuring good biocompatibility and safety. It also enhances stress tolerance while promoting biological growth by scavenging excess ROS in plants and thereby alleviating oxidative stress. The Ce/Mn-MOF significantly improved the indicators of mung bean under saline‑alkali stress. Photosynthesis with Pn increased by 93.2%, Gsw by 33.3%, and Tr by 34.0%. It raised SOD activity by 66.84% and CAT activity by 39.97%. Meanwhile, the Ce/Mn-MOF can be used in both hydroponic and soil cultivation systems, further demonstrating the applicability of the Ce/Mn-MOF in agricultural practice. This study provides insights into the application of nanozymes and lays a foundation for promoting the diversified application of nanotechnology in modern agriculture.

Boron (B)-based energetic materials are promising for micro-electro-mechanical systems (MEMS) and multifunctional energetic devices because of their high gravimetric heat and volumetric energy density. However, a dense surface boron oxide (B₂O₃) passivation layer hinders ignition and limits energy-release efficiency. During pyrolysis, poly(vinylidene fluoride) (PVDF) generates fluorinated species that remove this layer and trigger a pre-ignition reaction, while bismuth(III) oxide (Bi₂O₃) acts as an oxidizer to enhance reaction and heat release. Here, boron-based Bi₂O₃/PVDF nano-energetic composite films were prepared by ball milling combined with electrospinning, achieving nanoscale dispersion and interfacial coupling. Under a fixed (B/Bi₂O₃):PVDF mass ratio of 30:70, samples with different B/Bi₂O₃ ratios (100:5, 100:10, 100:15, and 100:20) were prepared. All films exhibited excellent hydrophobicity. The films with B/Bi₂O₃ ratios of 100:10−100:15 demonstrated an optimal balance between structural integrity and energetic reactivity. It also showed that no formation of crystalline phases or chemical bonds, indicating that the ternary system is dominated by physical mixing and weak interfacial interactions. Notably, the sample containing 15% Bi₂O₃ exhibited the strongest catalytic effect, reducing the initial oxidation temperature by 173.96 °C compared with the raw boron. Its combustion duration shortened from 3.1 to 2.2 s, and combustion temperature reached 1533 °C. Overall, the ternary system regulates ignition and energy release through fluorination-assisted and interface-enhanced oxidation, offering a strategy for efficient multicomponent boron-based energetic films.

We report a bottom-up strategy, termed nanoprecipitation-solvent neutralization, for the preparation of drug-loaded polymeric nanospheres and nanocapsules for pharmaceutical applications. The method is compatible with hydrolysis-sensitive drug molecules and accommodates pharmaceutically approved polymers and excipients that are water-insoluble across the entire pH range. In this approach, an organic phase containing polymer and, when appropriate, additional hydrophobic components dissolved in glacial acetic acid is combined with an aqueous phase containing a stabilizer, inducing nanoparticle nucleation and growth via the Ouzo effect. Glacial acetic acid serves both as the nanoprecipitation solvent and as a chemically removable species that can be converted into a water-soluble salt through a simple acid−base reaction. Following particle formation, solvent neutralization substantially reduces solvent-removal times relative to conventional evaporation-based nanoprecipitation without the need for specialized equipment. No significant degradation of polymers-drugs, or stabilizers was observed by GPC and HPLC analyses despite the presence of hydrolysis-sensitive bonds. The use of a weak base following the transient acidic step was fundamental for maintaining formulation stability by generating a buffering system in the near-neutral pH range. Mechanistic insights obtained using an environment-sensitive photophysical probe revealed a transition in the medium polarity and pH consistent with efficient solvent-to-salt conversion following nanoparticle formation. The method was effective across systems containing hydrophobic components and enabled the preparation of nanoparticles stabilized with nonionic, anionic, or cationic surfactants, allowing modulation of surface charge. The resulting nanoparticles exhibited diameters ranging from 146 to 272 nm and spherical morphology with smooth surfaces, as confirmed by TEM. The salt formed during solvent neutralization could be readily removed without affecting nanoparticle properties. Overall, this approach establishes a chemically driven route to nanoprecipitation in which solvent removal is not governed by mass transport, providing a simple and versatile platform for the production of polymeric nanoparticles for pharmaceutical applications.