ACS Applied Nano Materials最新文献

It is well-known that metal ions (such as magnesium (Mg²⁺) and lithium (Li⁺) ions) are generally used to alleviate the problems of zinc oxide nanoparticles (ZnO NPs). Herein, the Mg²⁺ and Li⁺ ions are codoped into the ZnO NPs to simultaneously passivate the surface defects and tune the conduction band (CB) of NPs, which is confirmed by the spectra of X-ray photoelectron spectroscopy (XPS), electron spin resonance (EPR), and ultraviolet photoelectron spectroscopy (UPS). The LiMgZnO NPs can efficiently keep the excitons generated from the quantum dot (QD) emissive layer (EML) from being severely quenched and afford QD light-emitting diodes (QLEDs) with a balanced charge carrier. As a result, the use of LiMgZnO electron transport layer (ETL) achieves high-performance indium phosphide (InP)-based QLEDs with a luminance (L) of ∼7000 cd m^–2 at 6 V and a peak external quantum efficiency (EQE) of ∼12.0%, higher than those of devices made by the MgZnO ETL (L = ∼3300 cd m^–2 and EQE = 8.4%). Therefore, we believe that the LiMgZnO ETL can be used inside the InP-based QLEDs, affording its devices with improved performance.

The growing deployment of 5G communication systems has sharply escalated the demand for high-performance electromagnetic interference (EMI) shielding materials with outstanding thermal stability and efficiency. Carbon fiber (CF), recognized for its cost-effectiveness and environmental sustainability, has shown significant promise in the development of EMI shielding composites. Nevertheless, achieving a balance of lightweight structure, superior shielding efficiency, and thermal endurance remains a formidable challenge. In this study, a streamlined fabrication process was utilized to develop a multifunctional, lightweight nanocomposite. MXene was synthesized via in situ etching of the MAX phase with hydrofluoric (HF) acid, followed by the construction of a three-dimensional (3D) cocarbonized network comprising interconnected CF, MXene, and MXene-derived phases (CMXene) via a straightforward cocarbonization process. The polyimide (PI) matrix was uniformly infused into the porous framework using a precisely controlled impregnation technique, resulting in a PI-based nanocomposite with exceptional EMI shielding performance. At a filler content of 14.3 wt % and a thickness of 1.7 mm, the nanocomposite demonstrated an EMI shielding effectiveness (EMI SE) of 73.8 dB in the X-band ranging from 8.2 to 12.4 GHz, maintaining 63.3 dB even at high temperatures of 400 °C, reflecting an 85.8% retention rate. This ultralight nanocomposite, characterized by excellent EMI shielding efficiency and robust thermal stability, offers significant potential for advanced applications in electronic devices, such as battery management systems in energy vehicles and in-vehicle communication modules, to ensure system stability and prevent EMI-induced signal disruption.

Hydrogen evolution reaction (HER) plays a pivotal role in the electrochemical decomposition of water, necessitating the utilization of a catalyst that combines efficiency, durability, and cost-effectiveness. Due to their affordable cost and exceptional activity, transition metal dichalcogenides (TMDs) have garnered significant attention for their potential in HER. Unfortunately, the TMD materials are found inactive in alkaline conditions. Furthermore, for the direct application in HER, the substrates adopted in the synthesis of the TMD materials are still expensive or even precious metals, which restricts their industrial applications. We have successfully batch-synthesized layered 1T-TaS₂/Cu₂S heterostructures on industrial copper foil substrates through a simple chemical vapor deposition method. The growth temperature allows convenient control of the concentration of S vacancies in 1T-TaS₂, providing relatively high HER performance in alkaline electrolyte; it exhibits an overpotential of 144 mV. As reported, the performance of 2H-phase TMDs in HER is far from satisfactory due to the inert base planes. Here, utilizing the same approach, we achieved the synthesis of 2H-MoS₂/Cu₂S and 2H-WS₂/Cu₂S heterostructures, with comparable overpotentials of 169 and 177 mV, respectively, illustrating the universality of the method and HER applications. In addition, its easy availability and low usage price make the industrial-level application more practical.

Developing transition-metal sulfides with optimized surface structures shows great potential for boosting both oxygen reduction (ORR) and oxygen evolution (OER) reactions but remains challenging due to the lack of effective synthesis strategies. This limitation results in a suboptimal performance for most reported transition-metal sulfide catalysts. Herein, NiCo₂S₄ ultrafine nanosheets (NCS-SP) were obtained through conducting vulcanization treatment over nickel–cobalt hydroxide nanosheets (NiCo–OH) prepared in advance via a clean solvothermal synthesis, during which sulfur powder was employed as the sulfur source. NCS-SP integrates multiple catalytic advantages simultaneously, including the morphology structure of ultrafine nanosheets, excellent hydrophilia, abundant oxygen vacancies, and stable spinel structure, endowing NCS-SP to be an excellent bifunctional catalyst for ORR and the OER, with a smaller potential difference (ΔE) than Pt/C + RuO₂. The work may not only highlight the significance of multistrategy synergy on improving catalytic performance but also pave the way for developing cost-effective and efficient bifunctional catalysts.

Platinum (Pt) nanoparticles (NPs) are an indispensable catalyst in polymer electrolyte fuel cells (PEFCs), but their durability remains a critical challenge. This study systematically evaluated the effect of the gasket thickness (d_g) in the measurement cell on the detection responsivity of online inductively coupled plasma mass spectrometry (ICP-MS) measurement using constant-current anodic pulse dissolution tests of Cu and potential cycling tests of Pt. While a smaller d_g enhanced the detection responsivity, no significant improvement was observed for d_g ≤ 100 μm. A deconvolution process was successfully used to reconstruct the original dissolution signals, enabling in situ evaluation of the dissolution behavior of bulk Pt and Pt NPs, even with broadened detection profiles. The effect of d_g on the electrochemical measurements, including the solution resistance (R_sol) and cyclic voltammogram (CV), was also investigated. Larger d_g reduced R_sol and mitigated the influence of side reactions. The latter allowed accurate CV shapes to be obtained, enabling reliable analysis of the dissolution behavior of Pt. A Pt/C catalyst (Pt NPs) was evaluated under potential cycling conditions using the optimized online ICP-MS conditions. The dissolution behavior of the Pt/C catalyst was consistent with that of bulk Pt, but the Pt/C catalyst dissolved at significantly lower potentials than bulk Pt owing to the Gibbs–Thomson effect. These results highlight the importance of optimizing the experimental conditions for accurately assessing the dissolution behavior of NPs. This study provides a foundation for designing high-durability catalysts to extend the longevity and enhance the performance of PEFCs by enabling precise in situ monitoring of the dissolution mechanism.

In response to the growing challenges posed by increasingly severe electromagnetic radiation environments and diverse personal thermoregulation requirements, the development of wearable devices integrating electromagnetic interference (EMI) shielding and thermal management functionalities has become critical for enhancing human comfort and safety. Inspired by the hierarchical structure of natural leaves, we present a multifunctional wearable material composed of MXene/polyaniline (PANI)/polydopamine (PDA) on a flexible activated carbon fabric (ACC) substrate. This material is fabricated through a facile yet efficient mixed-dimensional assembly strategy, combining two-dimensional (2D) MXene nanosheets with one-dimensional (1D) PANI. The hierarchical architecture of the material mimics the biological structure of leaves, with ACC fabric serving as the robust xylem-like substrate, PANI acting as the phloem-like supporting layer, and MXene nanosheets forming the protective outer layer. The amino groups ( (−NH₂) on PANI function as binding sites, facilitating the formation of hydrogen bonds with both PDA and MXene, thereby enhancing interfacial adhesion and mechanical stability. Furthermore, the synergistic combination of PANI’s inherent conductivity and MXene’s exceptional electrical properties significantly improves the overall conductive network of the fabric. The resulting MXene/PANI/PDA@ACC (MPPA) fabric demonstrates outstanding performance, including high electrical conductivity (384.6 S/m), superior EMI shielding effectiveness (average of 45.81 dB), efficient Joule heating (reaching 94 °C at 5 V), and excellent thermal camouflage capabilities (infrared emissivity of 0.421). Notably, the fabric retains exceptional flexibility, mechanical durability, breathability, and moisture permeability, ensuring superior comfort even under complex environmental conditions. These combined properties position the MPPA fabric as a promising candidate for next-generation wearable technologies, addressing the dual demands of electromagnetic protection and adaptive thermal management.

Transition-metal sulfides exhibit significant potential as catalysts in the fields of photocatalysis, sensors, and supercapacitors. In this work, heterojunction CuS@Cu₂MoS₄ nanocubes were synthesized through the strategy of template-assisted and hydrothermal approaches for nonenzymatic electrochemical glucose sensing. First, Cu₂O nanocubes (NCs) were synthesized as the template, followed by surface sulfidation to form core–shell Cu₂O@CuS NCs. Afterward, the Cu₂O core was selectively etched, followed by one-step hydrothermal growth of Cu₂MoS₄ on the CuS surface. In this way, heterojunction hollow core–shell CuS@Cu₂MoS₄ NCs were synthesized. The hollow structure can enhance mass transport and provide additional active reaction sites, while the heterostructure between CuS and Cu₂MoS₄ can amplify their synergistic effects, thereby improving conductivity and electrocatalytic activity. For analytical applications, the synthesized CuS@Cu₂MoS₄ NCs exhibit extraordinary electrocatalytic activity toward glucose oxidation. Under optimized conditions, the CuS@Cu₂MoS₄ NC-modified glassy carbon electrode demonstrates a broad linear response range from 0.002 to 23 mM for glucose determination, with a detection limit of 3.1 μM. In addition, real sample analysis reveals a recovery of 97.06–103.86%, indicating its promise for quantitative analysis in practical applications.

Once the vapor pressure of a volatile liquid exceeds the ambient air pressure, the liquid droplets vaporize. This principle has led to the development of a type of nanodroplets that can transform into microbubbles upon ultrasound exposure. The unique phase-transition properties of these nanodroplets endow them with exceptional ultrasound imaging capabilities, while the mechanical effects of cavitation enhance their performance in targeted drug delivery. In this review, we will delve into the composition and phase transition mechanisms of these nanodroplets, as well as their potential clinical applications. Our discussion will not only highlight the diagnostic and therapeutic uses of ultrasound-activated nanodroplets for various medical conditions, but also address the challenges and potential strategies for their clinical translation.

The nanoscale hollow porous structure exhibits thermal conductivity similar to silica aerogel due to its lower density and high closed cavity structure. However, the traditional preparation methods of such structures face major challenges in achieving accurate morphological control under high-concentration synthesis conditions. In this study, a series of multiblock copolymers were synthesized, which can form a stable water/oil/water vesicle system with the oil phase over a wide concentration range and can be used as a template to synthesize mesoporous silica hollow spheres at ultrahigh precursor concentrations. By controlling the ethanol content in the reaction formation process, we can control the size, stacking mode, and adhesion degree of silica hollow spheres and finally prepare controllable particle size nonadhesion silica hollow spheres and aerogels with different stacking morphology, particle size, and adhesion degree of silica hollow spheres as structural elements. Due to their hollow and porous structural units and the three-dimensional network skeleton structure similar to conventional aerogels, our aerogels exhibit extremely low thermal conductivity (37.8 mw k^–1 m^–1) and density (0.056 g cm^–3), while the large skeleton size allows our aerogel to have extremely high structural strength (Young’s modulus of 117.9 MPa) and can be dried directly under atmospheric pressure. In addition, we also explored the reasons for the formation of hollow structures and what kind of block structures can be used to construct hollow structures, which will provide theoretical directions for the synthesis of hollow structures by soft templates.