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1.
Nano Lett ; 24(1): 89-96, 2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-37939013

RESUMEN

The ability to target specific tissues and to be internalized by cells is critical for successful nanoparticle-based targeted drug delivery. Here, we combined "stealthy" rod-shaped poly(2-oxazoline) (POx) nanoparticles of different lengths with a cancer marker targeting nanobody and a fluorescent cell internalization sensor via a heat-induced living crystallization-driven self-assembly (CDSA) strategy. A significant increase in association and uptake driven by nanobody-receptor interactions was observed alongside nanorod-length-dependent kinetics. Importantly, the incorporation of the internalization sensor allowed for quantitative differentiation between cell surface association and internalization of the targeted nanorods, revealing unprecedented length-dependent cellular interactions of CDSA nanorods. This study highlights the modularity and versatility of the heat-induced CDSA process and further demonstrates the potential of POx nanorods as a modular nanomedicine platform.


Asunto(s)
Nanopartículas , Nanotubos , Sistemas de Liberación de Medicamentos , Membrana Celular
2.
Nano Lett ; 24(8): 2511-2519, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38373158

RESUMEN

Materials with pseudoelasticity can recover from large strains exceeding their elastic limits during unloading, making them promising damage-tolerant building blocks for advanced nanodevices. Nevertheless, a practical approach to realize controllable pseudoelastic behavior at nanoscale remains challenging. Here, we proposed a grain boundary (GB) engineering approach to endow metallic nanocrystals with a controllable pseudoelasticity. Both in situ nanomechanical testing and atomistic simulations demonstrate that such controllable pseudoelasticity is governed by the extension and contraction of an inherent stacking fault array at the GB. By precisely tuning GB misorientation and inclination, our simulation results reveal that metallic nanocrystals can exhibit tailored pseudoelastic performance across a broad spectrum of GBs in different face-centered cubic metals. These findings enrich our understanding of the intrinsic pseudoelasticity of GBs and provide a GB engineering approach toward metallic materials with reversible deformability.

3.
Adv Funct Mater ; 34(14)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38966003

RESUMEN

4D printing is the 3D printing of objects that change chemically or physically in response to an external stimulus over time. Photothermally responsive shape memory materials are attractive for their ability to undergo remote activation. While photothermal methods using gold nanorods (AuNRs) have been used for shape recovery, 3D patterning of these materials into objects with complex geometries using degradable materials has not been addressed. Here, we report on the fabrication of 3D printed shape memory bioplastics with photo-activated shape recovery. Protein-based nanocomposites based on bovine serum albumin (BSA), poly (ethylene glycol) diacrylate and gold nanorods were developed for vat photopolymerization. These 3D printed bioplastics were mechanically deformed under high loads, and the proteins served as mechanoactive elements that unfolded in an energy-dissipating mechanism that prevented fracture of the thermoset. The bioplastic object maintained its metastable shape-programmed state under ambient conditions. Subsequently, up to 99% shape recovery was achieved within 1 min of irradiation with near-infrared light. Mechanical characterization and small angle X-ray scattering (SAXS) analysis suggest that the proteins mechanically unfold during the shape programming step and may refold during shape recovery. These composites are promising materials for the fabrication of biodegradable shape-morphing devices for robotics and medicine.

4.
Small ; : e2401388, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38634407

RESUMEN

In the past two decades, the application of colloidal semiconductor-metal nanoparticles (NPs) as photocatalysts for the hydrogen generation from water has been extensively studied. The present body of literature studies agrees that the photocatalytic yield strongly depends on the electron donating agent (EDA) added for scavenging the photogenerated holes. The highest reported hydrogen production rates are obtained in the presence of ionic EDAs and at high pH. The large hydrogen production rates are attributed to fast hole transfer from the NP onto the EDAs. However, the present discussions do not treat the influence of EDA-specific surface interactions. This systematic study focuses on that aspect by combining steady-state hydrogen production measurements with time-resolved and static optical spectroscopy, employing 11-mercaptoundecanoic acid-capped, Pt-tipped CdSe/CdS dot-in-rods in the presence of a large set of EDAs. Based on the experimental results, two distinct EDA groups are identified: surface-active and diffusion-limited EDAs. The largest photocatalytic efficiencies are obtained in the presence of surface-active EDAs that induce an agglomeration of the NPs. This demonstrates that the introduction of surface-active EDAs can significantly enhance the photocatalytic activity of the NPs, despite reducing their colloidal stability and inducing the formation of NP networks.

5.
Small ; 20(13): e2306154, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37967353

RESUMEN

Hierarchical superstructures have novel shape-dependent properties, but well-defined anisotropic carbon superstructures with controllable size, shape, and building block dimensionality have rarely been accomplished thus far. Here, a hierarchical assembly technique is presented that uses spinodal decomposition (SD) to synthesize anisotropic oblate particles of mesoporous carbon superstructure (o-MCS) with nanorod arrays by integrating block-copolymer (BCP) self-assembly and polymer-polymer interface behaviors in binary blends. The interaction of major and minor phases in binary polymer blends leads to the formation of an anisotropic oblate particle, and the BCP-rich phase enables ordered packing and unidirectional alignment of carbon nanorods. Consequently, this approach enables precise control over particles' size, shape, and over the dimensionality of their components. Exploiting this functional superstructure, o-MCS are used as an anode material in potassium-ion batteries, and achieve a notable specific capacity of 156 mA h g-1 at a current density of 2 A g-1, and long-term stability for 3000 cycles. This work presents a significant advancement in the field of hierarchical superstructures, providing a promising strategy for the design and synthesis of anisotropic carbon materials with controlled properties, offering promising applications in energy storage and beyond.

6.
Small ; 20(7): e2303300, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37840438

RESUMEN

Combining the methanol oxidation reaction (MOR) and hydrogen evolution reaction (HER) within an integrated electrolytic system may offer the advantages of enhanced kinetics of the anode, reduced energy consumption, and the production of high-purity hydrogen. Herein, it is reported the construction of Ni─MoN nanorod arrays supported on a nickel foam substrate (Ni─MoN/NF) as a bifunctional electrocatalyst for electrocatalytic hydrogen production and selective methanol oxidation to formate. Remarkably, The optimal Ni─MoN/NF catalyst displays exceptional HER performance with an overpotential of only 49 mV to attain 10 mA cm-2 in acid, and exhibits a high activity for MOR to achieve 100 mA cm-2 at 1.48 V in alkali. A hybrid acid/base electrolytic cell with Ni─MoN/NF electrode as anode and cathode is further developed for an integrated HER-MOR cell, which only requires a voltage of 0.56 V at 10 mA cm-2 , significantly lower than that of the HER-OER system (0.70 V). The density functional theory studies reveal that the incorporation of Ni effectively modulates the electronic structure of MoN, thereby resulting in enhanced catalytic activity. The unique combination of high electrocatalytic activity and excellent stability make the Ni─MoN/NF catalyst a promising candidate for practical applications in electrocatalytic hydrogen production and methanol oxidation.

7.
Chembiochem ; 25(10): e202400009, 2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38545627

RESUMEN

Calcium (Ca2+) ions play a crucial role in the functioning of neurons, governing various aspects of neuronal activity such as rapid modulation and alterations in gene expression. Ca2+ signaling has a significant impact on the development of diseases and the impairment of neuronal functions. Herein, the study reports a Ca2+ ion sensor in neuronal cells using a gold nanorod. The gold nanorod (GA-GNR) conjugated glutamic acid developed in the study was used as a nano-bio probe for the experimental and in vitro detection of calcium. The nanosensor is colloidally stable, preserves plasmonic properties, and shows good viability in neuronal cells, as well as promoting neuron cell line growth. The cytotoxicity and cell penetration of the nanosensor are studied using Raman spectroscopy, brightfield and darkfield microscopy imaging, and MTT assays. The quantification of Ca2+ ions in neuronal cells is determined by monitoring the surface plasmon resonance (SPR) of the GA-GNR. The change in the intensity profile in the presence of Ca2+ incubated neurons was effectively used to develop a portable prototype of an optical Ca2+ sensor, proposing it as a tool for neurodegenerative disease diagnosis and neuromodulation evaluation.


Asunto(s)
Calcio , Ácido Glutámico , Oro , Nanotubos , Neuronas , Oro/química , Calcio/metabolismo , Calcio/análisis , Neuronas/metabolismo , Neuronas/citología , Neuronas/efectos de los fármacos , Nanotubos/química , Ácido Glutámico/análisis , Resonancia por Plasmón de Superficie , Animales , Técnicas Biosensibles , Humanos , Iones/análisis , Iones/química , Supervivencia Celular/efectos de los fármacos
8.
Chemistry ; : e202400496, 2024 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-38864360

RESUMEN

The prodigious employment of fossil fuels to conquer the global energy demand is becoming a dreadful threat to the human society. This predicament is appealing for a potent photocatalyst that can generate alternate energy sources via solar to chemical energy conversion. With this interest, we have fabricated a ternary heterostructure of Ti3C2 nanosheet modified g-C3N4/Bi2O3 (MCNRBO) Z-scheme photocatalyst through self-assembly process. The morphological analysis clearly evidenced the close interfacial interaction between g-C3N4 nanorod, Bi2O3 and Ti3C2 nanosheets. The oxygen vacancy created on Bi2O3 surface, as suggested by XPS and EPR analysis, supported the Z-scheme heterojunction formation between g-C3N4 nanorod and Bi2O3 nanosheets. The collaborative effect of Z-scheme and Schottky junction significantly reduced charge transfer resistance promoting separation efficiency of excitons as indicated from PL and EIS analysis. The potential of MCNRBO towards photocatalytic application was investigated by H2O2 and H2 evolution reaction. A superior photocatalytic H2O2 and H2 production rate for MCNRBO is observed, which are respectively around 5 and 18 folds higher as compared to pristine CNR nanorod. The present work encourages for the development of a noble, eco-benign and immensely efficient dual heterojunction based photocatalyst, which can acts as saviour of human society from energy crisis.

9.
Nanotechnology ; 35(34)2024 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-38806005

RESUMEN

This study investigated the hydrophobic-hydrophilic characteristics of zinc oxide (ZnO) nanorod coatings for potential biomedical applications. We examined the effects of different alignments of ZnO nanorods on the wetting and mechanical characteristics of the coatings. ZnO seed layers were prepared on stainless-steel plates using atomic layer deposition (ALD) at five different temperatures ranging from 50 to 250 °C. The ZnO nanorod coatings were then deposited on these seed layers through chemical bath deposition. The polycrystalline structure of the seed layers and the morphology of the nanorods were analyzed using grazing incidence angle x-ray diffraction, transmission electron microscopy, and scanning electron microscopy. Mechanical and wetting properties of the nanorod coatings were examined using nanoindentation and water-droplet tests. The seed layers produced at 50 and 250 °C showed stronger (0 0 2) peaks than the other layers. ZnO nanorods on these seed layers exhibited greater vertical orientation and lower water contact angles indicating a more hydrophilic surface. Additionally, vertically oriented nanorod coatings demonstrated greater elastic modulus and hardness than those of oblique nanorods. Our findings indicate that ALD technology can be used to control the spatial arrangement of ZnO nanorods and optimize the hydrophobic-hydrophilic and mechanical properties of coating surfaces.

10.
Nanotechnology ; 35(15)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38176072

RESUMEN

Semiconductor photocatalysis holds significant promise in addressing both environmental and energy challenges. However, a major hurdle in photocatalytic processes remains the efficient separation of photoinduced charge carriers. In this study, TiO2nanorod arrays were employed by glancing angle deposition technique, onto which Ti3C2TxMXene was deposited through a spin-coating process. This hybrid approach aims to amplify the photocatalytic efficacy of TiO2nanorod arrays. Through photocurrent efficiency characterization testing, an optimal loading of TiO2/Ti3C2Txcomposites is identified. Remarkably, this composite exhibits a 40% increase in photocurrent density in comparison to pristine TiO2. This enhancement is attributed to the exceptional electrical conductivity and expansive specific surface area inherent to Ti3C2TxMXene. These attributes facilitate swift transport of photoinduced electrons, consequently refining the separation and migration of electron-hole pairs. The synergistic TiO2/Ti3C2Txcomposite showcases its potential across various domains including photoelectrochemical water splitting and diverse photocatalytic devices. As such, this composite material stands as a novel and promising entity for advancing photocatalytic applications. This study can offer an innovative approach for designing simple and efficient photocatalytic materials composed of MXene co-catalysts and TiO2for efficient water electrolysis on semiconductors.

11.
Nanotechnology ; 35(32)2024 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-38701764

RESUMEN

Herein, corundum-structured Ga2O3(α-Ga2O3) nanorod array/fluorine-doped SnO2(FTO) structures have been fabricated by hydrothermal and thermal annealing processes with different precursor concentrations from 0.01 to 0.06 M. The diameter and length of the nanorod arrays are much larger with increasing precursor concentrations due to more nucleation sites and precursor ions participating in the reaction procedures. The optical bandgap decreases from 4.75 to 4.47 eV because of the tensile stress relieving with increasing the precursor concentrations. Based on self-powered photoelectrochemical (PEC) photodetectors, the peak responsivity is improved from ∼0.33 mA W-1for 0.06 M to ∼1.51 mA W-1for 0.02 M. Schottky junctions can be formed in PEC cells. More photogenerated carriers can be produced in wider depletion region. From Mott-Schottky plots, the depletion regions become much wider with decreasing the precursor concentrations. Therefore, the enhance responsivity is owing to the wider depletion regions. Due to the reduced possibility of photogenerated holes captured by traps ascribed from fewer green and yellow luminescence defects, smaller charge transfer resistance, and shorter transportation route, the decay time becomes much faster through decreasing the precursor concentrations. Compared with the other self-poweredα-Ga2O3-nanorod-array-based PEC photodetectors, it shows the fastest response time (decay time of 0.005 s/0.026 s) simply modulated by precursor concentrations for the first time without employing complex precursors, seed layers or special device designs. Compared with other high-responsivity monoclinic Ga2O3(ß-Ga2O3) self-powered photodetectors, our devices also show comparable response speed with simple control and design. This work provides the realization of fast-speed self-powered Ga2O3based solar-blind ultraviolet photodetectors by simple modulation processes and design, which is a significant guidance for their applications in warnings, imaging, computing, communication and logic circuit, in the future.

12.
Sensors (Basel) ; 24(7)2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38610323

RESUMEN

The mature processes of metal oxide semiconductors (MOS) have attracted considerable interest. However, the low sensitivity of metal oxide semiconductor gas sensors is still challenging, and constrains its practical applications. Bimetallic nanoparticles are of interest owing to their excellent catalytic properties. This excellent feature of bimetallic nanoparticles can solve the problems existing in MOS gas sensors, such as the low response, high operating temperature and slow response time. To enhance acetone sensing performance, we successfully synthesized Au-Pd/ZnO nanorods. In this work, we discovered that Au-Pd nanoparticles modified on ZnO nanorods can remarkably enhance sensor response. The Au-Pd/ZnO gas sensor has long-term stability and an excellent response/recovery process. This excellent sensing performance is attributed to the synergistic catalytic effect of bimetallic AuPd nanoparticles. Moreover, the electronic and chemical sensitization of noble metals also makes a great contribution. This work presents a simple method for preparing Au-Pd/ZnO nanorods and provides a new solution for the detection of acetone based on metal oxide semiconductor.

13.
Nano Lett ; 23(9): 3929-3938, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37129144

RESUMEN

Manufacturing heteronanostructures with specific physicochemical characteristics and tightly controllable designs is very appealing. Herein, we reported NIR-II light-driven dual plasmonic (AuNR-SiO2-Cu7S4) antimicrobial nanomotors with an intended Janus configuration through the overgrowth of copper-rich Cu7S4 nanocrystals at only one high-curvature site of Au nanorods (Au NRs). These nanomotors were applied for photoacoustic imaging (PAI)-guided synergistic photothermal and photocatalytic treatment of bacterial infections. Both the photothermal performance and photocatalytic activity of the nanomotors are dramatically improved owing to the strong plasmon coupling between Au NRs and the Cu7S4 component and enhanced energy transfer. The motion behavior of nanomotors promotes transdermal penetration and enhances the matter-bacteria interaction. More importantly, the directional navigation and synergistic antimicrobial activity of the nanomotors could be synchronously driven by NIR-II light. The marriage of active motion and enhanced antibacterial activity resulted in the expected good antibacterial effects in an abscess infection mouse model.


Asunto(s)
Nanopartículas , Nanotubos , Animales , Ratones , Dióxido de Silicio , Fototerapia , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Oro/uso terapéutico , Oro/química
14.
Int J Mol Sci ; 25(4)2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38396695

RESUMEN

In recent years, gold nanomaterials have become a hot topic in photothermal tumor therapy due to their unique surface plasmon resonance characteristics. The effectiveness of photothermal therapy is highly dependent on the shape and size of gold nanoparticles. In this work, we investigate the photothermal therapeutic effects of four different sizes of gold nanorods (GNRs). The results show that the uptake of short GNRs with aspect ratios 3.3-3.5 by cells is higher than that of GNRs with aspect ratios 4-5.5. Using a laser with single pulse energy as low as 28 pJ laser for 20 s can induce the death of liver cancer cells co-cultured with short GNRs. Long GNRs required twice the energy to achieve the same therapeutic effect. The dual-temperature model is used to simulate the photothermal response of intracellular clusters irradiated by a laser. It is found that small GNRs are easier to compact because of their morphological characteristics, and the electromagnetic coupling between GNRs is better, which increases the internal field enhancement, resulting in higher local temperature. Compared with a single GNR, GNR clusters are less dependent on polarization and wavelength, which is more conducive to the flexible selection of excitation laser sources.


Asunto(s)
Hipertermia Inducida , Nanopartículas del Metal , Nanotubos , Terapia Fototérmica , Oro/farmacología , Hipertermia Inducida/métodos , Nanopartículas del Metal/uso terapéutico
15.
J Environ Sci (China) ; 139: 569-588, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38105077

RESUMEN

Environmental pollution, such as water contamination, is a critical issue that must be absolutely addressed. Here, three different morphologies of tungsten-based photocatalysts (WO3 nanorods, WO3/WS2 nanobricks, WO3/WS2 nanorods) are made using a simple hydrothermal method by changing the solvents (H2O, DMF, aqueous HCl solution). The as-prepared nanocatalysts have excellent thermal stability, large porosity, and high hydrophilicity. The results show all materials have good photocatalytic activity in aqueous media, with WO3/WS2 nanorods (NRs) having the best activity in the photodegradation of bisphenol A (BPA) under visible-light irradiation. This may originate from increased migration of charge carriers and effective prevention of electron‒hole recombination in WO3/WS2 NRs, whereby this photocatalyst is able to generate more reactive •OH and •O2- species, leading to greater photocatalytic activity. About 99.6% of BPA is photodegraded within 60 min when using 1.5 g/L WO3/WS2 NRs and 5.0 mg/L BPA at pH 7.0. Additionally, the optimal conditions (pH, catalyst dosage, initial BPA concentration) for WO3/WS2 NRs are also elaborately investigated. These rod-like heterostructures are expressed as potential catalysts with excellent photostability, efficient reusability, and highly active effectivity in different types of water. In particular, the removal efficiency of BPA by WO3/WS2 NRs reduces by only 1.5% after five recycling runs and even reaches 89.1% in contaminated lake water. This study provides promising insights for the nearly complete removal of BPA from wastewater or different water resources, which is advantageous to various applications in environmental remediation.


Asunto(s)
Luz , Tungsteno , Tungsteno/química , Compuestos de Bencidrilo/química , Agua , Catálisis
16.
J Environ Sci (China) ; 141: 287-303, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38408829

RESUMEN

Graphitic carbon nitride with nanorod structure (Nr-GCN) was synthesized using melamine as a precursor without any other reagents by hydrothermal pretreatment method. XRD, FTIR, SEM, N2 adsorption-desorption from BET, UV-Vis DRS spectroscopy, and photoluminescence were used to characterize the prepared samples. Also, the photoelectrochemical behavior of nanoparticles was studied by photocurrent transient response and cyclic voltammetry analysis. Polystyrene (PS) fibrous mat was fabricated by electrospinning technique and used as a support for the stabilization of the nanoparticles. The performance of the synthesized nanoparticles and photocatalytic fibers (PS/Nr-GCN) was evaluated in oilfield-produced water treatment under visible light irradiation. During this process, oil contaminants were adsorbed by hydrophobic polystyrene fibers and simultaneously degraded by Nr-GCN. The removal efficiency of chemical oxygen demand (COD) has been obtained 96.6% and 98.4% by Nr-GCN and PS/Nr-GCN, respectively, at the optimum conditions of pH 4, photocatalyst dosage 0.5 g/L, COD initial concentration 550 mg/L, and illumination time 150 min. The gas chromatography-mass spectroscopy analysis results showed 99.3% removal of total petroleum hydrocarbons using photocatalytic fibers of PS/Nr-GCN. The results demonstrated that the GCN has outstanding features like controllable morphology, visible-light-driven, and showing high potential in oily wastewater remediation. Moreover, the synergistic effect of adsorption and photocatalytic degradation is an effective technique in oilfield-produced water treatment.


Asunto(s)
Grafito , Nanotubos , Compuestos de Nitrógeno , Poliestirenos , Adsorción , Yacimiento de Petróleo y Gas
17.
Angew Chem Int Ed Engl ; : e202408412, 2024 May 27.
Artículo en Inglés | MEDLINE | ID: mdl-38801019

RESUMEN

The practical application of the electrocatalytic CO2 reduction reaction (CO2RR) to form formic acid fuel is hindered by the limited activation of CO2 molecules and the lack of universal feasibility across different pH levels. Herein, we report a doping-engineered bismuth sulfide pre-catalyst (BiS-1) that S is partially retained after electrochemical reconstruction into metallic Bi for CO2RR to formate/formic acid with ultrahigh performance across a wide pH range. The best BiS-1 maintains a Faraday efficiency (FE) of ~95 % at 2000 mA cm-2 in a flow cell under neutral and alkaline solutions. Furthermore, the BiS-1 catalyst shows unprecedentedly high FE (~95 %) with current densities from 100 to 1300 mA cm-2 under acidic solutions. Notably, the current density can reach 700 mA cm-2 while maintaining a FE of above 90 % in a membrane electrode assembly electrolyzer and operate stably for 150 h at 200 mA cm-2. In situ spectra and density functional theory calculations reveals that the S doping modulates the electronic structure of Bi and effectively promotes the formation of the HCOO* intermediate for formate/formic acid generation. This work develops the efficient and stable electrocatalysts for sustainable formate/formic acid production.

18.
Small ; 19(10): e2207743, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36683224

RESUMEN

Electrochemical nitrate (NO3 - ) reduction to ammonia (NH3 ) offers a promising pathway to recover NO3 - pollutants from industrial wastewater that can balance the nitrogen cycle and sustainable green NH3 production. However, the efficiency of electrocatalytic NO3 - reduction to NH3 synthesis remains low for most of electrocatalysts due to complex reaction processes and severe hydrogen precipitation reaction. Herein, high performance of nitrate reduction reaction (NO3 - RR) is demonstrated on self-supported Pd nanorod arrays in porous nickel framework foam (Pd/NF). It provides a lot of active sites for H* adsorption and NO3 - activation leading to a remarkable NH3 yield rate of 1.52 mmol cm-2  h-1 and a Faradaic efficiency of 78% at -1.4 V versus RHE. Notably, it maintains a high NH3 yield rate over 50 cycles in 25 h showing good stability. Remarkably, large-area Pd/NF electrode (25 cm2 ) shows a NH3 yield of 174.25 mg h-1 , be promising candidate for large-area device for industrial application. In situ FTIR spectroscopy and density functional theory calculations analysis confirm that the enrichment effect of Pd nanorods encourages the adsorption of H species for ammonia synthesis following a hydrogenation mechanism. This work brings a useful strategy for designing NO3 - RR catalysts of nanorod arrays with customizable compositions.

19.
Small ; 19(2): e2200712, 2023 01.
Artículo en Inglés | MEDLINE | ID: mdl-36385593

RESUMEN

Rapid spread of infectious diseases is a global threat and has an adverse impact on human health, livelihood, and economic stability, as manifested in the ongoing coronavirus disease 2019 (COVID-19) pandemic. Even though people wear a face mask as protective equipment, direct disinfection of the pathogens is barely feasible, which thereby urges the development of biocidal agents. Meanwhile, repetitive respiration generates temperature variation wherein the heat is regrettably wasted. Herein, a biocidal ZnO nanorod-modified paper (ZNR-paper) composite that is 1) integrated on a face mask, 2) harvests waste breathing-driven thermal energy, 3) facilitates the pyrocatalytic production of reactive oxygen species (ROS), and ultimately 4) exhibits antibacterial and antiviral performance is proposed. Furthermore, in situ generated compressive/tensile strain of the composite by being attached to a curved mask is investigated for high pyroelectricity. The anisotropic ZNR distortion in the bent composite is verified with changes in ZnO bond lengths and OZnO bond angles in a ZnO4 tetrahedron, resulting in an increased polarization state and possibly contributing to the following pyroelectricity. The enhanced pyroelectric behavior is demonstrated by efficient ROS production and notable bioprotection. This study exploring the pre-strain effect on the pyroelectricity of ZNR-paper might provide new insights into the piezo-/pyroelectric material-based applications.


Asunto(s)
COVID-19 , Óxido de Zinc , Humanos , COVID-19/prevención & control , Óxido de Zinc/química , Máscaras , Especies Reactivas de Oxígeno , Respiración
20.
Chemistry ; 29(44): e202300955, 2023 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-37212621

RESUMEN

The grafting region of polymeric ligands exhibit a significant influence on the assembly behavior of polymer tethered gold nanorods (AuNRs) in confined space. In this work, the effect of core size, molecular weight and grafting region of ligands on the assembly structure in cylindrical nanopores was investigated. It is found that polystyrene end-tethered AuNR (AuNR@End-PS) exhibits a dumbbell-like shape, while the AuNR with PS tethered on the entire surface (AuNR@Full-PS) shows a rod-like morphology that gradually transforms into a spherical shape as the molecular weight increases. AuNR@End-PS is affected by the special steric hindrance at both ends, and prefers to form special structures such as inclination arrangement, whereas AuNR@Full-PS prefers to be arranged shoulder-to-shoulder in a chain-like assembly. The confinement effect was studied as well by varying the diameter of pores. The results show that the nanoparticles prefer to arrange into a regular and ordered assembly structure in the strong confinement spaces. Under the synergy of confined spaces and ligands at both ends, the AuNRs@End-PS are more likely to form a tilted order-assembly structure. The results of this work could provide new ideas and guidance for the preparation of ordered assembly of AuNRs with novel structures.

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