| 1. |
- Abal, Joao P. K., et al.
(författare)
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Molecular Dynamics Simulations of Water Anchored in Multilayered Nanoporous MoS2 Membranes : Implications for Desalination
- 2021
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 4:10, s. 10467-10476
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Tidskriftsartikel (refereegranskat)abstract
- One of the most promising applications in nano-science is the design of new materials to improve water permeability and selectivity of nanoporous membranes. Understanding the molecular architecture behind these fascinating structures and how it impacts the water flow is an intricate but a necessary task. We studied here the water flux through multi-layered nanoporous molybdenum disulfide (MLNMoS2) membranes with different nanopore sizes and lengths. Molecular dynamics simulations show that the permeability does not increase with the inverse of the membrane thickness, violating the classical hydrodynamic behavior. The data also reveal that water dynamics is slower than those observed in frictionless carbon nanotubes and multilayer graphene membranes, which we explain in terms of an anchor mechanism observed in between layers. We show that the membrane permeability is critically dependent on the nanopore architecture, bringing important insights into the manufacture of new desalination membranes.
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| 2. |
- Abbondanza, Giuseppe, 1991, et al.
(författare)
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Au-Pd Barcode Nanowires with Tailored Lattice Parameters and Segment Lengths for Catalytic Applications
- 2024
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Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 7:4, s. 3861-3874
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we present a systematic investigation of the controlled fabrication of Au-Pd barcode nanowires within nanoporous anodic aluminum oxide (NP-AAO) templates. By using a combination of in situ X-ray diffraction (XRD), focused ion beam scanning electron microscopy (FIB-SEM), and transmission electron microscopy (TEM), we elucidate the influence of template preparation methods on the resulting nanowire properties. The template treatment, involving either pore widening or barrier layer thinning, significantly impacts nanowire growth. Through the analysis of the XRD data, we observe sequential deposition of Au and Pd segments with lattice parameter variations and strain effects. Particularly, the lattice parameters of Au and Pd segments display intricate temporal dependencies, influenced by interfacial effects and strain caused by growth under confinement. FIB-SEM imaging reveals uniform and reproducible nanowire lengths in the template treated with pore widening. Furthermore, TEM analysis confirms the presence of distinct Au and Pd segments, while scanning TEM-energy-dispersive X-ray spectroscopy revealed minor evidence of interdiffusion between the first and the second electrodeposited segments. Our findings emphasize the potential of the electrodeposition process within nanoporous templates for producing barcode nanowires with precise segmental properties. The combination of in situ XRD and electron microscopy offers valuable insights into the growth dynamics and structural characteristics of the fabricated Au-Pd barcode nanowires. This controlled fabrication strategy opens doors to tailoring nanowire properties for diverse applications, particularly in catalysis.
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| 3. |
- Adeniyi, Omotayo, et al.
(författare)
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Solution-processable bismuthene nanosheets for ultrasensitive sensing of heavy metal ions via anodic stripping voltammetry
- 2024
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970.
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Tidskriftsartikel (refereegranskat)abstract
- Bismuthene, a two-dimensional nanostructured material derived from the environmentally friendly and nontoxic element bismuth, holds significant potential for sustainable electrocatalytic applications. However, the large-scale application of bismuthene is hindered by the absence of a high-throughput method for synthesizing solution-processable bismuthene nanosheets, which are essential for the straightforward and low-cost fabrication of bismuthene-based nanostructure devices. This study introduces a simple solvothermal method for synthesizing bismuthene nanosheets, using hexamethylenetetramine (HMTA) as a structure-directing agent and in situ-generated hydrogen (H2) from the alkaline hydrolysis of NaBH4 as the reducing agent. The structural and electron transfer properties were characterized by using microscopic, spectroscopic, and electrochemical analyses. To demonstrate the electrocatalytic application potential, a bismuthene-modified screen-printed carbon nanotube electrode was fabricated as a nanosensor for the quantitative detection of heavy metal ions in contaminated water. The nanosensor exhibited a wide linear concentration range and low detection limits of 0.1 and 0.16 ppb (μg/L) for Cd and Pb, respectively. Additionally, the sensor was integrated with a microfluidic flow cell, demonstrating its applicability for the flow-through analysis of Cd and Pb ions. The nanosensor showed high selectivity for Cd and Pb ions in the presence of other metal ions with excellent repeatability and sensor-to-sensor reproducibility, evidenced by a relative standard deviation of 2% and 10%, respectively.
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| 4. |
- Aggarwal, Ruchi, et al.
(författare)
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Cellulose-Derived Carbon Dots for Inner Filter Effect-Based Selective Sensing of Ofloxacin Antibiotics
- 2023
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Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 6:8, s. 6518-6527
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Tidskriftsartikel (refereegranskat)abstract
- A two-step viable synthetic approach for quick and energy-efficient acid-based charring is described here to fabricate self-passivated fluorescent water-soluble CD (wsCD) from sustainable microcrystalline cellulose (MCC) materials. The aqueous solution of wsCD exhibits blue emission under UV-light illumination and shows a fluorescence quantum yield of ∼6%. The wsCD are used here for the selective sensing of ofloxacin (OFLX) from among the four tested antibiotics of the fluoroquinolone class, namely, ciprofloxacin (CPLX), ofloxacin (OFLX), levofloxacin (LVLX), and moxifloxacin (MXLX) based on the simpler fluorescence quenching experiment with a detection limit of ∼0.025 ppm. The plausible mechanism for the selective sensing of OFLX has been proposed based on a detailed analysis of absorbance and time-resolved photoluminescence spectroscopy which indicates the involvement of the inner-filter effect (IFE). Antimicrobial studies of wsCD were conducted on two bacterial strains (Escherichia coli and Staphylococcus aureus) and two fungal strains (Aspergillus niger and Penicillium chrysogenum), where wsCD did not show any toxic effects up to the concentration of 1 mg/mL, hence supporting their biocompatible behavior. Further, an antibiosis study involving the combination of the antibiotic and antifungal agents with wsCD against the growth of the same bacterial and fungal strains was conducted, where wsCD showed mild antifungal activity.
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| 5. |
- Aggarwal, Ruchi, et al.
(författare)
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Nitrogen-Doped Carbon Nanoflakes by Acidic Charring of Microcrystalline Cellulose and Urea for the Rapid Removal of Imidacloprid from Water
- 2024
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Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 7:1, s. 1-10
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Forskningsöversikt (refereegranskat)abstract
- Herein, cellulose as a natural biomass along with urea was acid-charred to synthesize nitrogen-doped carbon nanoflakes (N-CNF). The as-prepared N-CNF was used to rapidly remove the effluent of agricultural waste containing an Imidacloprid (IMD) insecticide. The adsorption data fit well to nonlinearly in the Sips adsorption model, which is a mixed Langmuir-Freundlich model with an adsorption capacity of ∼104.9 mg g-1. The adsorption follows pseudo-second-order kinetics linearly and nonlinearly, and thermodynamic parameters reveal that the adsorption process was spontaneous and endothermic. The effect of pH and the interference of ions was also checked. Further, spiking of IMD in different soil, lake, and tap wastewater samples was also done to enhance the practical applicability of removing IMD by N-CNF. The antibacterial properties of N-CNF were checked on both Gram-negative and Gram-positive bacterial strains as Escherichia coli and Bacillus subtilus, respectively, where they showed nontoxic behavior up to the concentration of 2 mg mL-1
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| 6. |
- Akbari-Saatlu, Mehdi, et al.
(författare)
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Nanometer-Thick ZnO/SnO2Heterostructures Grown on Alumina for H2S Sensing
- 2022
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 5:5, s. 6954-6963
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Tidskriftsartikel (refereegranskat)abstract
- Designing heterostructure materials at the nanoscale is a well-known method to enhance gas sensing performance. In this study, a mixed solution of zinc chloride and tin (II) chloride dihydrate, dissolved in ethanol solvent, was used as the initial precursor for depositing the sensing layer on alumina substrates using the ultrasonic spray pyrolysis (USP) method. Several ZnO/SnO2 heterostructures were grown by applying different ratios in the initial precursors. These heterostructures were used as active materials for the sensing of H2S gas molecules. The results revealed that an increase in the zinc chloride in the USP precursor alters the H2S sensitivity of the sensor. The optimal working temperature was found to be 450 °C. The sensor, containing 5:1 (ZnCl2: SnCl2·2H2O) ratio in the USP precursor, demonstrates a higher response than the pure SnO2 (∼95 times) sample and other heterostructures. Later, the selectivity of the ZnO/SnO2 heterostructures toward 5 ppm NO2, 200 ppm methanol, and 100 ppm of CH4, acetone, and ethanol was also examined. The gas sensing mechanism of the ZnO/SnO2 was analyzed and the remarkably enhanced gas-sensing performance was mainly attributed to the heterostructure formation between ZnO and SnO2. The synthesized materials were also analyzed by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray, transmission electron microscopy, and X-ray photoelectron spectra to investigate the material distribution, grain size, and material quality of ZnO/SnO2 heterostructures.
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| 7. |
- Alcer, David, et al.
(författare)
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Vertically Processed GaInP/InP Tandem-Junction Nanowire Solar Cells
- 2024
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Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 7:2, s. 2352-2358
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Tidskriftsartikel (refereegranskat)abstract
- We present vertically processed photovoltaic devices based on GaInP/InP tandem-junction III-V nanowires (NWs), contacting approximately 3 million NWs in parallel for each device. The GaInP and InP subcells as well as the connecting Esaki tunnel diode are all realized within the same NW. By processing GaInP/InP tandem-junction NW solar cells with varying compositions of the top junction GaInP material, we investigate the impact of the GaInP composition on the device performance. External quantum efficiency (EQE) measurements on devices with varying GaInP composition provide insights into the performance of the respective subcells, revealing that the GaInP subcell is current-limiting for all devices. I-V measurements under AM1.5G illumination confirm voltage addition of the subcells, resulting in an open-circuit voltage of up to 1.91 V. However, the short-circuit current density is low, ranging between 0.24 and 3.44 mA/cm2, which leads to a resulting solar conversion efficiency of up to 3.60%. Our work shows a path forward toward high-efficiency NW photovoltaics and identifies critical issues that need improvement.
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| 8. |
- Anikina, Ekaterina, et al.
(författare)
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Li-Functionalized Carbon Nanotubes for Hydrogen Storage : Importance of Size Effects
- 2019
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Ingår i: ACS APPLIED NANO MATERIALS. - : AMER CHEMICAL SOC. - 2574-0970. ; 2:5, s. 3021-3030
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Tidskriftsartikel (refereegranskat)abstract
- We investigated Li-doped carbon nanotubes (CNTs) as a promising hydrogen storage media. In this computational model, we considered isolated lithium atom adsorbed on a CNT wall as an adsorption site for hydrogen. We focused on the influence of size effects on the structural and energetic characteristics of CNT(n,n)@Li+kH(2) complexes where n = 5, 7, 9; k = 1,..., 6; N, = 4, 5, 6 (N-c is translation length of CNT, expressed in terms of a number of CNT unit cells). We proved that modeled CNT length substantially influences internal sorption of Li and hydrogen on the narrow tube (5,5), which subsequently alters the adsorption energies of H-2 molecules and causes the deformation of the carbon framework. Moreover, the size effects are not pronounced in the case of external sorption for all considered CNT translation lengths and diameters. We have not observed any noticeable qualitative difference between internal and external hydrogen sorption in the nanotube wider than CNT(5,5). In the case of external adsorption on all considered nanotubes, doping with Li increases hydrogen adsorption energies of up to four H-2 molecules by 100 meV in comparison with pure CNTs. And the local density approximation estimations (similar to 250 meV/H-2) of adsorption energy on Li-decorated CNTs exceed the lowest requirement proposed by the U.S. Department of Energy (200 meV/H-2). In the case of internal sorption on Li-functionalized tubes, the generalized gradient approximation also gives hydrogen adsorption energies in the desired range of 200-600 meV/H-2. However, steric hindrances could prevent sufficient hydrogen uptakes (less than 2 wt % inside CNT(5,5)). We believe that our findings on the size effects are important for estimation of CNT's hydrogen storage properties.
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| 9. |
- Azhar, Muhammad Rizwan, et al.
(författare)
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Electrodeposited Metal Organic Framework toward Excellent Hydrogen Sensing in an Ionic Liquid
- 2020
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Ingår i: ACS APPLIED NANO MATERIALS. - : American Chemical Society (ACS). - 2574-0970. ; 3:5, s. 4376-4385
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of thin films of metal organic frame-works (MOFs) is a rapidly growing area owing to the use of these highly functional nanomaterials for various applications. In this study, a thin layer of a typical MOF, copper benzene tricarboxylate (HKUST-1), was synthesized by electrodeposition on a glassy carbon (GC) electrode using a potential-step chronoamperometric technique at room temperature. Various characterization techniques including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) were used to verify the successful deposition of the MOF film and its structure. The electrodeposited MOF crystals showed cuboctahedral morphology with macropores. The MOF modified electrode was applied for hydrogen gas sensing in a room-temperature ionic liquid (RTIL) for the first time. A 4-fold increase in current was observed compared to a precious metal, that is, platinum, and the electrode exhibited a significant catalytic activity compared to the bare GC electrode, making it a very promising low cost material for hydrogen gas sensing.
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| 10. |
- Betker, Marie, et al.
(författare)
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Sprayed Hybrid Cellulose Nanofibril-Silver Nanowire Transparent Electrodes for Organic Electronic Applications
- 2023
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 6:14, s. 13677-13688
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Tidskriftsartikel (refereegranskat)abstract
- In times of climate change and resource scarcity, researchers are aiming to find sustainable alternatives to synthetic polymers for the fabrication of biodegradable, eco-friendly, and, at the same time, high-performance materials. Nanocomposites have the ability to combine several favorable properties of different materials in a single device. Here, we evaluate the suitability of two kinds of inks containing silver nanowires for the fast, facile, and industrial-relevant fabrication of two different types of cellulose-based silver nanowire electrodes via layer-by-layer spray deposition only. The Type I electrode has a layered structure, which is composed of a network of silver nanowires sprayed on top of a cellulose nanofibrils layer, while the Type II electrode consists of a homogeneous mixture of silver nanowires and cellulose nanofibrils. A correlation between the surface structure, conductivity, and transparency of both types of electrodes is established. We use the Haacke figure of merit for transparent electrode materials to demonstrate the favorable influence of cellulose nanofibrils in the spray ink by identifying Type II as the electrode with the lowest sheet resistance (minimum 5 ± 0.04 Ω/sq), while at the same time having a lower surface roughness and shorter fabrication time than Type I. Finally, we prove the mechanical stability of the Type II electrode by bending tests and its long-time stability under ambient conditions. The results demonstrate that the mixed spray ink of silver nanowires and cellulose nanofibrils is perfectly suitable for the fast fabrication of highly conductive organic nanoelectronics on an industrial scale.
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