Nanotechnology最新文献

{"title":"The measurement of phenols with graphitic carbon fiber microelectrodes and fast-scan cyclic voltammetry.","authors":"Cam Abdullaeva, Nadiah Alyamni, Jackie Jessen-Hegelbach, Alexander G Zestos","doi":"10.1088/1361-6528/ada299","DOIUrl":"https://doi.org/10.1088/1361-6528/ada299","url":null,"abstract":"<p><p>A phenol contains a six-membered, conjugated, aromatic ring that is bound to a hydroxyl group. These molecules are important in biomedical studies, aromatic food preparation, and petroleum engineering. Traditionally, phenols have been measured with several analytical techniques such as UV-VIS spectroscopy, fluorescence, liquid chromatography, and mass spectrometry. These assays provide for relatively high sensitivity and selectivity measurements, but they suffer from relatively low spatiotemporal resolution, low biocompatibility, long analysis time, high cost, and complex sample treatment. Recently, electrochemistry has served as a viable alternative to the measurement of phenols. In this study, we utilized carbon fiber microelectrodes (CFMEs) with fast-scan cyclic voltammetry (FSCV) for the sensitive and selective measurement of phenols. We tested four common phenolic compounds: phenol, 2-methylaminophenol (2-MAP), 4-methylaminophenol (4-MAP), and 3-hydroxybenzoic acid (3-HBA). We found that phenol, 2-MAP, 4-MAP, and 3-HBA were all partially adsorption and diffusion controlled to the surface of the CFMEs and that all four molecules could be detected with repeated injections. Structural differences between the phenols led to varied sensitivities amongst the four phenols, and we were able to co-detect and differentiate the phenols in complex solutions with dopamine and serotonin. Lastly, we measured the phenols in simulated urine with a high percent recovery. These assays demonstrate enhanced electrochemical measurement of phenols, which will create more effective diagnostics for these complex molecules to help elucidate their mechanistic properties and ultimate significance.&#xD.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142882323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unveiling the phases of bulk ZrTe₅through magnetotransport phenomena.","authors":"Pi-Ju Shih, Cheng-Hsueh Yang, Pin-Chi Liao, Wei-Chen Lin, Fa-Hua Chen, Jeng-Chung Chen, Limin Cao, Chiashain Chuang, Chi-Te Liang","doi":"10.1088/1361-6528/ad9d48","DOIUrl":"10.1088/1361-6528/ad9d48","url":null,"abstract":"<p><p>We present a straightforward method which may greatly simplify and lower the threshold for determining the phase of the relatively enigmatic quantum material-ZrTe₅. In this study, without directly probing the band structure, we identify the topological phase of the three-dimensional (3D) bulk ZrTe₅crystal solely through low-temperature electrical and magnetotransport measurements. A two-dimensional (2D) weak antilocalization (WAL) effect was observed in our bulk ZrTe₅crystal, along with clear Shubnikov-de Haas oscillations. The large prefactorαderived from WAL analyses indicates the presence of multiple conducting channels in the bulk ZrTe₅crystal, where each channel is associated with individual 2D ZrTe₅layers. It is the largeαvalue provides insights into the topological Dirac semimetal phase inherent to our ZrTe₅crystal. Additionally, we analyze the pronounced linear magnetoresistance and saturation behavior under a perpendicular magnetic field. Our results suggest that bulk ZrTe₅crystals, which exhibit unique layered transport features, serve as a promising platform for further research in quantum phases and transitions in 3D quantum systems.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142813710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth and properties of hybrid Au-Co_0.8Ni_0.2nanowires embedded in SrTiO₃/SrTiO₃(001).","authors":"T Tran, M Hennes, D Demaille, B Gallas, G Patriarche, D Hrabovsky, A Coati, A Vlad, A Resta, M Sauvage-Simkin, Y Garreau, Y Zheng, F Vidal","doi":"10.1088/1361-6528/ad9df1","DOIUrl":"10.1088/1361-6528/ad9df1","url":null,"abstract":"<p><p>We present a sequential growth scheme based on pulsed laser deposition, which yields dense arrays of ultrathin, match-shaped Au/CoNi nanopillars, vertically embedded in SrTiO₃thin films. Analysis of the magnetic properties of these nanocomposites reveals a pronounced out-of-plane anisotropy. We show that the latter not only results from the peculiar nanoarchitecture of the hybrid films but is further enhanced by strong magneto-structural coupling of the wires to the surrounding matrix. Finally, we provide a detailed overview of the optical response of these vertical nanostructures. Combining ellipsometry measurements with finite-difference time-domain simulations allows us to assess the potential of our self-assembly approach, as well as its possible shortcomings, for producing hybrid thin films with well-tailored magneto-plasmonic properties.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142818780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passivation of acceptors in GaN by hydrogen and their activation.","authors":"Michael A Reshchikov, Oleksandr Andrieiev, Mykhailo Vorobiov, Dexian Ye, Denis O Demchenko, Benjamin McEwen, Shadi Shahedipour-Sandvik","doi":"10.1088/1361-6528/ada298","DOIUrl":"https://doi.org/10.1088/1361-6528/ada298","url":null,"abstract":"<p><p>GaN is an important semiconductor for energy-efficient light-emitting devices. Hydrogen plays a crucial role in gallium nitride (GaN) growth and processing. It can form electrically neutral complexes with acceptors during growth, which significantly increases the acceptor incorporation. Post-growth annealing dissociates these complexes and is widely utilized for activating Mg acceptors and achieving conductive p-type GaN. In this work, we demonstrate that other acceptors, such as C and Be, also form complexes with hydrogen similar to Mg. The effect of thermal annealing of GaN on photoluminescence (PL) was investigated. In samples moderately doped with Be, the BeGa-related yellow luminescence (YLBe) band intensity decreased by up to an order of magnitude after annealing in N2 ambient at temperatures Tann = 400900 °C. This was explained by the release of hydrogen from unknown traps and the passivation of the BeGa acceptors. A similar drop of PL intensity at Tann = 350900 °C was observed for the CN-related YL1 band in unintentionally C-doped GaN and also attributed to passivation of the CN acceptors by hydrogen released from unknown defects. In this case, the formation of the CNHi complexes was confirmed by the observation of the rising BL2 band associated with these complexes. At Tann > 900 °C, both the YLBe and YL1 intensities were restored, which was explained by the removal of hydrogen from the samples. Experimental results were compared to the first principles calculations of complex dissociation and hydrogen diffusion paths in GaN.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142882317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastic limit and relaxation of GaAs/In(Al,Ga)As core/shell nanowires for near-infrared applications.","authors":"Polyxeni Chatzopoulou, Donovan Hilliard, Isaak G Vasileiadis, Nikoletta Florini, Vivek Devulapalli, Christian H Liebscher, Liverios Lymperakis, Philomela Komninou, Thomas Kehagias, Emmanouil Dimakis, George P Dimitrakopulos","doi":"10.1088/1361-6528/ad9d4a","DOIUrl":"10.1088/1361-6528/ad9d4a","url":null,"abstract":"<p><p>In the GaAs/In<i>_x</i>(Al,Ga)_1-<i>x</i>As core/shell nanowire (CSNW) geometry, narrow cores exhibit significant bandgap reduction and enhanced electron mobility because of their ability to sustain extreme tensile elastic strain. In such an elastic state, the coherency limits and the resulting physical properties of the nanowires are governed by the strain field distribution and plastic relaxation mechanisms. Using atomic-resolution transmission electron microscopy, we determined the three-dimensional strain field, critical misfit, and plastic relaxation relative to the indium content of the shell, while maintaining constant core-shell dimensions. The strain was mapped experimentally in both coherent and plastically relaxed nanowires with a core radius of 10 nm and thick shells and was compared to atomistic and continuum calculations. Our findings reveal that, while axial strains remain uniform, elastic relaxation induces radial and tangential strain gradients. This is attributed to the strain concentration at the sharp interfaces, which persisted even after plastic relaxation. For the pertinent growth conditions, the maximum sustained elastic strain in the cores was observed for the GaAs/In_0.5Al_0.5As nanowires. The plastic relaxation of nanowires with shells of high indium content involved Frank partials delimiting horizontal intrinsic stacking faults (SFs), misfit dislocations gliding on inclined close-packed planes, and stair-rod dislocations along SF junction lines attributed to nanowire bending.<i>Ab initio</i>calculations showed that the heterojunction remained type I even for the highest elastic strain, despite the existence of strain gradients at the core-shell interface. Our results elucidate the elastoplastic behaviour of CSNWs with narrow cores, offering new perspectives on growth strategies to further push their coherency limits.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142813706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elimination of antibiotic contaminants from wastewater using polycarbazole nanocomposites as microwave-activated catalysts.","authors":"Jannatun Zia, Noushi Zaidi, Sapana Jadoun, Ufana Riaz","doi":"10.1088/1361-6528/ada1dd","DOIUrl":"https://doi.org/10.1088/1361-6528/ada1dd","url":null,"abstract":"<p><p>Ciprofloxacin (CIP) is a widely used antibiotic, and its presence in water bodies poses a risk due to its resistance to conventional wastewater treatment processes. The accumulation of such pharmaceuticals can disrupt aquatic ecosystems, harm aquatic life, and contribute to ecological imbalances. Therefore, the degradation of CIP is of immense environmental significance. This study presents the microwave-assisted catalytic degradation of the antibiotic drug Ciprofloxacin (CIP) using nanocomposites of carbazole copolymerized with pyrrole (PCz-co-PPy) and with thiophene (PCz-co-PTh). The PCz-co-PPy and PCz-co-PTh nanocomposites were synthesized through an ultrasound-assisted method. The resulting nanocomposites were characterized using spectral and morphological analyses. FT-IR and UV-Vis spectroscopy confirmed successful intercalation and copolymerization, while FESEM images revealed a chain-like morphology. These copolymer nanocomposites were employed as microwave-active catalysts for CIP degradation, achieving an optimal degradation efficiency of 95% within 21 minutes using PCz-co-PPy-50/50 and PCz-co-PTh-50/50 at 600W microwave power. The degradation followed pseudo-first-order kinetics, with rate constants calculated as 0.031 min⁻¹, 0.020 min⁻¹, 0.030 min⁻¹, 0.056 min⁻¹, and 0.071 min⁻¹ for PCz, PPy, PTh, PCz-co-PPy-50/50, and PCz-co-PTh-50/50 nanocomposites, respectively, for a 50 mg/L CIP solution. The catalytic efficiency is attributed to the formation of microwave-induced active species, including hot spots, electrons (e⁻), holes (h⁺), superoxide radicals (•O₂⁻), and hydroxyl radicals (•OH). Scavenger analysis verified that •OH and •O₂⁻ radicals play a crucial role in CIP degradation. A possible degradation mechanism and pathway for the nanocomposite system is proposed.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142869674","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Accurate computation of gas binding in the nanoscale porous organic cage CC3 via coupled cluster theory.","authors":"Ka Un Lao","doi":"10.1088/1361-6528/ad9b33","DOIUrl":"10.1088/1361-6528/ad9b33","url":null,"abstract":"<p><p>This study investigates the binding of seven gas molecules-N₂, CH₄, C₂H₂, CO₂, H₂O, SF₆, and CHCl₃-within the central cavity of the nanoscale porous organic cage CC3, using a high-level local coupled cluster method that accounts for single, double, and perturbative triple excitations, extrapolated to the complete basis set limit. This results in the formation of the CC3@7 dataset, which presents unique challenges due to the need for accurate descriptions of confinement effects and many-body interactions that contribute to binding. The CC3@7 dataset is used to evaluate a variety of lower-cost computational approaches. Among the methods tested for accurately predicting the binding order for all seven gas molecules, the recommended MP2-based approach is MP2+<i>ai</i>D(CCD), which achieves a mean absolute error (MAE) of 0.4 kcal mol^-1. For density functional theory (DFT) methods, B97M-V+<i>E</i>^ABC, B97M-V, M06-L-D3, B97M-rV+<i>E</i>^ABC, PBE0+D4, and PBE+D4 are recommended, with MAEs ranging from 0.3 to 0.4 kcal mol^-1. Additionally, r²SCAN-3c and<i>ω</i>B97X-3c are identified as low-cost options, with MAEs of approximately 1 kcal mol^-1. Considering both accuracy and stability, PBE0+D4 is recommended for investigating nanoscale host-guest bindings when only DFT methods are feasible. Furthermore, PBE0+D4 has been successfully applied to study the binding of additional atoms and hindered solvent molecules, demonstrating the flexibility of the CC3 cage to accommodate larger molecules that exceed its cavity size.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Mn²⁺ions and TOP molecules on the luminescence properties of oleic acid caped CsPbI₃nanocrystals.","authors":"Xiaozong Huang, Wen Li, Linghang Kong, Xiaoyan Lu, Chengzhi Yang, Bingsuo Zou","doi":"10.1088/1361-6528/ad9c81","DOIUrl":"10.1088/1361-6528/ad9c81","url":null,"abstract":"<p><p>Due to the easy transformation to the non-luminous yellow<i>δ</i>-CsPbI₃phase in air,<i>α</i>-CsPbI₃nanocrystalline materials with red light emission find limited applications. Lifting its structural stability is a challenge in its quantum dot (QD) lighting field. Here we studied the doping of Mn²⁺ions (5.0%) and processing by a small amount (0.315 ml) of TOP molecules on the OA-capped CsPbI₃nanocrystals. It is found that after the successful introduction of Mn²⁺into the CsPbI₃nanocrystal, the grain size reduces, which leads to a stronger quantum confinement effect than the undoped QDs, which leads to the blue shift of PL and absorption spectra. The incorporation of Mn²⁺simultaneously reduced defects and lifted the luminescence efficiency and lifetimes of QDs, the cause for the above optical behavior is due to the formation of excitonic magnetic polaron (EMP) excitons near the bandedge. On the other hand, the treated TOP molecule on the OA-capped NCs did not significantly affect their room-temperature luminescence. However, it improved the low-temperature emission performances of QDs significantly. Moreover, the TOP-treated QDs fixed in the PMMA film can transform into rod-like shapes in acidic environments, giving strong stability for emission, especially for the Mn-doped CsPbI₃QDs. This work has been done to improve the stability and emission efficiency of related QDs through the EMP formation near band-edge and surface modification of CsPbI₃NCs, favoring their potential applications in display and low-temperature light-emitting devices.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142829454","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"HF-free low temperature synthesis of MXene for electrochemical hydrogen production.","authors":"Ranjit D Mohili, Kajal Mahabari, Monika Patel, N R Hemanth, Arvind Jadhav, Kwangyeol Lee, Nitin Chaudhari","doi":"10.1088/1361-6528/ada1de","DOIUrl":"https://doi.org/10.1088/1361-6528/ada1de","url":null,"abstract":"<p><p>MXenes (two-dimensional (2D) transition-metal carbides, nitrides, and carbonitrides) are gaining significant interest as alternative electrocatalysts for the hydrogen evolution reaction due to their excellent properties, such as high electrical conductivity, large surface area, and chemical stability. MXenes are traditionally synthesized using hydrofluoric acid (HF), which raises safety and environmental concerns due to its highly corrosive and toxic nature. HF introduces fluoride functional groups on the surface of MXenes, which have been reported to have a detrimental effect on electrocatalysis. As a result, there is growing interest in developing MXenes through non-fluoride routes. Here, we report a room-temperature, HF-free, wet-chemical synthesis of MXene using a hydrogen peroxide and chromium chloride mixture. The newly prepared CH-MXenes possess hydrophilic functionalities (-Cl, -OH, and =O). Key advantages of the CH-route over HF-based synthesis include the elimination of an additional delamination step, the prevention of MXene restacking via chloride functionalities, and the consistent production of high-quality 2D MXenes with a reproducible flake size (~650 nm). These CH-MXenes exhibit high surface area, excellent conductivity, and enhanced chemical stability, making them suitable for various energy and other applications.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142869626","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editorial for focus on emerging processes and applications of atomic and molecular layer deposition.","authors":"Xiangbo Meng, Jeffrey W Elam, Sean Barry","doi":"10.1088/1361-6528/ad9d4b","DOIUrl":"10.1088/1361-6528/ad9d4b","url":null,"abstract":"<p><p>This Focus aims to provide a platform for the latest research progress in atomic and molecular layer deposition (ALD and MLD), which collects 10 original research articles and 2 review papers. The original research articles present new precursors, new processes, and new applications. The review papers give a timely summary on the surface chemistry of metal ALD processes and flexible electronics resulting from ALD and MLD, respectively. This ensemble forms a valuable collection that advances our understanding and knowledge of ALD and MLD, and inspires the continued development of these valuable technologies.</p>","PeriodicalId":19035,"journal":{"name":"Nanotechnology","volume":" ","pages":""},"PeriodicalIF":2.9,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142813705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}