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Au@Cu Core-Shell Nanocubes with Controllable Sizes in the Range of 20-30 nm for Applications in Catalysis and Plasmonics
摘要： Predominantly covered by a single type of {100} facets, Cu nanocubes are attractive catalytic material toward reactions such as electrochemical reduction of CO2. Here we report a seed-mediated approach to the facile synthesis of Au@Cu core-shell nanocubes with hexadecylamine and Cl- serving as capping agents toward the {100} facets of Cu and glucose as a reducing agent. The large (12%) lattice mismatch between Cu and Au led to the localized epitaxial growth of Cu shells on the Au seeds and the formation of nanocubes with randomly distributed Au cores. Compared to the same synthesis in the absence of Au seeds, the reduction of Cu(II) ions was greatly accelerated in the presence of Au seeds because of the autocatalytic surface reduction. It was also found that the structure and morphology of the products were highly dependent on the concentration of Cu(II) precursor in the reaction solution. Nanoplates rather than nanocubes were obtained when the concentration of Cu(II) precursor was reduced down to a certain level. By varying the reaction time and/or the amount of Au seeds, the size of the Au@Cu nanocubes could be tuned in a range of 20–30 nm. The as-synthesized core-shell nanocubes exhibited a strong localized surface plasmon resonance peak at 581 nm and the resonance was dominated by absorption rather than scattering. It is expected that the Au@Cu nanocubes with uniform and controllable sizes will find use in a variety of applications such as plasmonics and catalysis.
关键词： lattice mismatch,Copper nanocubes,core-shell nanocrystals,plasmonics,seed-mediated growth
更新于2025-11-19 16:56:35
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Enhanced Single-Mode Lasers of All-Inorganic Perovskite Nanocube by Localized Surface Plasmonic Effect from Au Nanoparticles
摘要： Miniaturized laser sources recently attracted considerable interests as their potential applications in optical communication, data storage, and imaging. However, high cavity losses induced by size reduction from the gain medium would lead high lasing threshold. In this work, the enhanced optical properties of CsPbBr3 perovskite nanocubes by using localized surface plasmonic effect of Au nanoparticles (NPs) were investigated. The integration of Au NPs in the poly (3, 4-ethylenedioxy-thiophene): poly (styrenesulfonate) PEDOT: PSS layer induces obviously enhancement both in the absorption and photoluminescence (PL) of CsPbBr3 perovskite nanocubes. Importantly，the lasing threshold of CsPbBr3 perovskite nanocubes is significantly reduced by ~ 33%. This study suggests that the lead halide perovskites hybridized with plasmonic nanomaterials would be promising candidates for laser devices and other optoelectronic devices with high efficiency.
关键词： Low threshold,Perovskite nanocubes,LSPR,Au nanoparticles
更新于2025-11-14 15:32:45
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Size and dimension dependent surface-enhanced Raman scattering properties of well-defined Ag nanocubes
摘要： Understanding the role of the morphology and particle–particle interactions on the plasmonic properties is of significant importance for the development of nanomaterials with excellent optical properties. However, the preparation of precisely defined nanomaterials with sizes that span a large range and their controllable self-assembly still remain a great challenge. Here, a multistep seed-mediated method has been established for preparing uniform Ag nanocubes over a broad size range from nanoscale (50 nm) to microscale (1400 nm) and with different hierarchical nanostructures range from “zero-dimension” (“0D”) to “three-dimension” (“3D”). The influence of the size and the interactions between the Ag nanocubes on their surface-enhanced Raman scattering (SERS) properties have been systematically and quantitatively investigated. It is demonstrated through experiments and finite-difference time-domain (FDTD) calculations that the SERS activity is dependent on the matching of the nanocube size to the excitation wavelength. The optimal combinations are 80, 110 and 130 nm nanocubes with respect to 532, 638 and 785 nm excitation wavelength, respectively. Furthermore, the Raman enhancement of the Ag nanocube hierarchical nanostructures increases rapidly from “0D” to “3D”, due to the extra increase of the hot spots that is attributed to the out-of-plane plasmonic coupling realized in the “3D” hierarchical nanostructures. This work clearly illustrates the quantitative role of the size and dimension of Ag nanocubes on their SERS properties and provides fundamental information for the design of advanced nanomaterials with higher SERS sensitivity.
关键词： Silver nanocubes,Self-assembly,Surface-enhanced Raman scattering,Seed-mediated method
更新于2025-09-23 15:23:52
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Cuprous oxide nanocubes decorated reduced graphene oxide nanosheets embedded in chitosan matrix: A versatile electrode material for stable supercapacitor and sensing applications
摘要： Herein, we report cuprous oxide nanocubes decorated reduced graphene oxide (CNC-rGO) immersed in chitosan matrix as a versatile and enhanced electrochemically active electrode material for both supercapacitor and hydrogen peroxide (H2O2) sensor applications. The CNC-rGO was synthesized by one-pot scalable chemical precipitation method. The morphology and crystal structure of as-synthesized hybrid material was characterized by field emission scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The CNC-rGO hybrid material immersed in the chitosan matrix was used as an enhanced electrochemically active electrode material for supercapacitor and hydrogen peroxide (H2O2) sensor. The fabricated CNC-rGO hybrid in chitosan matrix as an electrode showed remarkable charge storage capacity of 772.3 F g-1 (12.87 mA h g-1) at a current density of 0.2 A g-1 with high cyclic stability over 2000 charge-discharge cycles. Similarly, H2O2 sensing performance of the same electrode exhibits very high sensitivity of 0.33 A M-1 cm-2 within a linear range of detection of 20-160 μM. Thus, the synthesized CNC-rGO hybrid material composed of numerous cuprous nanocubes on rGO nanosheets with large active sites showed enhanced electrochemical activity beneficial towards the supercapacitor and H2O2 sensor applications.
关键词： copper oxide nanocubes,chitosan,supercapacitor,H2O2 sensor,reduced graphene oxide
更新于2025-09-23 15:23:52
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Enhanced light harvesting and electron-hole separation for efficient photocatalytic hydrogen evolution over Cu7S4-enwrapped Cu2O nanocubes
摘要： P-type Cu2O is an advantageous photocatalyst as the appropriate bandgap structure and low-cost. However, poor photocatalytic and instability of such promising material is still a great challenge. Here the core-shell Cu7S4-coated Cu2O nanocubes (Cu2O/Cu7S4 NCs) were successfully synthesized by solution method coupled with anion exchange, integrated structure of Cu2O/Cu7S4 NCs exhibited apparent improved photocatalytic hydrogen evolution activity compared with Cu2O photocatalyst. Particularly, Cu2O/Cu7S4 NCs had a high hydrogen production rate of 1689.00 μmol·g-1·h-1 under full spectra irradiation with additives of Na2SO3, which was higher than that of Cu2O NCs with a factor of 1.71 times. Excellent synergistic effect of Cu2O and Cu7S4 can be responsible for the improved hydrogen evolution properties, namely, the presence of Cu7S4 with localized surface plasma resonance (LSPR) can promote the photogenerated electrons transfer from the Cu2O surface, prolong the photogenerated holes lifetime, accelerate the separation of photogenerated electrons and holes, and ameliorate the photoelectric properties of semiconductors. The in situ formed multifunctional Cu7S4 layer offers a promising avenue to design photocathodes rationally for photocatalytic water reduction.
关键词： Photocatalyst,Localized surface plasma resonance,Electron-hole separation,Hydrogen evolution reaction,Cu2O/Cu7S4 nanocubes
更新于2025-09-23 15:22:29
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Plasmon-Enhanced Photodegradation of Ionic Liquids with Ag Nanocubes/ZnO Microsphere Composites
摘要： Ionic liquids (ILs) have been a hot topic in the past decades because of their unique properties and promising applications in various areas. However, the toxicity of ILs and their possible risk to the environment and aquatic organisms have also been confirmed. Therefore, it is imperative to seek an efficient way to remove or degrade ILs in the polluted aqueous system. In this work, Ag nanocubes/ZnO microspheres composites have been designed, prepared, and used for the photocatalytic degradation of eight commonly used imidazolium-based ILs in aqueous solution. It is found that ZnO semiconductor photocatalyst with an Ag content of 1.12 at. % can degrade 90% of all these ILs within 7 h. The structural characterization, photoluminescence analysis, and discrete dipole approximation calculations showed that the loading of Ag nanocubes onto ZnO microspheres significantly improves the performance of ZnO for the IL degradation through hot electron transfer and electrical field enhancement. In addition, the formed intermediates in the degradation process of [C4 mim]Cl have been detected by gas chromatography?mass spectroscopy. A possible degradation mechanism is proposed and compared with those previously reported in the chemical degradation.
关键词： Photodegradation,Ionic liquids,Plasmon-enhanced,ZnO microspheres,Ag nanocubes
更新于2025-09-23 15:21:21
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Prussian Blue Nanocubesa??SnO <sub/>2</sub> Quantum Dotsa??Reduced Graphene Oxide Ternary Nanocomposite: An Efficient Nona??noblea??metal Electrocatalyst for Nona??enzymatic Detection of H <sub/>2</sub> O <sub/>2</sub>
摘要： Developing non-noble-metal electrocatalyst for non-enzymatic H2O2 sensing is highly attractive. A facile, two-step approach has been utilized for the synthesis of PBNCs/SnO2 QDs/RGO ternary nanocomposite. TEM, SEM, XPS, and XRD techniques were used to the characterize the structural and morphological properties of synthesized ternary nanocomposite. The synthesized ternary nanocomposite has been examined as an electrode material for the electrochemical detection of H2O2 using the Amperometry technique. Under optimum conditions, PBNCs/SnO2 QDs/RGO ternary nanocomposite performed very well in the electrocatalytic reduction of H2O2 with a linear dynamic range from 25-225 μM (R2 = 0.996) with a low detection limit of 71 nM (S/N=3). Compared to the recent literature, PBNCs/SnO2QDs/RGO ternary nanocomposite based modified electrode exhibit a wider linear dynamic range with a low detection limit. Furthermore, PBNCs/SnO2 QDs/RGO ternary nanocomposite based modified electrode showed an excellent anti-interference ability against various common interfering agents. The practical applicability of ternary nanocomposite based modified electrode was further extended to determine the H2O2 in tap water with acceptable recovery. The present performance of PBNCs/SnO2 QDs/RGO ternary nanocomposite material towards H2O2 sensing might widen its application for developing a new type of non-noble metal-based non-enzymatic electrochemical biosensors.
关键词： Hydrogen peroxide,Graphene,Non-enzymatic sensor,SnO2 quantum dots,Non-noble-metal electrocatalyst,Prussian blue nanocubes
更新于2025-09-23 15:21:01
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MoS2/Ni-CoSx porous nanocubes derived from Ni–Co prussian-blue analogs as enhanced Pt-free electrode catalysts for high-efficiency dye-sensitized solar cells
摘要： Owing to the modifiable compositions and morphologies, high-efficiency clean energy catalysts with complex functional structures attract wide-ranging attention. Herein, this report focuses on the controllably morphological MoS2-doped NiS2/Co3S4 nanocubes which are derived from nickel-cobalt Prussian-blue analogs. After annealing in N2 flow, MoS2/Ni-CoSx porous nanocubes are prepared via regulating the reactant ratios (1/2, 1/1 and 2/1) between (NH4)2MoS4 and Ni–Co Prussian-blue analogs. In the synthesis progress, (NH4)2MoS4 is applied as a bifunctional dopant source, which can expediently offer Mo and S elements simultaneously. The quaternary porous MoS2/Ni-CoSx (1/1) with the reasonable chemical composition, considerable specific surface area (86.7 m2 g?1) and excellent electrocatalytic property can be selected as the representative counter electrode catalyst in dye-sensitized solar cells. Furthermore, the solar cell with MoS2/Ni-CoSx (1/1) exhibits a higher power conversion efficiency (9.80%) than that of Pt (8.19%) under a standard irradiation.
关键词： Prussian-blue analogs,Dye-sensitized solar cells,(NH4)2MoS4,Nanocubes,MoS2/Ni-CoSx,Electrocatalytic property
更新于2025-09-19 17:13:59
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Plasmonic nanopapers: flexible, stable and sensitive multiplex PUF tags for unclonable anti-counterfeiting applications
摘要： Highly flexible and stable plasmonic nanopaper comprised of silver nanocubes and cellulose nanofibres was fabricated through a self-assembly-assisted vacuum filtration method. It shows significant enhancement of the fluorescence emission with an enhancement factor of 3.6 and Raman scattering with an enhancement factor of ~104, excellent mechanical properties with tensile strength of 62.9 MPa and Young’s modulus of 690.9 ± 40 MPa, and a random distribution of Raman intensity across the whole nanopaper. The plasmonic nanopapers were encoded with multiplexed optical signals including surface plasmon resonance, fluorescence and SERS for anti-counterfeiting applications, thus increasing security levels. The surface plasmon resonance and fluorescence information are used as the first layer of security and can be easily verified by the naked eye, while the unclonable SERS mapping is used as the second layer of security and can be readily authenticated by Raman spectroscopy using a computer vision technique.
关键词： cellulose nanofibres,fluorescence enhancement,silver nanocubes,anti-counterfeiting,SERS,plasmonic nanopaper
更新于2025-09-19 17:13:59
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PVP-assisted laser ablation growth of Ag nanocubes anchored on reduced graphene oxide (rGO) for efficient photocatalytic CO2 reduction
摘要： Metallic nanoparticles loaded graphene nanocomposites have been widely studied for various scienti?c and technological applications. In this study, a facile method was reported to realize a straightforward growth of shape and size-controllable of metallic nanoparticles, and the subsequent hybridization with graphene in solution by strategically coupling wet-chemical route and laser ablation. By mixing graphene oxide (GO) with a tunable concentration level of polyvinylpyrrolidone (PVP) in aqueous solution, Ag nanocubes with a face-centered cubic crystal structure were generated by pulsed laser ablation and then mounted on GO nanosheets with the assistance of PVP. The preferential adsorption of PVP to Ag (100) crystal face led to the production of Ag nanocubes with exposed (100) facet. The result showed that the morphological yield of spherical particles decreased with the increase in PVP concentration. X-ray di?raction (XRD) and UV–visible spectroscopy analyses con?rmed that GO was partially reduced. In the reduction of CO2 gas, the photocatalytic conversion rate could achieve 133.1 μmol g?1 in 6 hrs for cubic Ag-loaded reduced GO composites.
关键词： Ag nanocubes,PVP,Laser ablation,CO2 reduction,Photocatalysis,Graphene oxide
更新于2025-09-12 10:27:22