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Blue-emitting and self-assembled thinner perovskite CsPbBr <sub/>3</sub> nanoplates: Synthesis and formation mechanism
摘要： Low dimensional semiconductor nanomaterials have a great promise for a variety of applications due to their size-dependent and excellent optoelectronic properties. In this work, we developed a strategy to synthesize uniform and very thin CsPbBr3 perovskite nanoplates (NPls) by introducing additional metal bromides. The CsPbBr3 NPls, self-assembled to a face-to-face stacked state, had a thickness of 4.4 nm (equal to only 2 monolayers, 2 MLs) and showed a maximum emission at 437 nm and a narrow FWHM of 14 nm. The formation mechanism of the CsPbBr3 NPls by adding FeBr3 was ascribed to the constrained growth of CsPbBr3 nanocubes when the surface of Cs+ ions was substituted by the protonated oleylammonium from the byproduct OLA-HBr.
关键词： blue-emitting,quantum confinement,self-assembly,CsPbBr3,perovskite nanoplates
更新于2025-09-23 15:19:57
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Morphology Transformation of Chalcogenide Nanoparticles Triggered by Cation Exchange Reactions
摘要： Plenty of chalcogenide families with tremendous potential for functional applications remain unexplored due to the limitations of conventional synthesis methods. However, cation exchange reactions in colloidal synthesis offer an alternative way to overcome these limitations and provide a route to synthesize pure phases and morphologies that otherwise are challenging to achieve. In this work, we demonstrate the possibility of Sb3+ to undergo cation exchange reactions with Cu+ in Cu2-xSe nanoparticles and study an uncommon morphology transformation from Cu2-xSe nanoparticles to Cu3SbSe3 nanoplates. The morphology transformation is dictated by a growth process of assembly and merging of primary nanoparticles triggered by the incorporation of Sb cations into the Cu2-xSe lattice and the rearrangement of the anion framework. By studying this unprecedented phenomenon in cation exchange reactions and adding Sb to the list of available elements for exchange, this work provides an insight of the unexplored potential of cation exchange reactions and opens the possibility to synthesize complex Cu-based chalcogenide materials.
关键词： nanoparticles,chalcogenide,morphology transformation,cation exchange,Cu3SbSe3 nanoplates
更新于2025-09-23 15:19:57
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Nonlocal analytical solution of functionally graded multilayered one-dimensional hexagonal piezoelectric quasicrystal nanoplates
摘要： Based on the nonlocal elasticity theory, the static bending deformation of a functionally graded multilayered one-dimensional (1D) hexagonal piezoelectric quasicrystal (PQC) simply supported nanoplate is investigated under surface mechanical loadings. The functionally graded material is assumed to be exponential along the thickness direction. By utilizing the pseudo-Stroh formalism and propagator matrix method, exact closed-form solutions of functionally graded multilayered 1D hexagonal PQC nanoplates are then obtained by assuming that the layer interfaces are perfectly contacted. Numerical examples for six kinds of sandwich functionally graded nanoplates made up of piezoelectric crystals, quasicrystal and PQC are presented to illustrate the influence of the exponential factor, nonlocal parameter and stacking sequence on the phonon, phason and electric fields, which play an important role in designing new composite structures in engineering.
关键词： propagator matrix method,nanoplates,functionally graded materials,piezoelectric quasicrystals,pseudo-Stroh formalism,nonlocal elasticity theory,exact solutions
更新于2025-09-19 17:15:36
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Enhanced UV-Vis-NIR activated photocatalytic activity from Fe <sup>3+</sup> -doped BiOBr:Yb <sup>3+</sup> /Er <sup>3+</sup> upconversion nanoplates: synergistic effect and mechanism insight
摘要： Upconversion (UC) materials are recognized as promising candidates to harvest solar energy for photocatalysis. In this work, a simple strategy for simultaneously enhancing the UC luminescence and photocatalytic efficiency of BiOBr:Yb3+/Er3+ nanoplates through Fe3+ ion doping is reported. Compared to the Fe3+-free sample, the UC emission intensity was significantly enhanced through tailoring of the crystal symmetry by Fe3+ ions. Experiment and DFT calculations reveal that the introduction of Fe3+ ions resulted in the formation of an impurity energy level, extending to the light absorption region. As expected, the Fe3+-doped BiOBr:Yb3+/Er3+ nanoplates exhibit a wide photoresponse from the UV to NIR regions, good stability, and obviously enhanced photocatalytic activities compared with the BiOBr:Yb3+/Er3+ nanoplates in the degradation of RhB. The boosted photocatalytic activity can be attributed to the synergic effect of the efficient utilization of UC luminescence and Fe3+ doping, where Fe3+ doping could improve the light harvesting capacity, enhance the separation efficiency of electron and hole (e?/h+) pairs, and promote the production of highly oxidative species. This work not only provides a promising system for the efficient utilization of solar light, but also offers a feasible guideline for the further design of broad-spectrum active photocatalysts.
关键词： Enhanced UV-Vis-NIR activated photocatalytic activity,mechanism insight,Fe3+-doped BiOBr:Yb3+/Er3+ upconversion nanoplates,synergistic effect
更新于2025-09-19 17:15:36
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Resonant energy transfer and light scattering enhancement of plasmonic random lasers embedded with silver nanoplates
摘要： The resonant energy transfer enhancement from a plasmonic random laser (PRL) has been investigated by means of a dye-covered PVA film with embedded silver nanoplates (DC-PVA/AgNPs). Different sizes and morphologies of AgNPs were adopted to shift the localized surface plasmon resonance (LSPR) and intensify recurrent light scattering between the AgNPs. For better overlap between surface plasmon resonance and the photoluminescence of fluorescent molecules with appropriately-sized silver nanoprisms, the slope efficiency of the PRL was greatly enhanced and the lasing threshold was obviously reduced. In addition, the photon lifetime for the DC-PVA/AgNPs film reveals an apparent decline around 1.39 ns owing to better coupling with LSPR. The stronger light scattering of samples with bigger-sized silver nanoprisms has been demonstrated by coherent back scattering measurements, which reveals a smaller transport mean free path around 3.3 mm. With a-stable analysis, it has been successfully demonstrated that the tail exponent a can be regarded as an identifier of the threshold of random lasing.
关键词： localized surface plasmon resonance,resonant energy transfer,silver nanoplates,light scattering enhancement,plasmonic random laser
更新于2025-09-19 17:13:59
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Non-layered ZnSb nanoplates for room temperature infrared polarized photodetectors
摘要： Non-layered 2D ZnSb nanoplates are successfully synthesized by chemical vapor deposition, which possess narrow band gap and novel anisotropic properties. Infrared polarized photodetectors based on the ZnSb nanoplates are designed and exhibit high responsivity, fast photoresponse speed, great stability, high anisotropic conductivity and linear polarization sensitivity.
关键词： anisotropic properties,ZnSb nanoplates,narrow band gap,chemical vapor deposition,infrared polarized photodetectors
更新于2025-09-19 17:13:59
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Controlled Synthesis of Triangular Silver Nanoplates by Gelatin–Chitosan Mixture and the Influence of Their Shape on Antibacterial Activity
摘要： Triangular silver nanoplates were prepared by using the seeding growth approach with the presence of citrate-stabilized silver seeds and a mixture of gelatin–chitosan as the protecting agent. By understanding the critical role of reaction components, the synthesis process was improved to prepare the triangular nanoplates with high yield and e?ciency. Di?erent morphologies of silver nanostructures, such as triangular nanoplates, hexagonal nanoprisms, or nanodisks, can be obtained by changing experimental parameters, including precursor AgNO3 volume, gelatin–chitosan concentration ratios, and the pH conditions. The edge lengths of triangular silver nanoplates were successfully controlled, primarily through the addition of silver nitrate under appropriate condition. As-prepared triangular silver nanoplates were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), UV-Vis, Fourier transform infrared spectroscopy (FT-IR), and X-Ray di?raction (XRD). Silver nanoplates had an average edge length of 65–80 nm depending on experimental conditions and exhibited a surface plasma resonance absorbance peak at 340, 450, and 700 nm. The speci?c interactions of gelatin and chitosan with triangular AgNPs were demonstrated by FT-IR. Based on the characterization, the growth mechanism of triangular silver nanoplates was theoretically proposed regarding the twinned crystal of the initial nanoparticle seeds and the crystal face-blocking role of the gelatin–chitosan mixture. Moreover, the antibacterial activity of triangular silver nanoplates was considerably improved in comparison with that of spherical shape when tested against Gram-positive and Gram-negative bacteria species, with 6.0 ug/mL of triangular silver nanoplates as the MBC (Minimum bactericidal concentration) for Escherichia coli and Vibrio cholera, and 8.0 ug/mL as the MBC for Staphylococcus aureus and Pseudomonas aeruginosa. The MIC (Minimum inhibitory concentration) of triangular Ag nanoplates was 4.0 ug/mL for E. coli, V. cholera, S. aureus, and P. aeruginosa.
关键词： seeding growth approach,triangular silver nanoplates,gelatin,antibacterial activity
更新于2025-09-16 10:30:52
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Hierarchical NiO@NiS@graphene nanocomposite as a sustainable counter electrode for Pt free dye-sensitized solar cell
摘要： Recent studies in DSSC has been concentrated on developing counter electrode with low cost materials which has high power conversion efficiency, as well as high catalytic property. NiO has been studied as CE for high short circuit current in DSSC because of its wide bandgap. In this work nickel oxide@nickel sulfide@graphene (NiO@NiS@G) nanocomposite was synthesized by hydrothermal method. Structural composition of NiO@NiS@G nanocomposite was revealed by X-ray diffraction (XRD) and confirm the formation of NiO@NiS@G nanocomposites. Raman spectroscopy was the most effective tool for the analysis of carbon-based materials. The D band and G band of Raman spectrum confirmed the conversion of graphene (G) from graphene oxide (GO). X-ray photoelectron spectroscopy (XPS) shows the presence of Ni, O, C and S atoms in the composition. The morphology analysis revealed the formation of NiO@NiS nanoplates anchored on the surface of the graphene sheets. The as-synthesized materials were coated on FTO (fluorine-doped tin oxide) substrate by spray coat technique and their catalytic properties were studied. The electrochemical activity (peak separation Epp) of NiO@NiS@G nanocomposite (391 mV) was high compared to NiO@NiS (496 mV) and exhibited excellent stability compared with NiO@NiS. Further, the charge transfer resistance of commercial Pt, NiO@NiS@G, and Nio@NiS has been measured by Electrochemical Impedance Spectroscopy (EIS), where corresponds resistance values of CEs are 15.7, 23.2, and 36.8 Ω, respectively. The efficiency of a solar cell with NiO@NiS@G is 2.10 % where it high compared with NiO@NiS (1.68%).
关键词： NiO@NiS@G,Counter electrode,Electrochemical activity,graphene,nanoplates
更新于2025-09-16 10:30:52
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Stable all-fiber passively Q-switched erbium-doped fiber laser based on plasmonic Zn doped CuGaO <sub/>2</sub> nanoplates
摘要： In this letter, we synthesized p-type Zn doped hexagonal CuGaO2 (CGZO) nanoplates (NPs) by hydrothermal reaction and utilized the nonlinear optical properties of these plasmonic NPs to realized stable passively Q-switched erbium-doped fiber laser output. We achieved tunable saturable absorbers (SAs) by changing the doping ratio of CGZO NPs. With the increase of the doping ratio, pulse duration decreases from 2.532 μs to 2.276 μs and the optical-optical conversion efficiency of the Q-switched laser increases from 1.36% to 1.70%. Our result suggests that CGZO is promising to allow tunable SAs to generate passively Q-switched fiber lasers.
关键词： Q-switched fiber laser,plasmonic Zn doped CuGaO2 nanoplates,saturable absorbers,nonlinear optical properties
更新于2025-09-11 14:15:04
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Influence of the Silver Nanocrystal Shape on the Luminous Efficiency of Blue-Emitting Polymer Light-Emitting Diodes
摘要： Truncated silver nanodecahedrons (TAgNDs) and truncated silver nanoplates (TAgNPs) fabricated via chemical reduction and photochemical methods were added to poly[3,4-ethylenedioxythiophene]:poly[styrenesulfonate] (PEDOT:PSS) as a dopant to promote the luminous efficiency of blue-emitting polymer light-emitting diodes (PLEDs). The differences in shape between TAgNDs and TAgNPs result in better dispersion of TAgNDs in PEDOT:PSS. Therefore, at an optimal doping concentration (the distributed density in the light-emitting region is 6.88 μg cm?2 for TAgNDs and 5.16 μg cm?2 for TAgNPs), the average current efficacy and maximum electroluminescence intensity enhancement factor for TAgNDs-doped PLED were 4.18 cd A?1 and 420% respectively, which are much higher than those for TAgNPs-doped PLED (1.83 cd A?1 and 200%) at a luminescence wavelength of 440 nm.
关键词： truncated silver nanoplates,blue-emitting polymer light-emitting diodes,luminous efficiency,truncated silver nanodecahedrons
更新于2025-09-11 14:15:04