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Dual Management of Electrons and Photons to Get High-Performance Light Emitting Devices Based on Si Nanowires and Si Quantum Dots with Al <sub/>2</sub> O <sub/>3</sub> -Ag Hybrid Nanostructures
摘要： Silicon quantum dot (Si QD)-based light emitting devices are fabricated on Si nanowire (Si NW) arrays. Through inserting Al2O3-Ag hybrid nanostructures (Al2O3-Ag HNs) between Si NWs and Si QDs, both photoluminescence (PL) and electroluminescence (EL) are remarkably enhanced compared to the control sample. The PL enhancement can be mainly attributed to passivation effect of Al2O3 to p-type Si NWs and enlarged absorption cross-section due to the local surface plasmon resonance effect of Ag nanoparticles. The EL intensity is enhanced by 14.9-fold at the same injection current under a lower applied voltage, which may result from the high injection efficiency of electrons and the promoted waveguide effect of nanowire structures with Al2O3-Ag HNs. It is demonstrated that light emitting device performances can be well improved by careful management of both electrons and photons via controlling the interface conditions of Si NWs/Si QDs.
关键词： hybrid nanostructures,silicon nanowires,light emitting devices,silicon quantum dots
更新于2025-11-21 11:01:37
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Enhanced generation of reactive oxygen species and photocatalytic activity by Pt-based metallic nanostructures: the composition matters
摘要： The modification of semiconductor nanostructures with metallic nanocomponents can promote the separation of electron/hole from photoexited semiconductors by forming heterojunctions, thus exhibit enhanced photocatalytic activities and potential applications. In this study, Pt-based NPs, including Pt, PtCu, and PtCuCo are employed as model co-catalysts to comparatively study their capability to enhance the photocatalytic activity of TiO2 nanosheets. It was found that each of Pt, PtCu, and PtCuCo can greatly enhance the photocatalytic activity of TiO2 toward degradation of organic dyes. Using electron spin resonance spectroscopy, we demonstrated that deposition of Pt-based NPs resulted in more production of reactive oxygen species including hydroxyl radicals, superoxide, and singlet oxygen. The enhancing effects of Pt-based NPs on generation of ROS and photocatalytic activity showed same trend: PtCuCo > PtCu > Pt. The mechanism underlying the enhancement differences in Pt-based NPs may be mainly related to electronic structure change of Pt in alloying with Cu and Co. These results are valuable for designing hybrid nanomaterials with high photocatalytic efficiency for applications in water purification and antibacterial products.
关键词： photocatalysis,hybrid nanostructures,reactive oxygen species,PtCuCo,TiO2
更新于2025-09-23 15:22:29
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Unique 1D Cd <sub/>1?</sub><i> <sub/>x</sub></i> Zn <i> <sub/>x</sub></i> S@O-MoS <sub/>2</sub> /NiO <i> <sub/>x</sub></i> Nanohybrids: Highly Efficient Visible-Light-Driven Photocatalytic Hydrogen Evolution via Integrated Structural Regulation
摘要： Development of noble-metal-free photocatalysts for highly efficient sunlight-driven water splitting is of great interest. Nevertheless, for the photocatalytic H2 evolution reaction (HER), the integrated regulation study on morphology, electronic band structures, and surface active sites of catalyst is still minimal up to now. Herein, well-defined 1D Cd1?xZnxS@O-MoS2/NiOx hybrid nanostructures with enhanced activity and stability for photocatalytic HER are prepared. Interestingly, the band alignments, exposure of active sites, and interfacial charge separation of Cd1?xZnxS@O-MoS2/NiOx are optimized by tuning the Zn-doping content as well as the growth of defect-rich O-MoS2 layer and NiOx nanoparticles, which endow the hybrids with excellent HER performances. Specifically, the visible-light-driven (>420 nm) HER activity of Cd1?xZnxS@O-MoS2/NiOx with 15% Zn-doping and 0.2 wt% O-MoS2 (CZ0.15S-0.2M-NiOx) in lactic acid solution (66.08 mmol h?1 g?1) is about 25 times that of Pt loaded CZ0.15S, which is further increased to 223.17 mmol h?1 g?1 when using Na2S/Na2SO3 as the sacrificial agent. Meanwhile, in Na2S/Na2SO3 solution, the CZ0.15S-0.2M-NiOx sample demonstrates an apparent quantum yield of 64.1% at 420 nm and a good stability for HER under long-time illumination. The results presented in this work can be valuable inspirations for the exploitation of advanced materials for energy-related applications.
关键词： charge separation,1D hybrid nanostructures,photocatalytic hydrogen evolution,band alignments,active sites
更新于2025-09-23 15:22:29
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Formation of the AuNPs GO@MoS2/AuNPs Nanostructures for the SERS Application
摘要： GO nanomeshes and GO@MoS2/AuNPs nanostructures are formed on the flexible 3D Ni foam substrate for the SERS application. Smaller and denser AuNPs “hot spots” are spin-coated on such mesh-like GO@MoS2/AuNPs nanostructures to form AuNPs/GO@MoS2/AuNPs SERS substrates. The branches of GO nanomeshes are used as the homogeneous nanogaps to form the separated denser “hot spots” and absorb the molecules, resulting high electromagnetic (confirmed by the FDTD simulation) and signals enhancement. As low as 10-14 M of the Crystal Violet (CV) and Rhodamine 6G (R6G) are detected. Such flexible foam-like substrate can be used for the in-situ detection on the fish surface by scraping. DNA without label can also be easily detected by spin-coating the mixed AuNPs-DNA solution in our experiment.
关键词： AuNPs GO@MoS2/AuNPs；hybrid nanostructures；homogeneous nanogaps；SERS
更新于2025-09-23 15:21:21
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The optical response of self-organized Ag-CdTe metal-semiconductor hybrid nanostructures: Change in interaction vs number density variation
摘要： Using experimental results and a theoretical model, we establish a relation for the optical response of a mixed nanocolloid. We show that colloids prepared by mixing metal and semiconductor nanocolloids in various ratios result in a mixture composed of a particular metal-semiconductor hybrid nanostructure and unattached original particles. Thus, the properties of hybrid samples prepared by such self-organized growth are decided by the variation in number density of the hybrid and the unattached particles and not due to a continuous change in the interaction between metal nanoparticles and semiconductor quantum dots as was assumed earlier. Using these results, a method to prepare a single type of hybrid nanostructure by measuring only its optical response is presented.
关键词： nanoparticles,metal-semiconductor hybrid nanostructures,optical response,quantum dots,self-organized growth
更新于2025-09-23 15:21:21
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Enhancing interfacial charge transfer on novel 3D/1D multidimensional MoS2/TiO2 heterojunction toward efficient photoelectrocatalytic removal of levofloxacin
摘要： Structure-controlled visible light driven photo-anode with high catalytic performance, plays important roles in environmental pollutants treatment. In this work, a mild hydrothermal assisted anodization approach has been reported to design an integrated self-assembled 3D flower-like MoS2/1D TiO2 nanotube arrays (NTAs) hierarchical electrode. The constructed multidimensional electrode not only broadened the absorption spectrum response range but also promoted rapidly electron-hole pairs separation, exhibiting the excellent photoelectron catalytic (PEC) performance and stability in the degradation of target pollutants, which the photocurrent conversion efficiency was 6.5 times higher than that of pure TiO2. Furtherly, a comprehensive mechanism was proposed to explain the charge transfer on the interface of intimate integration of 3D/1D hybrid nanostructure towards PEC properties in terms of the energy band structures and DFT. Furthermore, the photo-generated active species (?OH and ?O2-) have been proved by electron paramagnetic resonance spectroscopy and fluorescence probe over the composites. Thus, this work could provide an effective strategy to design multidimensional coupled heterojunction materials toward solar energy conversion for environmental purification.
关键词： Interfacial charge transfer,Photoelectrocatalytic,Active radicals,DFT,3D/1D hybrid nanostructures
更新于2025-09-23 15:21:01
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SERS-based molecularly imprinted plasmonic sensor for highly sensitive PAH detection
摘要： A novel hybrid plasmonic platform based on the synergetic combination of a molecularly imprinted polymer (MIP) thin film with Au nanoparticles (NPs) assemblies, noted as Au@MIP, was developed for surface-enhanced Raman scattering (SERS) spectroscopy recognition of polycyclic aromatic hydrocarbons (PAHs). While the MIP trapped the PAH close to the Au surface, the plasmonic NPs enhanced the molecule Raman signal. The Au@MIP fabrication comprises a two-step procedure, first, the layer-by-layer deposition of Au NPs on glass and their further coating with a uniform MIP thin film. Profilometry analysis demonstrated that the thickness and homogeneity of the MIP film could be finely tailored by tuning different parameters such as prepolymerization time or spin-coating rate. Two different PAH molecules, pyrene or fluoranthene, were used as templates for the fabrication of pyrene- or fluoranthene-based Au@MIP substrates. The use of pyrene or fluoranthene, as a template molecule to fabricate the Au@MIP thin films, enabled its ultradetection in the nM regime with a 100-fold improvement compared with the non-imprinted plasmonic sensors (Au@NIPs). The SERS data analysis allows to estimate the binding constant of the template molecule to the MIP. The selectivity of both pyrene- and fluoranthene-based Au@MIPs was analyzed against three PAHs of different sizes. The results displayed the important role of the template molecule used for the Au@MIPs fabrication in the selectivity of the system. Finally, the practical applicability of pyrene-based Au@MIPs is shown by performing the detection of pyrene in two real samples: creek water and seawater. The design and optimization of this type of plasmonic platform pave the way for the detection of other relevant (bio)molecules in a broad range of fields such as environmental control, food safety or biomedicine.
关键词： Molecularly imprinted polymers,plasmonic sensors,polycyclic aromatic hydrocarbons,SERS,hybrid nanostructures,environmental analysis
更新于2025-09-19 17:13:59
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Synergic effect of plasmonic gold nanoparticles and graphene oxide on the performance of glucose sensing
摘要： In this study hybrid nanostructures of Au–graphene oxide (Au–GO) were synthesized via a two-step process and used to modify the glassy carbon electrode (GCE) for electrochemical measurements of glucose. The modified electrode exhibits a fast response less than 4 s, a low detection limit of 0.025 mM and a high signal-to-noise ratio (S/N) of 3.5. The fabricated sensor shows a linear response in a large concentration range from 0.0025 mM to 15 mM with a reproducible sensitivity of 84.53 mA cm?2 mM?1, which is much higher than that of the individual Au, GO and previously reported GO/rGO based sensors. In addition, the biosensor shows excellent results for human serum which agree well with those obtained using a laboratory glucometer. Moreover, the glucose amount in selective commercially available food samples and fresh juices was also successfully measured. The biosensor exhibits excellent selectivity, thermal stability and reproducibility. The enhanced and efficient sensitivity of the developed Au–GO based biosensor may be due to the synergic effects of the plasmonic Au-nanoparticles and GO. The performance of the biosensor suggests that the reported Au–GO hybrid nanostructures can provide a novel platform for developing non-enzymatic biosensors for biomedical and industrial applications.
关键词： hybrid nanostructures,Au–graphene oxide,non-enzymatic biosensor,electrochemical measurements,glucose sensing
更新于2025-09-16 10:30:52
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Tunable Optical Properties in Self‐Assembled Oxide‐Metal Hybrid Thin Films via Au‐Phase Geometry Control: From Nanopillars to Nanodisks
摘要： Plasmonic oxide-metal hybrid nanostructures exhibit unprecedented optical properties because of the nanoscale interactions between the oxide and metal components. Precise control of the geometry and arrangement of optical building blocks is key to tailoring system properties toward various nanophotonic applications. Herein, self-assembled BaTiO3-Au vertically aligned nanocomposite thin films with a series of thicknesses are fabricated using a one-step pulsed laser deposition technique. By reducing the film thickness, the geometry of Au phase is effectively tailored from nanopillars to nanodisks, with the aspect ratio (height/width) varied from ≈4.0 to ≈1.0. The experimental optical spectra and numerical simulation results demonstrate that localized surface plasmon resonance and hyperbolic dispersion wavelength can be effectively tuned in the visible to near-infrared regime by varying the film thickness due to the change of Au aspect ratio and free electron density. This study demonstrates a feasible approach in tuning the optical responses in hybrid oxide-metal nanostructures, and opens up enormous possibilities in design and fabrication of novel optical components toward all optical integrated devices.
关键词： tunability,hybrid nanostructures,plasmonic Au nanostructures,localized surface plasmon resonance,hyperbolic dispersion
更新于2025-09-12 10:27:22