- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Phase-Control-Enabled Enhancement in Hydrophilicity and Mechanical Toughness in Nanocrystalline Tungsten Oxide Films for Energy-Related Applications
摘要： We report on the phase-control-enabled enhancement in the hydrophilicity and mechanical properties of nanostructured WO3 films for energy-related applications. Nanostructured WO3 films were fabricated by utilizing reactive magnetron sputter deposition onto silicon (100) substrates with varying deposition temperature (Ts = 25?500 °C) at a fixed oxygen partial pressure of ～4 mTorr. Extensive characterization performed indicates that the fundamental surface/interface structure?phase?hydrophilicity?mechanical property correlation enables tailoring nanocrystalline WO3 films to meet the requirements of various technological applications. Crystal structure, surface/interface morphology, and microstructure characterization indicate the deposition processing conditions induce phase transformations and surface/interface quality variation, which in turn controls the hydrophilicity and mechanical behavior of WO3 films. Carefully tuned processing conditions induce an amorphous to crystalline structural transformation, which progresses through amorphous to monoclinic to tetragonal phases, coupled with variation in surface roughness and crystallite size. Mechanical characterization using nanoindentation reveals that the mechanical response, in terms of hardness (H), elastic modulus (E), and scratch parameters, of WO3 films is highly sensitive to their phase and microstructure evolution. Nanostructured WO3 films crystallized in monoclinic phase exhibit superior mechanical response compared to either amorphous or tetragonal phase WO3 films. The maximum hardness (～38 GPa) and elastic modulus (～320 GPa) values were obtained for WO3 films deposited at Ts = 400 °C. The phase transformation sequence coupled with surface/interface structure affects the contact angle values significantly. The contact angle decreases significantly from 70° to nearly 5° with variation in phase, microstructure, and surface/interface quality of WO3 films. A direct structure?phase?microstructure?hydrophilicity?mechanical property relationship found suggest that tuning properties of WO3 films for photoelectrochemical, photocatalytic, and energy-related applications can be achieved by tuning the deposition conditions and controlling the phase at the nanoscale dimensions.
关键词： WO3 thin films,hydrophilicity,phase transformation,nanostructure
更新于2025-09-23 15:19:57
-
Enhancement of power conversion efficiency of Al/ZnO/p-Si/Al heterojunction solar cell by modifying morphology of ZnO nanostructure
摘要： This paper proposes a cost-effective sol–gel method for synthesis of ZnO nanostructure to make Al/ZnO/p-Si/Al heterojunction solar cell. Here, crystalline ZnO nanostructure was grown on p-silicon and annealed at 300 °C, 400 °C and 500 °C for application in heterojunction solar cell. The optimum temperature for obtaining uniform crystalline nanostructure was 500 °C, as confirmed from XRD and SEM imaging. As investigated by UV–Vis spectroscopy, the ZnO nanostructure layer exhibited high transmittance in the visible spectrum and has a direct band gap of 3.26–3.28 eV. The power conversion efficiency of Al/ZnO/p-Si/Al solar cell is enhanced from 1.06 to 2.22% due to increase in surface area of ZnO by formation of crystalline nanostructure due to increase of annealing temperature. The optimum value of short-circuit current (Isc) and open-circuit voltage (Voc) was measured using current–voltage (I–V) under AM 1.5 illuminations and found to be 9.97 mA and 460 mV, respectively.
关键词： Power conversion efficiency,Sol–gel method,Annealing temperature,Heterojunction solar cell,ZnO nanostructure
更新于2025-09-23 15:19:57
-
Size dependence of emission enhancement of Tris(8-hydroxyquinolinato) aluminum with plasmonic Al nanostructure
摘要： It is essential to understand which mechanism of localized surface plasmon (LSP) emission enhancement is to be utilized when combining plasmonic metal nanostructures with an emissive material to produce an optoelectronic device. Herein, we report on the size dependence and time-resolved dynamics of photoluminescence (PL) enhancement using three sizes of aluminum nanotriangles (Al NTs) on emission by tris(8-hydroxyquinolinato) aluminum (Alq3) for elucidating its enhancement mechanism. Al nanostructures were fabricated using a nanosphere lithography technique. Two-dimensionally aligned polystyrene (PSt) beads with different diameters were used as mask templates for obtaining the Al NTs. The absorption peaks red-shifted with increasing Al NT size, and hence, were attributed to the LSP resonance. From PL of Alq3 with and without Al NTs, 2–3 fold PL enhancements were observed among the samples with different Al NTs sizes. The significant shortening of the PL lifetime was observed only in Alq3/Al NTs using Ps500, indicating the effective coupling of LSP of Al NTs and the emission, which is also evidenced from the overlapping the PL peak and the LSP absorption. In contrast, the PL emission enhancement due to LSP coupling with the absorption process of Alq3 was dominant in Alq3/Al NTs using Ps200, suggested from the similarity of the PL decay curve with that of bare Alq3, and the excitation energy matching with LSP resonance. From these observation, we can distinguish the LSP coupling process (absorption or emission) from the presence or absence of lifetime enhancement in the time-resolved PL measurements, offering a guideline for designing the optical devices incorporating the metal nanostructures.
关键词： Aluminum nanostructure,Plasmon effect,Time-resolved measurement,Photoluminescence,Localized surface plasmon
更新于2025-09-23 15:19:57
-
Plasmonic biosensors fabricated by galvanic displacement reactions for monitoring biomolecular interactions in real time
摘要： Optical sensors are prepared by reduction of gold ions using freshly etched hydride-terminated porous silicon, and their ability to specifically detect binding between protein A/rabbit IgG and asialofetuin/Erythrina cristagalli lectin is studied. The fabrication process is simple, fast, and reproducible, and does not require complicated lab equipment. The resulting nanostructured gold layer on silicon shows an optical response in the visible range based on the excitation of localized surface plasmon resonance. Variations in the refractive index of the surrounding medium result in a color change of the sensor which can be observed by the naked eye. By monitoring the spectral position of the localized surface plasmon resonance using reflectance spectroscopy, a bulk sensitivity of 296 nm ± 3 nm/RIU is determined. Furthermore, selectivity to target analytes is conferred to the sensor through functionalization of its surface with appropriate capture probes. For this purpose, biomolecules are deposited either by physical adsorption or by covalent coupling. Both strategies are successfully tested, i.e., the optical response of the sensor is dependent on the concentration of respective target analyte in the solution facilitating the determination of equilibrium dissociation constants for protein A/rabbit IgG as well as asialofetuin/Erythrina cristagalli lectin which are in accordance with reported values in literature. These results demonstrate the potential of the developed optical sensor for cost-efficient biosensor applications.
关键词： Surface functionalization,Optical sensor,Lectin,Localized surface plasmon resonance,Biomolecular interactions,Gold nanostructure
更新于2025-09-23 15:19:57
-
Controlled Synthesis of Au Nanocrystals-Metal Selenide Hybrid Nanostructures toward Plasmon-Enhanced Photoelectrochemical Energy Conversion
摘要： A simple method for the controllable synthesis of Au nanocrystals–metal selenide hybrid nanostructures via amino acid guiding strategy is proposed. The results show that the symmetric overgrowth mode of PbSe shells on Au nanorods can be precisely manipulated by only adjusting the initial concentration of Pb2+. The shape of Au–PbSe hybrids can evolve from dumbbell-like to yolk-shell. Interestingly, the plasmonic absorption enhancement could be tuned by the symmetry of these hybrid nanostructures. This provides an e?ective pathway for maneuvering plasmon-induced energy transfer in metal–semiconductor hybrids. In addition, the photoactivities of Au–PbSe nanorods sensitized TiO2 electrodes have been further evaluated. Owing to the synergism between e?ective plasmonic enhancement e?ect and e?cient interfacial charge transfer in these hybrid nanostructures, the Au–PbSe yolk-shell nanorods exhibit an outstanding photocurrent activity. Their photocurrent density is 4.38 times larger than that of Au–PbSe dumbbell-like nanorods under light irradiation at λ > 600 nm. As a versatile method, the proposed strategy can also be employed to synthesize other metal–selenide hybrid nanostructures (such as Au–CdSe, Au–Bi2Se3 and Au–CuSe).
关键词： surface plasmon resonance,morphology manipulation,gold-metal selenide,photoelectrochemical response,hollow hybrid nanostructure
更新于2025-09-23 15:19:57
-
Broadband aggregation-independent plasmonic absorber for highly efficient solar steam generation
摘要： Achieving efficient solar steam generation under natural sunlight has huge potential for sewage purification and seawater desalination. Plasmonic resonance has been extensively exploited for enhancing and extending the range of optical absorption. Up till now, most reported broadband plasmonic solar absorbers are designed by compact aggregation or engineering plasmonic architectures. In this work, we develop a new plasmonic absorber using gold nanostructure with the shape of a trepang (nano-trepang). By rationally regulated anisotropy at the single nanoparticle level, the nano-trepang show good optical absorption over the entire solar spectrum (92.9 %) with no requirement of engineering nanoparticles aggregation or constructing plasmonic architecture. The nano-trepang were then loaded into a polymeric aerogel and the network shows excellent solar-to-vapor energy conversion of 79.3%. Under 1 sun AM1.5 G irradiation, a stable solar vapor rate of 2.7 kg m-2 h-1 can be achieved, with high performance of anti-salt precipitation in the practice seawater steam generation. This work shows a broadband plasmonic absorber with aggregation-independent performance for high-efficient solar stream generation and provides new strategy for practical solar desalination.
关键词： plasmonic absorber,solar desalination,gold nanostructure,solar steam generation,nano-trepang
更新于2025-09-23 15:19:57
-
Nanostructuring of honeycomb-like polystyrene with excimer laser
摘要： This paper is aimed on the construction of honeycomb like patterns (HCP) with defined dimensions of pores on activated solid-state substrate. Dip coating technique with improved phase separation was used for pattern preparation, subsequent nanostructuring was realized with an excimer laser. Polystyrene patterns were prepared on perfluorethylenepropylene, which were subsequently treated with laser wavelength 248 nm. The main goal was to prepare honeycomb like pattern and by interaction of such microstructure with an excimer laser to prepare superposed structure. This idea was fully fulfilled, uniform micropattern on perfluorinated polymer was prepared, with several laser fluences and number of pulses to be tested subsequently. Optimal conditions of KrF exposure were determined to be 6000 pulses and interval of laser treatment from 8 to 16 mJ.cm?2, by this combination of input parameters a superposed globular nanostructure was constructed on honeycomb-like polystyrene microstructure. Surface wettability, morphology and chemistry of nanopatterned microstructures were changed significantly, oxygen concentration of treated substrates was significantly increased. Particular stages of globular pattern formation were studied and described in detail by atomic force microscopy, scanning electron microscopy, EDS/EDX and XPS analysis. Elemental mapping was applied for detailed analysis of prepared superposed pattern.
关键词： Excimer laser,Perfluorethylenepropylene,Polymer,Polystyrene,Honeycomb pattern,Nanostructure
更新于2025-09-23 15:19:57
-
Morphological Evolution Induced through Heterojunction of W-decorated NiO Nanoigloos: Synergistic Effect on High-performance Gas Sensors
摘要： Morphological evolution accompanying a surface roughening and the preferred orientation is an effective way to realize a high-performance gas sensor because of its significant potential as a chemical catalyst by chemical potentials and atomic energy states. In this work, we investigated the heterojunction of both-sided W-decorated NiO nanoigloos fabricated through RF sputtering and a soft-template method. Interestingly, the morphological evolution characterized by a pyramidal rough surface and the preferred orientation of the (111) plane was observed upon decorating the bare NiO nanoigloos with W. The underlying mechanism of the morphological evolution was precisely demonstrated based on a van der Drift competitive growth model originating from the oxygen transport and chemical strain in a lattice. The gas sensing properties of W-decorated NiO show an excellent NO2 response and selectivity when compared to other gases. In addition, high response stability was evaluated under interference gas and humidity condition. The synergistic effects on the sensing performance were interpreted based on the morphological evolution of W-decorated NiO nanoigloos.
关键词： Gas sensor,Nanostructure,Morphological evolution,Heterojunction,NO2
更新于2025-09-19 17:15:36
-
Interaction-tailored organization of large-area colloidal assemblies
摘要： Colloidal lithography is an innovative fabrication technique employing spherical, nanoscale crystals as a lithographic mask for the low cost realization of nanoscale patterning. The features of the resulting nanostructures are related to the particle size, deposition conditions and interactions involved. In this work, we studied the absorption of polystyrene spheres onto a substrate and discuss the effect of particle–substrate and particle–particle interactions on their organization. Depending on the nature and the strength of the interactions acting in the colloidal film formation, two different strategies were developed in order to control the number of particles on the surface and the interparticle distance, namely changing the salt concentration and absorption time in the particle solution. These approaches enabled the realization of large area (≈cm2) patterning of nanoscale holes (nanoholes) and nanoscale disks (nanodisks) of different sizes and materials.
关键词： localized surface plasmon resonance,large-area nanostructure patterning,colloidal lithography,spherical nanoparticles,electrostatic interactions
更新于2025-09-19 17:15:36
-
Synthesis and photocatalytic properties of electrodeposited bismuth oxyiodide on rutile/anatase TiO<sub>2</sub> heterostructure
摘要： Bismuth oxyiodide (BiOI) modified rutile/anatase TiO2 heterostructure was fabricated by a three-step process. Anatase TiO2 sheet was first formed on fluorine-doped tin oxide (FTO) glass substrate. Rutile TiO2 nanorods were then grown on anatase TiO2 sheet via a hydrothermal process. BiOI was finally coated on the surface of hierarchical TiO2 film using an electrochemical deposition method. Photocatalytic tests on degradation of methylene blue (MB) in water indicated that BiOI modified hierarchical TiO2 film possessed an excellent photocatalytic activity superior to those of the monophase anatase and rutile TiO2 films, commercial P25 film and hierarchical TiO2 film. The enhanced photocatalytic performance was probably attributed to the synergetic effects of strong visible light absorption and formation of heterojunctions by the interfaces in the BiOI / rutile TiO2 / anatase TiO2 / FTO structure, which promoted efficient separation of photoinduced electron-hole pairs. In addition, the main active species during the degradation were confirmed to be hydroxyl radicals and superoxide radicals.
关键词： hierarchical rutile/anatase TiO2,nanostructure,film,electrodeposition,charge carrier separation,visible absorption,BiOI
更新于2025-09-19 17:15:36