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Photodegradation of thiophene over ZrO2–SiO2 nanoparticles: impact of copper decoration on their photocatalytic activity
摘要： A sol–gel technique was useful for the synthesis of zirconia–silica nanoparticles. Metallic copper has decorated zirconia–silica nanoparticles via photo-assisted deposition method, decorated copper mass percent was varied from 0.5, 1.0, 1.5, and 2.0 wt%. XRD results confirm that decoration of zirconia–silica nanoparticles by copper did not alert XRD pattern of zirconia–silica nanoparticles and there are no peaks for copper or copper oxide, due to high dispersion of copper above a surface of zirconia–silica nanoparticles. The decoration of zirconia–silica nanoparticles by copper was reduced band gap energy of zirconia–silica nanoparticles from 3.20 to 2.35 eV with 1.5 wt% Cu decoration. Photocatalytic oxidation of thiophene in presence of visible light was selected to measure the impact of metallic copper on photocatalytic activity of zirconia–silica nanoparticles. 1.5 wt% Cu-decorated zirconia–silica nanoparticles can degrade 100% of thiophene within 90 min.
关键词： ZrO2–SiO2,Sol–gel,Thiophene degradation,Cu decoration,Enhanced photocatalysis,Visible light
更新于2025-11-14 15:26:12
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Au@Cu Nanoarrays with Uniform Long-Range Ordered Structure: Synthesis and SERS Applications
摘要： The nanostructures with uniform long-range ordered structure are of crucial importance for performance standardization of high-quality surface-enhanced Raman scattering (SERS) spectra. In this paper, we described the fabrication and SERS properties of Au decorated Cu (Au@Cu) nanoarrays. The Cu nanoarrays with uniform long-range ordered structure were first synthesized by in-situ electrochemistry assembly on insulated substrate. The Cu nanoarrays can reach a size of centimeters with strictly periodic nano-microstructure, which is beneficial for the production and performance standardization of SERS substrates. Then Au nanoparticals were decorated on the Cu nanoarrays by galvanic reaction without any capping agent. The obtained Au@Cu nanoarrays exhibit excellent SERS activity for 4-Mercaptopyridine, and the sensitivity limit is as low as 10?8 M. Therefore, this facile route provides a useful platform for the fabrication of SERS substrates based on nano ordered arrays.
关键词： Au nanoparticles,Cu nanoarrays,surface decoration,surface-enhanced Raman scattering (SERS)
更新于2025-09-23 15:23:52
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Bandgap Tuning of C3N monolayer: A First-Principles Study
摘要： The newly found graphene-like material C3N exhibits great potential in a variety of important applications, due to its unique topological and electronic structures. To extend the utilization, a crucial challenge is to make its intrinsic bandgap (1.03 eV) tunable. Here we performed first-principles calculations to investigate the band structure variations of C3N monolayer under various surface modification treatments, including defect engineering, surface decoration and substitutional doping. Results show that those treatments can induce impurity states, orbital rehybridization, and n- or p-type doping simultaneously, and therefore enable effective band structure adjustment. Importantly, some linear relationships between the bandgap and doping concentration are revealed, paving the way for precise control of C3N bandgap.
关键词： Bandgap tuning,substitutional doping,defect engineering,surface decoration,g-C3N
更新于2025-09-23 15:23:52
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One-Step Solvothermal Formation of Pt Nanoparticles Decorated Pt <sup>2+</sup> -Doped α-Fe <sub/>2</sub> O <sub/>3</sub> Nanoplates with Enhanced Photocatalytic O <sub/>2</sub> Evolution
摘要： The photooxidation of water into O2 has been identified as the barrier of water-splitting, and light-driven water oxidation catalysts have been intensively explored to develop highly active water splitting materials. Despite the fascinating advantages for photocatalytic water oxidation, such as abundance in nature, inexpensiveness, low toxicity, thermo/photo-stability, and suitable electronic band structures, hematite α-Fe2O3 is a poor photocatalyst for water oxidation due to its short exciton lifetime and hole diffusion length, weak carrier mobility and shallow sunlight penetration depth. In this work, we have synthesized Pt nanoparticles decorated Pt2+-doped α-Fe2O3 nanoplates (Pt/Pt-Fe2O3 NPs) by a one-step solvothermal route, which exhibit the enhanced photoactivity and photostablity for water oxidation. The introduction of the Pt into the α-Fe2O3 by the means of elemental doping and nanoparticle decoration accounts for the enhanced performance. The doping of Pt2+ into α-Fe2O3 improves the isolation efficiency of the photo-induced carriers which remarkably increases the lifespan of hole carriers, and the adherence of metal Pt nanoparticles to the surface of α-Fe2O3 leads to formation of schottky barriers at the interface which effectively impedes the combination of photo-generated electrons and holes.
关键词： photocatalytic O2 evolution,Pt nanoparticles decoration,Pt2+ doping,schottky barrier,α-Fe2O3 nanoplates
更新于2025-09-23 15:23:52
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Metal-enhanced hydrogenation of graphene with atomic pattern
摘要： Graphene hydrogenation is an attractive approach to functionalize graphene. However, the hydrogenating treatment could only be achieved under harsh conditions due to the weak hydrogen affinity of graphene. It has also made the direct writing of electronic circuits on graphene by hydrogenation very difficult. Here we propose a metal-enhanced approach to hydrogenate graphene with atomic pattern that enables to produce hydrogenation pattern on demand. First-principles calculations reveal that certain metals (Cu, Ag, Al) attached to graphene can significantly lower the energy barrier for hydrogen binding process, while the hydrogen binding energy itself is much enhanced. Such metal-promoted hydrogenation is spatially localized, which paves the way to precisely write pre-designed hydrogenation patterns on graphene with well-controlled metallic clusters and tips.
关键词： bandgap,hydrogenation,Graphene,H-decoration pattern,metal-assisted lithography
更新于2025-09-23 15:21:21
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Optimization of the Pt Nanoparticle Size and Calcination Temperature for Enhanced Sensing Performance of Pt-Decorated In2O3 Nanorods
摘要： The surface-to-volume ratio of one-dimensional (1D) semiconductor metal-oxide sensors is an important factor for achieving good gas sensing properties because it offers a wide response area. To exploit this effect, in this study, we determined the optimal calcination temperature to maximize the specific surface area and thereby the sensitivity of the sensor. The In2O3 nanorods were synthesized by using vapor-liquid-solid growth of In2O3 powders and were decorated with the Pt nanoparticles by using a sol-gel method. Subsequently, the Pt nanoparticle-decorated In2O3 nanorods were calcined at different temperatures to determine the optimal calcination temperature. The NO2 gas sensing properties of five different samples (pristine uncalcined In2O3 nanorods, Pt-decorated uncalcined In2O3 nanorods, and Pt-decorated In2O3 nanorods calcined at 400, 600, and 800 ?C) were determined and compared. The Pt-decorated In2O3 nanorods calcined at 600 ?C showed the highest surface-to-volume ratio and the strongest response to NO2 gas. Moreover, these nanorods showed the shortest response/recovery times toward NO2. These enhanced sensing properties are attributed to a combination of increased surface-to-volume ratio (achieved through the optimal calcination) and increased electrical/chemical sensitization (provided by the noble-metal decoration).
关键词： Calcination,Pt decoration,Gas sensor,In2O3,NO2
更新于2025-09-23 15:21:21
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[BestMasters] Topographic Organization of the Pectine Neuropils in Scorpions (An Analysis of Chemosensory Afferents and the Projection Pattern in the Central Nervous System) || Effect of Humidity on the Hydrogen Sensing in Graphene Based Devices
摘要： In this work, we investigate the effect of humidity variations on the sensing performance of Pd-graphene (GR) based devices. Palladium nanoparticles are directly synthetized onto GR sheets by microwave irradiation; the optimal palladium coverage results into a sensitive and fast hydrogen device. The dynamic conductance changes exposed to different hydrogen concentrations from 2.5 to 0.2% are displayed at room temperature, using humidi?ed air as carrier gas at different Relative Humidity (RH) levels. The results show how the sensing curves in low humidity conditions have higher sensitivity with respect to humid environment. On the other hand, dry conditions negatively affect the sensing layer stability over time while humid conditions preserve the material.
关键词： Metal decoration,Hydrogen detection,Graphene
更新于2025-09-19 17:15:36
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Design of Nanoscaled Surface Morphology of TiO2–Ag2O Composite Nanorods through Sputtering Decoration Process and Their Low-Concentration NO2 Gas-Sensing Behaviors
摘要： TiO2–Ag2O composite nanorods with various Ag2O configurations were synthesized by a two-step process, in which the core TiO2 nanorods were prepared by the hydrothermal method and subsequently the Ag2O crystals were deposited by sputtering deposition. Two types of the TiO2–Ag2O composite nanorods were fabricated; specifically, discrete Ag2O particle-decorated TiO2 composite nanorods and layered Ag2O-encapsulated TiO2 core–shell nanorods were designed by controlling the sputtering duration of the Ag2O. The structural analysis revealed that the TiO2–Ag2O composite nanorods have high crystallinity. Moreover, precise control of the Ag2O sputtering duration realized the dispersive decoration of the Ag2O particles on the surfaces of the TiO2 nanorods. By contrast, aggregation of the massive Ag2O particles occurred with a prolonged Ag2O sputtering duration; this engendered a layered coverage of the Ag2O clusters on the surfaces of the TiO2 nanorods. The TiO2–Ag2O composite nanorods with different Ag2O coverage morphologies were used as chemoresistive sensors for the detection of trace amounts of NO2 gas. The NO2 gas-sensing performances of various TiO2–Ag2O composite nanorods were compared with that of pristine TiO2 nanorods. The underlying mechanisms for the enhanced sensing performance were also discussed.
关键词： composite nanorods,sputtering,nanostructured surface,surface decoration
更新于2025-09-12 10:27:22
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Intrinsic Cu nanoparticle decoration of TiO2 nanotubes: A platform for efficient noble metal free photocatalytic H2 production
摘要： In this work, we grow intrinsically Cu-doped TiO2 nanotubes (TiNTs) by self-organizing anodization of Ti–Cu binary alloys. We demonstrate that up to a copper concentration of 1.5 at.% in the alloy, self-ordered Cu2+-doped nanotubes can be grown. Under UV illumination the Cu2+ ion-doped oxide structures can be converted to nanotubes that carry metallic nanoparticles (NPs) uniformly decorated on top of the TiNTs. We investigate the formation of these metallic nanoparticles under UV illumination by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR). The resulting intrinsic copper-doped and decorated TiNTs have a strongly enhanced photocatalytic activity for H2 evolution in comparison to pristine TiNTs. Key is the light-induced conversion of the intrinsic Cu dopant to metallic copper nanoparticles that act as a stable co-catalyst for H2 generation.
关键词： intrinsic copper decoration.,photocatalytic activity,Cu doped TiO2,TiO2
更新于2025-09-10 09:29:36
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Control of Resistive Switching Voltage by Nanoparticle-Decorated Wrinkle Interface
摘要： Control of resistive switching voltage in nonvolatile memory devices plays a critical role in building commercial ultra-low power data storage technology. Here, an effective strategy to control the resistive switching voltage in polymer memory devices by interfacial engineering is presented. By creating a wrinkled surface in reduced graphene oxide (rGO) film as the conductive electrode, an electrical bistable phenomenon is observed in polymer diode with this rGO electrode, with the feature of a write-once-read-many-times nonvolatile memory effect. By further employing silver nanoparticles and controlling their density at the wrinkled rGO electrode/polymer interface, the optimized device exhibits a high performance nonvolatile memory effect with an ultra-low switching voltage of 0.9 V, high ON/OFF ratio of 1000, and desirable long retention time over 104 s. To the best knowledge, the value of switching voltage is much lower than that of previous related polymer memory devices. This study paves a new way toward ultra-low power manufacturing of non-volatile polymer memory devices.
关键词： interfacial engineering,resistive switching voltage,wrinkle surfaces,nanoparticle decoration,polymer memory devices
更新于2025-09-10 09:29:36