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A high-performance room temperature methanol gas sensor based on alpha-iron oxide/polyaniline/PbS quantum dots nanofilm
摘要： A high-performance room temperature methanol gas sensor based on alpha-iron oxide/polyaniline/lead sulfide quantum dots (α-Fe2O3/PANI/PbS QDs) nanofilm was demonstrated in this paper, among which the α-Fe2O3 was an urchin-shaped hollow microsphere. The sensing film was fabricated on an epoxy substrate with interdigital electrodes via successive ionic layer adsorption and reaction technique. The prepared α-Fe2O3/PANI/PbS QDs nanocomposite was examined by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, scanning election microscopy and Fourier transform infrared spectrum. The methanol sensing performances of the α-Fe2O3/PANI/PbS QDs film sensor were investigated against methanol from 10 to 100 ppm at room temperature. The experimental results indicated that the methanol sensor in this work had an excellent response, outstanding selectivity and good repeatability at room temperature. The underlying sensing mechanism of the α-Fe2O3/PANI/PbS QDs film toward methanol was ascribed to a series of interactions and changes on the surface of thin films, which make their resistance change greatly. Larger surface area and much more active adsorption sites also played an important role.
关键词： Methanol gas sensor,Room temperature,Successive ionic layer adsorption and reaction,Hydrothermal method,α-Fe2O3/PANI/PbS QDs
更新于2025-11-14 17:15:25
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A new solar hybrid clean fuel-fired distributed energy system with solar thermochemical conversion
摘要： This paper proposes a new solar hybrid clean fuel-fired distributed energy system to increase the system thermodynamic efficiency and save fossil fuel, in which solar energy is upgraded into high-level chemical energy of syngas (H2 and CO) by integrating the solar-driven methanol decomposition based thermochemical conversion. Solar energy, in the form of chemical energy of the generated syngas, is steadily stored and utilized to drive the distributed energy system to generate power, heat and cooling. The double-axis tracking parabolic trough solar collector is deployed to the proposed system to reduce the cosine loss of solar energy. The incorporation of the solar thermochemistry and double-axis solar concentrator technologies leads to a significant improvement in the solar energy utilization efficiency and the off-design performances under varying solar irradiations. With the integration of solar energy utilization and tri-generation, the proposed system achieves a high net solar-to-electric efficiency, 24.66%, and results in high primary energy ratio, 83.86%, exergy efficiency, 38.81%, and carbon emission saving rate, 51.43%. The proposed system is deployed to an office building to study the operation strategies and annual thermo-economy performances, and competitive off-design performances and economy performances are achieved. The research findings open up a new avenue towards the efficient utilization modes of clean fuel and solar energy.
关键词： Distributed energy system,Solar fuel,Solar thermochemistry,Methanol decomposition,Tracking strategy
更新于2025-09-23 15:23:52
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High-temperature mid-infrared absorption spectra of methanol (CH3OH) and ethanol (C2H5OH) between 930 and 1170?cm-1
摘要： A methodology was recently developed with a broad-tuning, rapid-scan external-cavity quantum-cascade-laser in conjunction with shock tube facilities to measure the high-temperature mid-infrared absorption spectra of gaseous molecules. This technique is deployed to measure the cross section profiles in the C-O stretching band for methanol (CH3OH) and ethanol (C2H5OH) between 930 and 1170 cm-1. Methanol spectra are presented from 620 to 1304K between 0.98-3.30 atm with distinctive P, Q, and R branches of the ν8 vibrational band. At elevated temperatures, the emergence of hotbands and high-J ro-vibrational transitions are clearly observed. The absorption cross sections of ethanol are measured from 296 to 1018K between 0.90-3.27 atm. The peak strength decreases with temperature, with the peak location shifting to lower wavenumbers. These measurements are compared with existing empirical models, illustrating a strong need for the development of a high-temperature spectroscopic database.
关键词： Absorption spectra,Ethanol,Mid-infrared,High-temperature,Shock tube,Methanol
更新于2025-09-23 15:23:52
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Determination of adulterated gasoline using fluorescence emission-excitation matrices and multivariate calibration
摘要： Methanol gasoline, known as a new energy, has a certain degree of damage to automobile. The aim of this work was to identify and quantify the methanol in methanol gasoline using three-dimensional fluorescence spectroscopy technique combined with second order chemometric methods. Parallel factor analysis (PARAFAC) and self-weighted alternating trilinear decomposition (SWATLD) methods were used to analyse artificial samples. However, the obtained results by PARAFAC were not satisfactory. On the other hand, excellent prediction results were obtained when SWATLD model was applied, with recovery rate between 98.7 and 102.8%, and between 97.4 and 101.9% for two and three factor respectively. In order to verify the accuracy of the method, four real samples were predicted using SWATLD model with RMSEP between 0.1 μg/mL and 0.23 μg/mL.
关键词： SWATLD,Methanol gasoline,PARAFAC,Excitation-emission matrix fluorescence
更新于2025-09-23 15:23:52
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Ultrafast methanol sensing properties of nano-spindle like In2O3 hierarchical structures with oxygen vacancies
摘要： Unique nano-spindle like In2O3 hierarchical structures have been successfully prepared using a simplified solvothermal method. The micromorphology and crystalline structure of the as-obtained are characterized by SEM, TEM, and XRD. Morphology analysis reveals that the nano-spindle like In2O3 hierarchical structures are composed of numerous ordered nanorods. The optical properties of the samples are also studied, and it is confirmed that the presence of a large amount of oxygen vacancies in the as-synthesized samples. The as-synthesized nano-spindle like In2O3 hierarchical structures are used for the detection of the methanol gas. The sensing properties of the as-manufactured sensor are carefully discussed and the sensor shows outstanding methanol sensing performance, especially ultrafast response time (<1 s). The sensing mechanism is also discussed. This work offers the possibility to manufacture low-cost, high-performance methanol sensor based on the as-synthesized nano-spindle like In2O3 hierarchical structures.
关键词： Oxygen vacancies,Methanol sensing performance,Hierarchical structures,Nano-spindle like In2O3
更新于2025-09-23 15:22:29
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Production of Methanol from Aqueous CO <sub/>2</sub> by Using Co <sub/>3</sub> O <sub/>4</sub> Nanostructures as Photocatalysts
摘要： In this work, we report for the first time the photocatalytic activity of Co3O4 nanostructures for the reduction of aqueous CO2 to methanol (MeOH). This could be considered a simple example of artificial photosynthesis. The photocatalysis experiments were developed under simulated solar light of 100 mW/cm2 and without using any sacrificial agent. To carry out this study, nanostructured mixed valence cobalt oxide (Co3O4) powders, with porous nanoparticle aggregates of different morphologies, have been prepared by two synthesis methods. The characterization of structural (PXRD, XPS, SEM, and TEM) and optical (UV-vis-NIR, Raman, and FT-IR) properties, magnetization curves, and surface area (BET) was accomplished.
关键词： Co3O4,photocatalysis,artificial photosynthesis,CO2 reduction,nanostructures,methanol
更新于2025-09-23 15:22:29
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Thermal and Photocatalytic Reactions of Methanol and Acetaldehyde on Pt-Modified Brookite TiO <sub/>2</sub> Nanorods
摘要： The influence of adding Pt on the catalytic and photocatalytic activity of monodispersed brookite phase TiO2 (B-TiO2) nanorods (NRs) was investigated. Pt was deposited on the NRs by photo-deposition in solution and the Pt-modified NRs were characterized using XPS, STEM, and LEIS. The thermal and photocatalytic activity of the Pt-modified NRs were then evaluated using temperature-programmed desorption (TPD) in ultra-high vacuum (UHV). It was found that while Pt primarily acted as a site blocker for thermal reactions, Pt also acted as a recombination center for photogenerated electrons and holes, resulting in suppressed photocatalytic activity. Upon pretreatment with O2, however, the Pt-modified NRs exhibited enhanced photoactivity, indicating that adsorbed oxygen prevents electron-hole recombination by reacting with photogenerated conduction band electrons from the B-TiO2 to produce stable superoxide species on the Pt surface deposits. These results clearly demonstrate how the dynamics of charge carriers at the oxide surface may be altered by metal deposits such as Pt, as well as by the presence of adsorbed species on the metal surface.
关键词： brookite,acetaldehyde,photo-oxidation,TiO2,TPD,UHV,methanol,Pt
更新于2025-09-23 15:21:21
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Role of Pt Loading in the Photocatalytic Chemistry of Methanol on Rutile TiO2(110)
摘要： As a cocatalyst, Pt is well-known for accepting photoexcited electrons and lowering the overpotential of hydrogen production in photocatalysis, being responsible for the enhanced photocatalytic efficiency. Despite the above existing knowledge, the adsorption of reactants on the Pt/photon-absorber (for example, Pt/TiO2) interface, a prerequisite to understand the photocatalytic chemistry, is extremely difficult to investigate mainly due to the complexity of the powdered material and solution environment. Combining ultrahigh vacuum and well-ordered single crystals, we study the photocatalytic chemistry of methanol on Pt loaded rutile TiO2(110) using temperature-programmed desorption (TPD) and ultraviolet photoelectron spectroscopy (UPS). Despite the same photocatalytic chemical products, i.e., formaldehyde and surface hydrogen species, as on Pt-free TiO2(110), the subsequent chemistry of surface hydrogen species and the photocatalytic reaction rate are much different. The bridging hydroxyls desorb as water molecules around 500 K on Pt-free TiO2(110) surface, by contrast, this desorption channel disappears completely and water and molecular hydrogen desorb at much lower temperature (<300 K) after Pt deposition, which can prevent the recombination of hydrogen species with formaldehyde. More importantly, methanol dissociates into methoxy at the Pt/TiO2(110) interface, which is crucial in the photocatalytic chemistry of methanol on TiO2 surfaces since methoxy is a more effective hole scavenger than methanol itself. The photocatalytic chemical reaction rate is increased by nearly one order of magnitude after 0.12 monolayer Pt deposition. This work suggests that Pt loading can promote the dissociation of methanol into methoxy and lower the desorption barrier of molecular hydrogen, which may work cooperatively with separating photoexcited charges to enhance the photocatalytic efficiency. Our work implies the importance of the cocatalysts in affecting the surface structure and adsorption of reactants and products and then improving the photoactivity, in addition to the well-known role in charge separation.
关键词： Titanium Dioxide,Charge Separation,Pt Cocatalyst,Hydrogen Production,Methanol to Methoxy Conversion
更新于2025-09-23 15:21:21
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Preparation and Characterization of Metal-Organic Frameworks and its Composites Eu <sub/>2</sub> O <sub/>3</sub> @[Zn <sub/>2</sub> (bdc) <sub/>2</sub> dabco] (ZBDh) via Pulsed Laser Ablation in Flow Liquid
摘要： This work reports the compounds of [Zn2(bdc)2dabco] (ZBDh) and [Zn2(bdc)2dabco] (ZBDt) and the composite Eu2O3@[Zn2(bdc)2dabco](ZBDh) synthesized by pulsed laser ablation in flowing liquid. At an appropriate reactants concentration of reactants, the phase ZDBh transforms into phase ZDBt by an increase of the irradiation time from 4 to 40 mins. The results show that the Eu2O3 nanoparticles with an average size of 3.17 nm are uniformly distributed among the crystal and the BET specific surface area of the composite Eu2O3@[Zn2(bdc)2dabco] (ZBDh) is 1621 m2/g, which is larger than that of compound [Zn2(bdc)2dabco] (ZBDh). Moreover, the composite Eu2O3@[Zn2(bdc)2dabco](ZBDh) can emit very intense characteristic fluorescence at 613 nm of Eu3+ ion under ultraviolet radiation and can be used for detecting of methanol molecules in fluorescence sensing because of its fluorescence intensity at 613 nm is sensitive to the content of methanol in solvent.
关键词： pulsed laser ablation,metal-organic frameworks,Eu2O3 nanoparticles,fluorescence sensing,methanol detection
更新于2025-09-23 15:21:01
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Ternary PtNiCu self-assembled nanocubes for plasmon-enhanced electrocatalytic hydrogen evolution and methanol oxidation reaction in visible light
摘要： The strong interaction among metal components results in the change of the electronic structure (e.g. d-band energy level) of noble metal-based alloy structures which enables the increase of catalytic activity. In this paper, self-assembled ternary PtNiCu and binary PtCu alloy nanocubes are synthesized by a one-pot high-temperature chemical reduction method. The growth mechanism of the alloy is investigated. The alloy is applied to visible light-assisted electrocatalytic hydrogen production and methanol oxidation. The ternary PtNiCu alloy exhibits superior catalytic performance (a minimum over potential of 15 mV at a current density of 10 mA cm-2, a Tafel slope of 24.1 mV/dec, and more excellent mass specific activity under visible light irradiation about 3.3 A mgPt -1), because of its regular morphology, more surface active sites, and more intense interaction between metal elements. Especially the localized surface plasmon resonance effect of Cu largely increases the electron density (photoelectric effect) on Pt under illumination, thereby further improves the photo-assisted hydrogen production and methanol catalytic oxidation performance. The results will promote efficient and accurate electrocatalysis process, paving new way for a brighter further in rational design of ternary plasmonic electrocatalysts and photoelectrocatalysis field.
关键词： Methanol oxidation reaction,Photoelectrocatalysis,Hydrogen evolution reaction,Ternary PtNiCu alloy
更新于2025-09-23 15:21:01