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Effects of Calcination Temperature on Morphology and Structure of CeO2 Nanofibers and their Photocatalytic Activity
摘要： Calcination temperature plays a critical role on morphology and structure of CeO2 nanofibers, thus affecting its photocatalytic activity. CeO2 nanofibers with diameter of 95 nm were successfully fabricated by electrospinning combining with calcination. The calcination temperature was determined by TGA results ranging from 500℃ to 800℃. The morphology and structure of samples obtained with different calcination temperatures, have been characterized by SEM and XRD. Meanwhile, the specific surface area of samples were checked by BET, that was decreased 17 times from 56.3 m2/g to 3.3 m2/g, as the temperature increasing from 500℃ to 800℃. Normally, the higher specific surface area, the more efficiency photocatalytic activity. But it was interesting that the photodegradation rate of methylene blue was increased from 67% to 98% for CeO2 catalyst obtained at 500℃ and 800℃, with 4 times higher kinetic constant reaction rate under UV irradiation for 60 min. It demonstrates that the photocatalytic activity of CeO2 nanofibers catalyst is not directly related to the specific surface area, and increasing the calcination temperature has a positive effect for the photocatalytic efficiency.
关键词： Calcination,Porous Materials,Microstructure,CeO2 Nanofiber,Photocatalysis
更新于2025-09-23 15:23:52
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Facile fabrication of phosphorus-doped g-C3N4 exhibiting enhanced visible light photocatalytic degradation performance toward textile dye
摘要： Phosphorus-doped graphitic carbon nitride (P-g-C3N4) was facilely fabricated by in situ thermal copolymerization of urea and triphenylphosphine source materials. The P-g-C3N4 exhibited an enhanced photocatalytic performance than pristine g-C3N4 counterpart for the degradation of rhodamine B and acid blue D-2BR textile dye under visible light irradiation. X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 adsorption-desorption isotherms, X-ray photoelectron spectra (XPS), and diffuse reflection spectroscopy (DRS) techniques were used to characterized the structure and property of P-g-C3N4 photocatalyst. The phosphorus doping enhanced visible light harvesting and surface area, but also substantially changed the electronic property of g-C3N4 material that could suppress the recombination of photogenerated charge carriers, and thus improved photocatalytic performance.
关键词： Textile dye,Porous photocatalyst,Visible light,Degradation,Phosphorus-doped g-C3N4
更新于2025-09-23 15:23:52
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Structural and optical properties of porous ZnO nanorods synthesized by a simple two-step method
摘要： The porous ZnO nanorods were successfully synthesized by a two-step template free method consisting of a modified hydrothermal approach and subsequent annealing treatment. Additive formaldehyde was adopted in the initial hydrothermal approach. Numerous mesopores with orderly distribution along the c axis apparently appeared in the annealed products. It is suggested that formaldehyde might adsorb in ZnO nanorods during the hydrothermal process and decompose under elevated temperature. The release of the generated gas prompted the formation of the pores. A schematic model was proposed to describe the forming of pores in ZnO nanorods. Further investigation demonstrated that the emission behavior and crystallographic quality may highly depend on the annealing temperature. The intensity ratio of the ultraviolet emission peak and visible emission peak as well as the crystallographic quality fluctuates due to the competition of the forming of pores and annealed temperature. The samples annealed at 450 °C possess high crystallographic quality and large surface area, which may be the suitable candidate for highly effective photocatalyst and ZnO based photoelectric devices.
关键词： Annealing,Porous nanorods,Photoluminescence,ZnO
更新于2025-09-23 15:23:52
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Porous Organic Polymer-Coated Band-Aids for Phototherapy of Bacteria-Induced Wound Infection
摘要： Band-Aids have been widely used for wound care. For most adhesive bandages, however, they have limited capacity to speed up the wound healing process, which in turn may cause serious wound infections. In this study, antibacterial Band-Aids, combining porphyrin based porous organic polymers (POPs) with commercial antibiotics-free Band-Aids, are designed. Under white light irradiation, POP can produce effective photothermal heat, as well as highly reactive oxygen species (ROS), thereby triggering the potent hyperthermia and simultaneous ROS increase on wounds. What's more, white-light is similar with sunlight, which makes POP-based Band-Aids (PBA) ideal wound dressings for wound disinfection.
关键词： wound infection,porous organic polymers,band-aids,white light
更新于2025-09-23 15:23:52
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Influence of Synthesis Conditions on Microstructure and NO2 Sensing Properties of WO3 Porous Films Synthesized by Non-Hydrolytic Sol–Gel Method
摘要： Nanostructured tungsten trioxide porous films were prepared by a non-hydrolytic sol–gel method following the inorganic route in which ethanol and PEG were used as the oxygen-donor and structure-directing reagent, respectively. The effects of aging time of the precursor solution, PEG content, and calcination temperature on the structure, morphology, and NO2 sensing properties of WO3 films were systematically investigated by using the techniques of X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, and gas sensing measurements. The results demonstrated that a series of WO3 films with different microstructures could be obtained by manipulating the synthesis parameters. Furthermore, a suitable synthesis condition of WO3 films for NO2 sensing application was determined.
关键词： NO2,non-hydrolytic sol–gel,WO3,gas sensing,porous films
更新于2025-09-23 15:23:52
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Suppression of Electrochemically Driven Phase Transition in Nanostructured MoS2 Pseudocapacitors Probed Using Operando X-ray Diffraction
摘要： Pseudocapacitors with non-diffusion-limited charge storage mechanisms allow for fast kinetics that exceed conventional battery materials. It has been demonstrated that nanostructuring conventional battery materials can induce pseudocapacitive behavior. In our previous study, we found that assemblies of metallic 1T MoS2 nanocrystals show faster charge storage compared to the bulk material. Quantitative electrochemistry demonstrated that the current response is capacitive. In this work, we perform a series of operando X-ray diffraction studies upon electrochemical cycling to show that the high capacitive response of metallic 1T MoS2 nanocrystals is due to suppression of the standard first-order phase transition. In bulk MoS2, a phase transition between 1T and triclinic phases (LixMoS2) is observed during lithiation and delithiation in both the galvanostatic traces (as distinctive plateaus) and the X-ray diffraction patterns with the appearance of the additional peaks. MoS2 nanocrystal assemblies, on the other hand, show none of these features. We hypothesize that the reduced MoS2 crystallite size suppresses the first-order phase transition and gives rise to solid solution-like behavior, potentially due to the unfavorable formation of nucleation sites in confined space. Overall, we find that nanostructuring MoS2 suppresses the 1T-Triclinc phase transition and shortens Li-ion diffusion path lengths, allowing MoS2 nanocrystal assemblies to behave as nearly ideal pseudocapacitors.
关键词： intercalation pseudocapacitor,pseudocapacitance,MoS2,phase transition suppression,porous electrodes,nanocrystal assemblies,fast charging
更新于2025-09-23 15:23:52
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Modeling of Radiative Properties of Polystyrene Foams Containing IR-Opacifiers
摘要： The addition of opacifiers in foams considerably reduces the radiative thermal conductivity and consequently enhances the insulation performance of the foams. In this work two different methods were developed to calculate the spectral specific extinction coefficient of opacified extruded polystyrene (XPS) foam material. Cell morphology and thermal conductivity of two identical XPS-foams, one opacified with 3 wt% carbon black as opacifier and one without opacifier, were thoroughly characterized. The experimental results were in a good agreement with the theoretical results obtained from two different computing techniques. These methods allow a good prediction of the specific extinction coefficient of arbitrary opacified foam material.
关键词： Radiative transfer,Radiative thermal conductivity,Complex refractive index,Extinction coefficient,Porous materials,Opacifiers
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Karachi, Pakistan (2018.11.1-2018.11.2)] 2018 IEEE 21st International Multi-Topic Conference (INMIC) - Silica Nano-Particulate Coating Having Self-Cleaning and Antireflective Properties for PV Modules
摘要： In this research, silica nanoparticles are coated over the solar PV module glass to acquire super hydrophilic, antireflective and highly transparent surface. Silane precursor mixed with air sprayed on the substrate by aerosol deposition method. Pressure difference between the plasma chamber and the substrate is tuned by the introduction of helium gas, which results in good control over layer thickness and refractive indices. Due to the porous nature and graded index of coated film, the transmittance of glass substrate is increased from 91% to 99.2%. Surface topology of coated film is studied by AFM shows excellent antifogging and super-hydrophilic nature attributed to roughness and nano-porosity of coated film. Moreover, the super-hydrophilic nature endows these coatings with self-cleaning properties, which further enhances the overall efficiency of solar PV modules.
关键词： Antireflective coatings,Super-hydrophilic,Silica nanoparticles,Thin films,solar PV,Aerosol deposition,Nano-porous
更新于2025-09-23 15:22:29
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Precision Plating of Human Electrogenic Cells on Microelectrodes Enhanced with Precision Electrodeposited Nano-Porous Platinum for Cell-Based Biosensing Applications
摘要： Microelectrode Arrays are established platforms for biosensing applications; however, limitations in electrode impedance and cell-electrode coupling still exist. In this paper, the SNR of 25 μm diameter gold (Au) microelectrodes was improved by decreasing the impedance with precision electrodeposition. SEM determined that N-P Pt. microelectrodes had nano-porous structures that filled the insulation cylinders. EIS, CV, and RMS noise measurements concluded that the optimized electrodeposition of N-P Pt. led to a lowered impedance of 18.36 kΩ ± 2.6 kΩ at 1 kHz, a larger double layer capacitance of 73 nF, and lowered RMS noise of 2.08 ± 0.16 μV as compared to the values for Au of 159 kΩ ± 28 kΩ at 1 kHz, 17nF, and 3.14 ± 0.42 μV, respectively. Human motoneurons and human cardiomyocytes were cultured on N-P Pt. devices to assess their biocompatibility and signal quality. In order to improve the cell-electrode coupling, a precision plating technique was used. Both cell types were electrically active on devices for up to 10 weeks, demonstrated improved SNR, and expected responses to precision chemical and electrical stimulation. The modification of Au microelectrodes with nanomaterials in combination with precision culturing of human cell types provides cost effective, highly sensitive, well coupled and relevant biosensing platforms for medical and pharmaceutical research.
关键词： Biosensing,human motoneurons,precision plating of cells,MEA,human cardiomyocytes,nano-porous platinum,precision plating of nanomaterials,microelectrodes,human electrogenic cells
更新于2025-09-23 15:22:29
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Electrical and Photoelectrical Characteristics of с-Si/Porous–Si/CdS Heterojunctions
摘要： Depending on the sizes of the CdS crystallites and silicon pores, electrical and photoelectrical characteristics of c-Si/porous–Si/CdS heterojunctions prepared by electrochemical deposition and anodization, respectively, are studied. The optimal pore size (10–16 nm) is determined, which provides the maximum photoelectric conversion efficiency (7.71%) of heterojunctions.
关键词： porous silicon,heterojunction,anodization,electrochemical deposition
更新于2025-09-23 15:22:29