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Ag3PO4 modified phosphorus and sulphur co-doped graphitic carbon nitride as a direct Z-scheme photocatalyst for 2, 4-dimethyl phenol degradation
摘要： Very recently, hybrid photocatalysts are gaining importance due to their unique and enhanced photocatalytic activity. In precedent study, we have successfully prepared Ag3PO4 (AP) and P and S co-doped g-C3N4 (PSGCN) based AP/PSGCN photocatalyst via facile deposition-precipitation method. The P and S co-doped g-C3N4 was prepared via thermal poly-condensation using hexachlorotriphosphazene (HCCP) and thiourea as precursors. The photocatalysts were characterized by X-ray diffraction pattern (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) and ultraviolet–visible diffuse reflectance spectroscopy (UV–Vis DRS). The thickness of AP/PSGCN was less than 9.0 nm. The zeta potential and Tyndall effect experiments validated the formation of well dispersed suspension of AP/PSGCN in water. The co-doping resulted in lowering of optical band gap of g-C3N4. The Tyndall effect experiments ascertained the formation of well dispersed suspension of AP/PSGCN. The photoluminescence and electrochemical impedance analysis confirmed reduction in recombination of photogenerated electron and hole pairs. The photodegradation of 2,4-dimethyl phenol (DMP) followed pseudo first order kinetics. The enhanced photocatalysis was due to direct Z-scheme mechanism. Hydroxyl and superoxide radicals were the two main reactive species during DMP degradation. The COD, HPLC and LC-MS investigations ascertained mineralization of DMP. AP/PSGCN displayed high stability and recycle efficiency significant for ten catalytic cycles.
关键词： DMP,Ag3PO4,P and S Co-doped g-C3N4,Nanocomposite,Z-scheme photocatalysis
更新于2025-09-23 15:22:29
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Effect of copper doping on the crystallization behavior of TiSbTe for fast-speed phase change memory
摘要： In this study, Ti-Sb-Te (TST) alloy doped with Cu has been proposed to enhance the phase change and electrical properties of TST. The formation of Cu-Te bond was suggest to be responsible for the improved thermal stability of the Cu0.28(Ti0.09Sb0.38Te0.53)0.72 (Cu0.28TST) film. Cu0.28TST -based phase change memory cell can be triggered by a 5 ns electric pulse. Such fast speed was asscribed to its growth-dominated crystallization mechanism and the precipitation of Sb in the crystallization process. Furthermore, an endurance cycles up to 105 could be achieved in the memory cell.
关键词： nanocomposite,thermal stability,rapid transition,thin film
更新于2025-09-23 15:22:29
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Integrated adsorption and photocatalytic degradation of volatile organic compounds (VOCs) using carbon-based nanocomposites: A critical review
摘要： Volatile organic compounds (VOCs) are harmful for human and surrounding ecosystem, and a great number of VOC abatement technologies have been developed during the past few decades. However, the single method has some problems such as high energy consumption, unfriendly environment, and low removal efficiency. Recently, the integration of adsorption and photocatalytic degradation of VOCs is considered as a promising one. Carbon material, with large surface area, high adsorption capacity, and fast electron transfer ability, is widely used in integrated adsorptive-photocatalytic removal of VOCs. It is thus crucial to digest and summarize recent research advances in carbon-based nanocomposites as the adsorbent-photocatalyst for VOC removal. To satisfy this need, this work provides a critical review of the related literature with focuses on: (1) the advantages and disadvantages of various carbon-based nanocomposites for the applications of VOC adsorption and photocatalytic degradation; (2) models and mechanisms of adsorptive-photocatalytic removal of VOCs according to the material properties; and (3) major factors controlling adsorption-photocatalysis processes of VOCs. The review is aimed to establish the "structure-property-application" relationships for the development of innovative carbon-supported nanocomposites and to promote future research on the integrated adsorptive and photocatalytic removal of VOCs.
关键词： Modeling,Photocatalytic degradation,VOC abatement,Carbon-based nanocomposite,Adsorption
更新于2025-09-23 15:21:21
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Preparation and luminescent properties of mesoporous (SBA-15)-Eu2O3 nano materials
摘要： The CH3-(SBA-15) and (SBA-15)-Eu2O3 host-gust nanocomposite materials were synthesized by post-synthesis method, ultrasonic synthesis method (UM) and ultrasonic assisted synthesis methods (UAM). The X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscope (TEM) analysis and nitrogen adsorption-desorption method were used to observe the structure, the surface morphology and the chemical composites of the prepared products. The luminescent properties, and the luminescent intensity of the samples were studied by excitation and emission spectra. The results showed that, for the (SBA-15)-Eu2O3 composite materials, the hexagonal pore structure of the SBA-15 molecular sieve was maintained. The luminescent intensity of the UM sample was about 6 times higher than that of the mechanical mixture of SBA-15 and nano-Eu2O3 (5 wt %). The excitation spectrum intensity was 2 times higher than that of the mechanical mixture.
关键词： (SBA-15)-Eu2O3,Luminescence,SBA-15 molecular sieve,Trimethyl chlorosilane,Host-gust nanocomposite material
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Fluctuations of the emission characteristics of multi-tip field cathodes
摘要： Report presents a complex experimental study of the fluctuations in the emission characteristics of multi-tip field cathodes based on composites "disordered carbon nanotubes in a polymer matrix". The objects of the study: correlation of the glow patterns of the field emission projector with the level of the macroscopic emission current, emission sites activity, distribution of the current load on the emission sites, field enhancement factor of the individual emission sites, dependence of the current-voltage characteristics and effective emission parameters on the voltage and vacuum levels, formation of a calibration grid on the SK-diagram, modeling of the adsorption/desorption processes on the emitter surface.
关键词： emitter surface analysis,field emission images,current fluctuation,nanocomposite,field emission,carbon nanotubes,IVC
更新于2025-09-23 15:21:21
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[IEEE 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Kyoto, Japan (2018.7.9-2018.7.13)] 2018 31st International Vacuum Nanoelectronics Conference (IVNC) - Experimental Definition of k-power of Pre-Exponential Voltage Factor for LAFE
摘要： In this work we used the possibilities of a comprehensive research methodology for LAFE. To determine the degree of the voltage in the pre-exponential factor, we used the IVC differentiation method and the method of minimization trend residue by variation Fowler-Nordheim coordinates. The method proved to be very sensitive to IVC bends and can serve as a characteristic for the homogeneity of LAFE arrays.
关键词： k-power,nanocomposite,field emission,carbon nanotubes,differentiation of current-voltage charateristics
更新于2025-09-23 15:21:21
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Effect of Deposition Pressure, Nitrogen Content and Substrate Temperature on Optical and Mechanical Behavior of Nanocomposite Al-Si-N Hard Coatings for Solar Thermal Applications
摘要： Hard and optically transparent nanocomposite Al-Si-N thin films were deposited using DC magnetron sputtering at different process parameters. There was a significant effect of these parameters on the film properties affecting its mechanical and optical behavior. The nitrogen content or pressure, deposition pressure and substrate temperature strongly influence the phase formation which governs the hardness and optical transparency of the coating. Hardness was measured between 18 and 30 GPa. The band gap could be varied in the range of 3.8-4.2 eV by varying nitrogen pressures in the chamber during deposition. The films showed (0-80)% transparency in UV and visible region depending on the sputtering conditions.
关键词： mechanical behavior,optical coating,nanocomposite hard coatings
更新于2025-09-23 15:21:21
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Facile synthesis approach for core-shell TiO2–CdS nanoparticles for enhanced photocatalytic H2 generation from water
摘要： With the ambition to design a cost-effective and highly stable photocatalyst with improved photocatalytic activity towards H2 generation by water splitting, herein we report a two-step facile synthesis approach for core-shell structure of TiO2-CdS nanocomposites. The synthesized photocatalysts are comprehensively characterized by SEM, XRD, BET, UV-vis DRS, Photoluminescence and XPS to investigate the morphological, crystalline, structural, optical properties and surface analysis. The photocatalytic activity is evaluated by measuring the ability of TiO2-CdS to generate H2 gas by water splitting in the presence of hole scavengers under simulated solar light at AM 1.5G conditions. Our optimized sample TiO2-CdS (3:2) exhibited an enhanced photocatalytic activity by generating 954 μmol g-1 h-1 of hydrogen which is ~1.4 and ~1.7 times higher than pure CdS nanoparticles and pure TiO2, respectively. The optimized sample achieved an apparent quantum efficiency of 3.53% along with good stability by generating a similar amount of H2 for 40 consecutive hours. The enhanced photocatalytic activity and stability of the core-shell TiO2-CdS nanocomposite is attributed to the broader solar spectrum absorption, efficient photo-induced charge separation on the interface of TiO2-CdS due to the formation of heterojunction and high surface area with a large fraction of mesopores.
关键词： Photocatalytic H2 generation,Core-Shell TiO2-CdS nanocomposite,hydrothermal approach,CdS nanoparticles,Heterojunction
更新于2025-09-23 15:21:21
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[IEEE 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Odessa, Ukraine (2018.9.4-2018.9.7)] 2018 9th International Conference on Ultrawideband and Ultrashort Impulse Signals (UWBUSIS) - Influence of Dissipations in the Semiconductor Layers on the Properties of Hybrid Surface Waves at the Interface Between Porous Nanocomposite and Hypercrystal
摘要： Dispersion properties of surface electromagnetic waves at the plane interface of nanocomposite made of semiconductor inclusions and a hypercrystal under different electron collision frequency and electron concentration are studied. Effective medium theory was applied in order to describe the contacting materials. The nanocomposite as well as the hypercrystal includes semiconductor layers made of n-InSb. Temperature models for concentration of charge carriers as well as mobility of charge carriers are applied to describe the physical properties of n-InSb material. On raising the temperature, the layers of n-InSb and, consequently, contacting composites, transform from a weakly dissipative materials to highly dissipative in the terahertz and optical frequencies. It is shown, that influence of dissipations in the semiconductor material results in the arising of additional surface waves branches, standard surface plasmon polaritons and Dyakonov surface waves, changes in frequency domains, angular existence domains, and penetration depth. Moreover, Dyakonov surface wave’s branches can exist in the ranges where they are prohibited in the case of lossless materials.
关键词： surface waves,nanocomposite,semiconductor,metamaterial
更新于2025-09-23 15:21:21
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Comparative study of structural, magnetic and dielectric properties of CoFe2O4 @ BiFeO3 and BiFeO3@ CoFe2O4 core-shell nanocomposites
摘要： Nano-sized CoFe2O4 (CFO), BiFeO3 (BFO) and their core-shell composites BFO@CFO and CFO@BFO were synthesized by chemical co-precipitation method. X-ray di?raction pattern con?rmed the crystallinity and phase formation of bare CFO, BFO and their core-shell composites. Morphology and core-shell nature of these nano-particles is justi?ed by ?eld emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM). Magnetization curve showed the weak ferromagnetic behaviour of BFO. Typical ferrimagnetic behaviour is shown by bare CFO and core-shell nanocomposites. The value of maximum magnetization, remanence magnetization and coercivity of CFO@ BFO were found to be greater than the BFO@ CFO. Also, CFO@ BFO showed the highest value of dielectric constant in the frequency range of 104–106 Hz. Dielectric constant versus temperature curve of BFO and core-shell composites exhibit incongruity close to the anti-ferromagnetic transition temperature (370 °C) of BFO indicating presence of magnetoelectric (ME) coupling.
关键词： Multiferroic,Nanocomposite,Core-shell,Co-precipitation
更新于2025-09-23 15:21:21