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An anti-symmetric dual (ASD) Z-scheme photocatalytic system: (ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4) for organic pollutants degradation with simultaneous hydrogen evolution
摘要： An anti-symmetric dual (ASD) Z-scheme ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4 photocatalyst was prepared by isoelectric point and calcination methods. The photocatalytic activity is estimated via degradation of Acid Orange II as a target organic contaminant with simultaneous hydrogen evolution under simulated solar-light irradiation. The prepared ASD Z-scheme ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4 photocatalyst has a high photocatalytic activity, which can be assigned to the enlarged photoresponse range, increased reduction surface and enhanced separation efficiency of photo-induced carriers. Furthermore, the cyclic experiment proves that the prepared ASD Z-scheme ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4 photocatalyst still maintains a high photocatalytic activity within five repetitive cycles. Moreover, the mechanism on photocatalytic degradation of organic pollutants with simultaneous hydrogen evolution caused by ASD Z-scheme ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4 photocatalyst is proposed. It is wished that this study could provide a promising pathway for effective degradation and rapid hydrogen production.
关键词： Simultaneous hydrogen evolution,Organic contaminants,Anti-symmetric dual (ASD) Z-scheme photocatalytic system,ZnIn2S4/Er3+:Y3Al5O12@ZnTiO3/CaIn2S4 composite,Up-conversion luminescence agent,Photocatalytic degradation
更新于2025-11-19 16:51:07
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Investigations on structural, optical and electrical property of ZnO-CuO core–shell nano-composite
摘要： ZnO-CuO core–shell nano-composite was synthesized by two-stage assisted wet-chemical sol-gel method. The nano-composite investigated by X-ray diffraction, ?eld effective scanning electron microscope, UV–visible spectroscopy and Electrical property at different frequency range 100 Hz to 2 MHz and at different temperature. The X-ray diffraction pattern shows poly-crystalline growth of sample, UV–visible spectrum shows higher absorption in ZnO-CuO nano-composite as compare ZnO, which can be understood in vicinity of morphology and heterojunction. The electrical conductivity of nano-composite has been increased with frequency and temperature due to defect available in the sample and thermal excitation of the charges in the sample respectively.
关键词： Nano-composite,Sol–gel,Core–shell,AC conductivity
更新于2025-11-14 17:28:48
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Effect of BaZr <sub/>0.4</sub> Ti <sub/>0.6</sub> O <sub/>3</sub> addition on electrical and magnetic properties of multiferroic (1-x)BiFeO <sub/>3</sub> -xBaTiO <sub/>3</sub> ceramics
摘要： The 0.75((1-x)BiFeO3-xBaTiO3)-0.25BaZr0.4Ti0.6O3 or 0.75(BFO-BTO)-0.25BZT ceramics (x = 0.23–0.27) have been prepared by solid state reaction method to studied the relationship between phase formation, dielectric and magnetic properties. The results found that the phase formations of calcined BFO-BTO and BZT powders are distorted rhombohedral and cubic structure, respectively. Moreover, the addition of BZT in BFO-BTO-BZT ceramics affected to the phase change dramatically according to increasing of BZT content compared to calcined BFO-BTO powders. All the samples showed cubic perovskite structure. The room temperature dielectric properties decreased with increasing of BTO content, the highest dielectric constant with low losses observed in 0.75(0.77BFO-0.23BTO)-0.25BZT ceramic. Furthermore, the ceramics displayed maximum dielectric constant temperature (Tm) above 360 °C. Interestingly, all ceramic compositions exhibited typical ferromagnetic hysteresis loop and the highest remanent magnetization observed in 0.75(0.77BFO-0.23BTO)-0.25BZT ceramic.
关键词： composite,dielectric properties,ferromagnetic hysteresis loops,BFO-BTO,BZT
更新于2025-11-14 17:28:48
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Enhanced piezoelectricity of a PVDF-based nanocomposite utilizing high-yield dispersions of exfoliated few-layer MoS2
摘要： Piezoelectric polymer composite ?lms have attracted extensive attention due to their comprehensive characteristics such as low cost, good ?exibility, mechanical property and excellent processability. Among the known polymers, poly (vinylidene ?uoride) (PVDF) is an ideal piezoelectric polymer because the β-crystalline form of PVDF has the highest polarization per unit cell. However, initial PVDF mostly su?ers from the lack of a β phase, restricting its potential applications. Few-layer MoS2 is predicted to be strongly piezoelectric owing to the opposite orientations of adjacent atomic layers. In this work, we report an e?cient approach to enhance the piezoelectric property of PVDF-based nanocomposites by combining few-layer MoS2 with PVDF. The product yield for few-layer MoS2 reached a value as high as 83.3% via a unique liquid-exfoliation technique. For a few-layer MoS2/PVDF composite ?lm with 1 wt.% few-layer MoS2, a high piezoelectric performance enhancement of 360% was achieved compared with the initial PVDF ?lm. In addition, due to the intrinsic lubrication of MoS2, the highest elongation of the piezoelectric composite ?lm was found to be four times higher than that of the pure PVDF ?lm.
关键词： Composite,Film,Piezoelectric performance,Few-layer
更新于2025-11-14 17:28:48
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Structure-design strategy of 0–3 type (Bi0.32Sr0.42Na0.20)TiO3/MgO composite to boost energy storage density, efficiency and charge-discharge performance
摘要： A novel 0–3 type (Bi0.32Sr0.42Na0.20)TiO3/MgO composite is investigated in this work, which possesses a high stored energy storage density ws?2.50 J/cm3, recoverable energy storage density WR?2.09 J/cm3 with high efficiency η?84% under low electric field (20 kV/mm). The excellent performance is owning to the increase of breakdown strength (BDS) value and the intrinsic mechanism for enhanced BDS value by MgO incorporation is disclosed by numerical simulations (COMSOL). Moreover, the studied composite exhibits excellent charge-discharge performance, the current density (CD) and power density (PD) are 1671 A/cm2 and 150 MW/cm3, respectively, which are much superior to that of other ceramics. Besides, most of the stored energy is discharged within ?0.15 μs via charge-discharge tests. This work not only provides a novel technique to designing bismuth-based ceramic capacitors with simultaneously high Wd, η and excellent charge-discharge performance, but also deepens the understandings of the role for the metallic oxide in the composite.
关键词： 0–3 Composite,Energy storage,Numerical simulations,Charge-discharge,Lead-free
更新于2025-11-14 17:28:48
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Rapid gas-liquid detonation synthesis of core-shell structural graphite coated TiO2 nanoparticles
摘要： Here we demonstrate a simple, rapid for the controlled synthesis of core-shell structural graphite coated TiO2 nanoparticle (TiO2@G), which are directly prepared by detonation chemical decomposition of the gas-liquid mixture of CH4, O2, C6H6 and TiCl4 in milliseconds. Various techniques, including XPS, TEM, XRD and Raman were employed to investigate the products. It is found that the sphere, good disperse mixed crystal TiO2 nanoparticles with crystal size of 10–30 nm were coated with thick graphite layers. Based on Zeldovich Neuman-Doring (ZND) model, the detonation synthesis mechanism of core-shell structure TiO2@G is discussed. This rapid synthesis method can be extended to the preparation of other core-shell materials.
关键词： Gas-liquid detonation,Graphite coated TiO2,Core-shell structure,Composite materials,Formation mechanism
更新于2025-11-14 17:04:02
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Laser-induced synthesis and photocatalytic properties of hybrid organic–inorganic composite layers
摘要： A laser-based method was developed for the synthesis and simultaneous deposition of multicomponent hybrid thin layers consisting of nanoentities, graphene oxide (GO) platelets, transition metal oxide nanoparticles, urea, and graphitic carbon nitride (g-C3N4) for environmental applications. The photocatalytic properties of the layers were tested through the degradation of methyl orange organic dye probing molecule. It was further demonstrated that the synthesized hybrid compounds are suitable for the photodegradation of chloramphenicol, a widely used broad-spectrum antibiotic, active against Gram-positive and Gram-negative bacteria. However, released in aquatic media represents a serious environmental hazard, especially owing to the formation of antibiotic-resistant bacteria. The obtained results revealed that organic, urea molecules can become an alternative to noble metals co-catalysts, promoting the separation and transfer of photoinduced charge carriers in catalytic composite systems. Laser radiation induces the reduction of GO platelets and the formation of graphene-like material. During the same synthesis process, g-C3N4 was produced, by laser pyrolysis of urea molecules, without any additional heat treatment. The layers exhibit high photocatalytic activity, being a promising material for photodegradation of organic pollutants in wastewater.
关键词： transition metal oxide nanoparticles,urea,photocatalytic properties,hybrid organic–inorganic composite layers,graphene oxide,graphitic carbon nitride,methyl orange,laser-based synthesis,chloramphenicol
更新于2025-11-14 17:04:02
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A molecular-based design of RGO/TiO2-PAM composite flocculant with photocatalytic self-degrading characteristics and the application of the oil sand tailings flocculant
摘要： Polymer flocculation technology has a very broad application in the flocculation industry of oil sand tailings at present. Nevertheless, the most commonly used commercial polyacrylamide flocculant has problems of low flocculation efficiency and secondary pollution. In this paper, we proposed an organic-inorganic composite flocculant with self-degrading properties for the flocculation treatment of oil sand tailings, which was prepared by photocatalytic surface initiation technique. Further, the functional groups of the materials before and after polymerization composites were characterized by infrared spectrum to explore the polymerization mechanism, the structure was observed by transmission electron microscope, and the molecular weight of polyacrylamide was measured by gel permeation chromatography. Then, the flocculation performance was characterized by the flocculation experiment (tested with simulated oil sand tailings). Subsequently, the flocculation mechanism was explored by testing the zeta potential of the organic-inorganic composites and analyzing images of sediment observed by transmission electron microscope and atomic force microscope. Finally, the test of self-degradation performance was carried out under illumination. Based on the above experiments, the following conclusions were obtained. First, the structural characterization results indicate the polymerization mechanism is that under the condition of light, the surface of the inorganic photocatalyst generates free radicals to initiate the radical polymerization of the monomers, so that the monomers successfully grow on the surface of the inorganic particles into comb structure. And then, the flocculation experiment shows that reduced graphene oxide/titanium dioxide-polyacrylamide(2:40) has the best flocculation effect, of which the supernatant transmittance is 21.4 higher and the sedimentation ratio is 8.9% higher than those of the commercial polyacrylamide. The reason for its excellent flocculation performance is that the zeta potential of the organic-inorganic composite increases, reducing repulsion of particles and flocculant molecules, simultaneously, the formed comb structure is beneficial to the expansion of the polymer chain and increases the contact area, thereby improving the flocculation effect. Ultimately, the degradation results indicates that the new organic-inorganic composite had good degradation effect, with the degradation rate up to 75.9% within 4 hours. Therefore, this work has made great contributions to solving the oil sand tailings pollution field.
关键词： Flocculant,Oil sand tailings,Photocatalytic Self-degrading,Organic-inorganic composite,Comb structure
更新于2025-11-14 17:03:37
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Visible light-induced oxidation of aqueous arsenite using facile Ag2O/TiO2 composites: Performance and mechanism
摘要： Conversion of aqueous arsenite [As(III)] to less toxic arsenate [As(V)] is a critical step for the arsenic pollution remediation. In this study, Ag2O/TiO2 composites synthesized via the pH-induced precipitation method were employed into the photocatalytic oxidation of As(III) under visible light irradiation. X-ray diffraction, transmission electron microscope and X-ray photoelectron spectroscopy analysis verified the formation of Ag2O/TiO2 heterostructures. Compared to pure Ag2O and TiO2, the 30% Ag2O/TiO2 composite exhibited much higher photochemical reactivities for the oxidation of As(III) under visible light irradiation. Under the optimal conditions [pH=4.0, the photocatalyst dosage being 0.3 g L-1 and initial As(III) concentration being 10 mg L-1], the oxidation and removal percent of As(III) was 60.7% and 83.0% after reaction for 120 min, respectively. Moreover, the formation of Ag(0) over the surface of Ag2O by photo-induced electrons contributed to the high stability of Ag2O/TiO2 composite. It was also found that photo-generated holes and superoxide radicals played the predominant roles in the As(III) oxidation. The improved photocatalytic activities were attributed to the formation of the hetero-junctions between Ag2O and TiO2, the strong visible light absorption, and the high separation efficiency of photo-generated electron-hole pairs resulted from the Schottky barriers at the Ag-Ag2O interface.
关键词： visible light,arsenite oxidation,Ag2O/TiO2 composite,photocatalytic
更新于2025-11-14 17:03:37
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Luminescent Composites Based on Tetrafluoroethylene Copolymer Porous Films Produced by the Diffusion Embedding of Semiconductor Nanoparticles in a Supercritical Medium
摘要： A method for creating film composites based on a new material—a fibrous copolymer of tetrafluoroethylene and vinylidene fluoride—using the diffusion embedding of ready-made nanoparticles into a porous matrix in a supercritical (SC) carbon dioxide medium is developed. The method of cold or hot pressing of impregnated porous films was used at the final stage of creation of such composites. The peculiarities of the effect of the supercritical fluid treatment of porous copolymer films on the surface structure of pressed films are discussed. Luminescent composites with semiconductor nanoparticles of cadmium selenide and nanocrystalline silicon are obtained; their radiation covers a range of 500–1000 nm. The change in the luminescence properties of the resulting nanocomposites under the action of excitation laser radiation at 405 nm is demonstrated.
关键词： cadmium selenide,film composite,fibrous matrix,luminescent properties,diffusion embedding,nanocrystalline silicon
更新于2025-11-14 15:30:11