- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
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
-
Enhanced optoelectronic performance of plasma electrolytic oxidized monocrystalline silicon using rGO incorporation
摘要： rGO/SiO2 composite coating was successfully prepared by plasma electrolyte oxidation (PEO) process on monocrystalline silicon (mc-Si) substrate. Investigating the effect of rGO incorporation into the SiO2 coating revealed that the addition of rGO leads to a significant increase in the photo-trapping ability due to the high specific surface area and excellent electron transfer efficiency. The PL intensity of the composite sample was found to decrease, which signified the suspension of the electron-hole pairs’ recombination. As a result, the photocurrent gain of the composite coating enhanced about 5.5 times. Likewise, the time-response switching featured an over two-fold increase for the rGO/SiO2 coating, impressively.
关键词： Semiconductors,Plasma electrolyte oxidation,Optoelectrical properties,Composite materials,rGO/SiO2 composite
更新于2025-09-23 15:23:52
-
An eco-friendly method to enhance optical and electrical properties of conducting polymers by means of carboxymethyl cellulose
摘要： In this work, an eco-friendly method is proposed for the electro-synthesis of conductive polymers with superior optical and electrical properties by means of CMC in aqueous media. For this purpose, an aqueous dispersion of a water-insoluble monomer namely 4-amino-N-[2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl]benzamide (TPB) has been prepared by attaching it to CMC via hydrogen bonds and the conductive composite film (PTPB–CMC) has been obtained by electropolymerization. The TPB monomer has been chosen to interact with the CMC via hydrogen bonds which ensures to obtain dispersion with the CMC and also increase the compatibility of its polymer in the composite structure. As a result of the electrochemical, spectroelectrochemical investigation and surface morphology analyses of the obtained conductive polymer, it has been found that anionic CMC makes improvements in the electrical, optical and mechanical properties of the polymer by making the plasticizing effect and acting as a dopant. Furthermore, in the presence of nanocarbon materials on electrode surface, it has been determined that the polymerization potential reduced and more stable and long-lasting polymeric films which are crucial for technological applications have been obtained.
关键词： Electrochemical polymerization,Composite materials,Conducting polymers,Carboxymethyl cellulose
更新于2025-09-23 15:23:52
-
Ultra-broadband metamaterial absorber with graphene composites fabricated by 3D printing
摘要： An ultra-broadband electromagnetic (EM) absorber composed of composite metamaterials was designed, fabricated and characterized. Polylactic-acid/reduced graphene oxide (PLA/RGO) composites with different amounts of RGO were prepared as a primary material collection. To provide good impedance matching and efficient wave attenuation, the multilayer absorbers were designed with a gradient index (GRIN) of characteristic impedance by manipulating the RGO content and the geometric parameters of the unit cell. The absorbers with different numbers of layers were fabricated by a material extrusion process, and then the reflection loss (RL) of the prepared samples was measured. Results showed that the methodology for designing a metamaterial absorber with gradient impedance and fabricating through a 3D printing process was effective in producing ultra-broadband absorbers. The seven-layer absorber achieved an absorption above 90% in a broad bandwidth of 4.5–40 GHz. This work could provide inspiration for upgrading the performance of some conventional absorbing composites through a rational design of the composite proportion and structure.
关键词： Microwave absorption,Multilayer structure,3D printing,Composite materials,Metamaterials
更新于2025-09-23 15:23:52
-
Enhancing the photocatalytic activity of ZnO by using tourmaline
摘要： The ZnO/tourmaline composite was synthesized by a facile precipitation-hydrothermal method. The composite showed significantly enhanced photocatalytic activity towards degradation of methylene blue (MB) compared with pure ZnO. The degradation rate maintained 90.8% after five successive photocatalytic reaction cycles in the presence of the composite. The results indicated that the enhanced photocatalytic performance of the composite was ascribed to the exposed active sites originated from the improved specific surface area, good interaction between ZnO and tourmaline, and furthermore, tourmaline’s ability of leading the photo-induced e- transferred directionally to achieve separation of e-/h+ pairs. As an earth-abundant polar mineral, tourmaline had potential application in the photocatalytic field.
关键词： Semiconductors,Photocatalysts,Composite materials,Tourmaline,ZnO
更新于2025-09-23 15:23:52
-
Developing New Materials for Electron Beam Melting: Experiences and Challenges
摘要： Lack of industrially available materials for additive manufacturing (AM) of metallic materials along with the promises of materials with improved or unique properties provides a strong drive for developing new process/material combinations. As powder bed technologies for metallic materials are relatively new to the market, and to some extent are only maturing, developers of new process/material combinations have certain challenges to overcome. Firstly, basic knowledge on the behavior of materials (even those well established for other applications) under extreme conditions of melting/solidification with beam-based AM methods is far from being adequate. Secondly, manufacturing of the equipment is up to date driven by industrial application, thus optimization of the AM machines for small test batches of powders is still belongs to research and development projects. Also, majority of the powder manufacturers are primarily driven by the market development, and even they are well aware of the demands imposed by the powder bed AM machines, availability of small test batches of adequate powders may be problematic or at least quite costly for the R&D oriented users. Present paper describes the experiences in developing new materials for EBM A2 machine by Arcam EBM, modified for operating with powder batches of 100-200 ml and less. In particular it discusses achievements and challenges of working with powders from different materials with specifications far beyond the range suggested by machine manufacturer. Also it discusses the possibility of using blended rather than pre-alloyed powders for achieving both composite-like and alloyed materials in the same part by steering electron beam energy deposition strategy.
关键词： Electron Beam Melting,material development,composite materials,Additive Manufacturing,blended powders,in situ alloying
更新于2025-09-23 15:23:52
-
Fabrication and enhanced photocatalytic property of TiO2-ZnO composite photocatalysts
摘要： TiO2 nanotube and TiO2-ZnO composite photocatalysts were fabricated by simple hydrothermal method, and the photocatalytic property of as-prepared samples were analyzed by the photo degradation of rhodamine B water solutions under visible light irradiation. The prepared TiO2-ZnO composite photocatalysts exhibited excellent property in photo degradation of rhodamine B water solution, which is better than that of P25. The enhancement photocatalytic property of target photocatalysts could be attributed to the reduced band gap energy, the enhanced-surface physic-chemical properties, the separation of photo induced electron-hole pairs and the decreased recombination rate. In addition, TiO2-ZnO composite photocatalysts showed good stability for rhodamine B photo degradation under visible light.
关键词： Microstructure,TiO2-ZnO,Photocatalytic property,Hydrothermal method,Composite materials
更新于2025-09-23 15:23:52
-
SiO2@Graphene Composite Materials Obtained through Different Methods Used as Substrate Materials
摘要： In this work, two different methods were applied to prepare SiO2-Graphene composite materials (SiO2-G). One way to synthesize composite materials was stirred carboxyl functionalized graphene and tetraethyl ortho silicate (TEOS) together at low temperature. In other way, SiO2-G were obtained via an one-pot hydrothermal reaction. We employed SEM to characterize the direct structure and morphology information of materials, subsequently. It could be clearly observed that their morphology were greatly affected by the different preparation methods and resulted in a tremendous change occurred. It is no question that the as-prepared materials with different structure can be used as different substrate materials.
关键词： SiO2,Graphene,Composite,Materials
更新于2025-09-23 15:23:52
-
Preparation of MoS <sub/>2</sub> @ZnO heterostructure with enhanced photocatalytic activity
摘要： In order to effectively solve environmental problems induced by organic pollutants, the MoS2@ZnO heterostructure is successfully fabricated via a two-step hydrothermal method, in which the MoS2 nanosheets grew on the surface of ZnO nanorods. The synthetic heterostructure is demonstrated to possess excellent photocatalytic activity in the degradation of methylene blue (MB) under ultraviolet (UV) and visible light irradiation. The corresponding photodegradation rate constant of MoS2@ZnO heterostructure reaches up to 0.02075 min-1 and 0.00916 min-1, which are higher than that of pure ZnO (0.00514 min-1 and 0.00048 min-1) under the same reaction conditions. Obviously, compared with pure ZnO, the photocatalytic activity of the MoS2@ZnO heterostructure has been significantly improved. This could be attributed to the increased specific surface area of photocatalyst and the formation of heterostructure between ZnO and MoS2 after loading the MoS2 on the surface of ZnO nanorods. Which help to provide more reaction sites for the adsorption of pollutant and improve the separation efficiency of photogenerated electron-hole pairs.
关键词： MoS2,composite materials,ZnO,photocatalytic activity,heterostructure
更新于2025-09-23 15:22:29
-
The Comparison of the Photocatalytic Performance Shown by TiO <sub/>2</sub> and TiO <sub/>2</sub> /WO <sub/>3</sub> Composites— A Parametric and Kinetic Study
摘要： Kinetic and mechanistic related approaches for mostly titania were intensively studied in the literature. However, combined modelling and kinetic studies are few. Therefore, the present work focuses on modelling the dependence of the degradation kinetics of two model compounds (salicylic acid—SA and methyl orange—MO) on Evonik Aeroxide P25, hydrothermally prepared hierarchical TiO2 and P25/WO3 nanostars, obtained also by hydrothermal crystallization. The obtained individual semiconductors and the composites were characterized using XRD, DRS, SEM, while the photocatalytic degradation of the model pollutants were carried out varying the catalyst load, the initial pollutant concentration and incident light intensity. It was found that the degradation kinetics were independent from the hierarchical nature of the material, while significant dependencies of the degradation efficiency was found from the previously mentioned investigation parameters. All these parametric interdependences were successfully studied and a kinetic model was proposed for both bare TiO2 and TiO2/WO3 composite systems.
关键词： Degradation,Salicylic Acid,Methyl Orange,Kinetic Modelling,Composite Materials
更新于2025-09-23 15:22:29