Showing papers on "Nanocomposite published in 2015"
TL;DR: The design and fabrication of a metal-free carbon nanodot–carbon nitride (C3N4) nanocomposite is reported and its impressive performance for photocatalytic solar water splitting is demonstrated.
Abstract: The use of solar energy to produce molecular hydrogen and oxygen (H2 and O2) from overall water splitting is a promising means of renewable energy storage. In the past 40 years, various inorganic and organic systems have been developed as photocatalysts for water splitting driven by visible light. These photocatalysts, however, still suffer from low quantum efficiency and/or poor stability. We report the design and fabrication of a metal-free carbon nanodot-carbon nitride (C3N4) nanocomposite and demonstrate its impressive performance for photocatalytic solar water splitting. We measured quantum efficiencies of 16% for wavelength λ = 420 ± 20 nanometers, 6.29% for λ = 580 ± 15 nanometers, and 4.42% for λ = 600 ± 10 nanometers, and determined an overall solar energy conversion efficiency of 2.0%. The catalyst comprises low-cost, Earth-abundant, environmentally friendly materials and shows excellent stability.
3,553 citations
TL;DR: Recently, carbonaceous nanofillers such as graphene and carbon nanotubes (CNTs) play a promising role due to their better structural, functional properties and broad range of applications in every field as mentioned in this paper.
1,097 citations
TL;DR: In this article, the authors summarized the recent scientific and technological advances in the development of nanocomposite membranes for water treatment and discussed challenges and future research directions in developing high performance nanocomposition membranes.
822 citations
TL;DR: Recent and in-progress state-of-the-art advancements in the application of core-shell nanoarchitecture strategies to design and prepare high-k polymer nanocomposites are summarized.
Abstract: High-k polymer nanocomposites have considerable potential in energy storage and dielectric applications because of their ease of processing, flexibility, and low cost. Core-shell nanoarchitecture strategies are versatile and powerful tools for the design and synthesis of advanced high-k polymer nanocomposites. Recent and in-progress state-of-the-art advancements in the application of core-shell nanoarchitecture strategies to design and prepare high-k polymer nanocomposites are summarized. Special focus is directed to emphasizing their advantages over conventional melt-mixing and solution-mixing methods: first, homogeneous nanoparticle dispersion can be easily achieved even in highly loaded nanocomposites; second, the dielectric constant of the nanocomposites can be effectively enhanced and meanwhile the high breakdown strength can be well-preserved; third, for nanocomposites filled with electrically conductive nanoparticles, dielectric loss can be effectively surpressed, and meanwhile a high dielectric constant can be achieved. In addition, fundamental insights into the roles of the interfaces on the dielectric properties of the nanocomposites can be probed. The last part of the article is concluded with current problems and future perspectives of utilizing the core-shell nanoarchitecture strategies for the development of high-k polymer nanocomposites.
683 citations
TL;DR: In this paper, the authors focus on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene.
Abstract: Rapid innovation in nanotechnology in recent years enabled development of advanced metal matrix nanocomposites for structural engineering and functional devices. Carbonous materials, such as graphite, carbon nanotubes (CNT's), and graphene possess unique electrical, mechanical, and thermal properties. Owe to their lubricious nature, these carbonous materials have attracted researchers to synthesize lightweight self-lubricating metal matrix nanocomposites with superior mechanical and tribological properties for several applications in automotive and aerospace industries. This review focuses on the recent development in mechanical and tribological behavior of self-lubricating metallic nanocomposites reinforced by carbonous nanomaterials such as CNT and graphene. The review includes development of self-lubricating nanocomposites, related issues in their processing, their characterization, and investigation of their tribological behavior. The results reveal that adding CNT and graphene to metals decreases both coefficient of friction and wear rate as well as increases the tensile strength. The mechanisms involved for the improved mechanical and tribological behavior is discussed.
673 citations
TL;DR: Among the three Co/C composites obtained at different temperatures, co/C-500 obtained at 500 °C exhibited the best performance for electromagnetic wave absorption, ascribed to the synergetic effects between the highly porous structure and multiple components, which significantly improved impedance matching.
Abstract: Composites incorporating ferromagnetic metal nanopartices into a highly porous carbon matrix are promising as electromagnetic wave absorption materials. Such special composite nanomaterials are potentially prepared by the thermal decomposition of metal–organic framework (MOF) materials under controlled atmospheres. In this study, using Co-based MOFs (Co-MOF, ZIF-67) as an example, the feasibility of this synthetic strategy was demonstrated by the successful fabrication of porous Co/C composite nanomaterials. The atmosphere and temperature for the thermal decomposition of MOF precursors were crucial factors for the formation of the ferromagnetic metal nanopartices and carbon matrix in the porous Co/C composites. Among the three Co/C composites obtained at different temperatures, Co/C-500 obtained at 500 °C exhibited the best performance for electromagnetic wave absorption. In particular, the maximum reflection loss (RL) of Co/C-500 reached −35.3 dB, and the effective absorption bandwidth (RL ≤ −10 dB) was ...
666 citations
TL;DR: It is found that the carbon nanotube-silicone rubber based strain sensors possess super-stretchability and high reliability for strains as large as 500%.
Abstract: Super-stretchable, skin-mountable, and ultra-soft strain sensors are presented by using carbon nanotube percolation network–silicone rubber nanocomposite thin films. The applicability of the strain sensors as epidermal electronic systems, in which mechanical compliance like human skin and high stretchability (e>100%) are required, has been explored. The sensitivity of the strain sensors can be tuned by the number density of the carbon nanotube percolation network. The strain sensors show excellent hysteresis performance at different strain levels and rates with high linearity and small drift. We found that the carbon nanotube–silicone rubber based strain sensors possess super-stretchability and high reliability for strains as large as 500%. The nanocomposite thin films exhibit high robustness and excellent resistance–strain dependency for over ∼1380% mechanical strain. Finally, we performed skin motion detection by mounting the strain sensors on different parts of the body. The maximum induced strain by the bending of the finger, wrist, and elbow was measured to be ∼ 42%, 45% and 63%, respectively. S Online supplementary data available from stacks.iop.org/NANO/26/375501/mmedia
588 citations
TL;DR: Results showed that the Ag nanoparticles induced visible light activity and facilitated efficient charge separation in the ZnO/Ag/CdO nanocomposite, thereby improving the photocatalytic performance.
574 citations
TL;DR: In this article, a cubic framework of amorphous carbon and uniformly dispersed core-shell Fe@graphitic carbon nanoparticles is used to construct a high-performance microwave absorber.
Abstract: Composites of magnetic metal nanoparticles and carbon materials are highly desirable for high-performance microwave absorbers due to their compatible dielectric loss and magnetic loss abilities. In this article, novel nanocomposites, Fe/C nanocubes, have been successfully prepared through an in situ route from a metal–organic framework, Prussian blue, by controlled high-temperature pyrolysis. The resultant nanocubes are actually composed of a cubic framework of amorphous carbon and uniformly dispersed core–shell Fe@graphitic carbon nanoparticles. Within the studied pyrolysis temperature range (600–700 °C), the porous structure, iron content, magnetic properties, and graphitization degree of the Fe/C nanocubes can be well modulated. Particularly, the improved carbon graphitization degree, both in amorphous frameworks and graphitic shells, results in enhanced complex permittivity and dielectric loss properties. The homogeneous chemical composition and microstructure stimulate the formation of multiple dielectric resonances by regularizing various polarizations. The synergistic effect of dielectric loss, magnetic loss, matched impedance, and dielectric resonances accounts for the improved microwave absorption properties of the Fe/C nanocubes. The absorption bands of the optimum one obtained at 650 °C are superior to most composites ever reported. By considering the good chemical homogeneity and microwave absorption, we believe that the as-fabricated Fe/C nanocubes will be promising candidates as highly effective microwave absorbers.
545 citations
TL;DR: Sandwich-structured BaTiO3 /poly(vinylidene fluoride) (PVDF) nanocomposites are successfully prepared by the solution-casting method layer by layer and possess both high breakdown strength and large dielectric polarization simultaneously.
Abstract: Sandwich-structured BaTiO3 /poly(vinylidene fluoride) (PVDF) nanocomposites are successfully prepared by the solution-casting method layer by layer. They possess both high breakdown strength and large dielectric polarization simultaneously. An ultra-high energy-storage density of 18.8 J cm(-3) can be achieved by adjusting the volume fraction of ceramic fillers: this is almost three times larger than that of pure PVDF.
496 citations
TL;DR: Improved mechanical properties of nanocomposites is due to the uniform dispersion of functionalised graphene and strong interfacial bonding between modified graphene and epoxy resin as confirmed by microscopy observations.
Abstract: Thermally reduced graphene nanoplatelets were covalently functionalised via Bingel reaction to improve their dispersion and interfacial bonding with an epoxy resin. Functionalised graphene were characterized by microscopic, thermal and spectroscopic techniques. Thermal analysis of functionalised graphene revealed a significantly higher thermal stability compared to graphene oxide. Inclusion of only 0.1 wt% of functionalised graphene in an epoxy resin showed 22% increase in flexural strength and 18% improvement in storage modulus. The improved mechanical properties of nanocomposites is due to the uniform dispersion of functionalised graphene and strong interfacial bonding between modified graphene and epoxy resin as confirmed by microscopy observations.
TL;DR: A facile and scalable strategy to fabricate hierarchical porous MWCNTs/Co3O4 nanocomposites has been reported, with the help of a morphology-maintained annealing treatment of carbon nanotubes inserted metal organic frameworks (MOFs).
Abstract: Hybridizing nanostructured metal oxides with multiwalled carbon nanotubes (MWCNTs) is highly desirable for the improvement of electrochemical performance of lithium-ion batteries. Here, a facile and scalable strategy to fabricate hierarchical porous MWCNTs/Co3O4 nanocomposites has been reported, with the help of a morphology-maintained annealing treatment of carbon nanotubes inserted metal organic frameworks (MOFs). The designed MWCNTs/Co3O4 integrates the high theoretical capacity of Co3O4 and excellent conductivity as well as strong mechanical/chemical stability of MWCNTs. When tested as anode materials for lithium-ion batteries, the nanocomposite displays a high reversible capacity of 813 mAh g–1 at a current density of 100 mA g–1 after 100 charge–discharge cycles. Even at 1000 mA g–1, a stable capacity as high as 514 mAh g–1 could be maintained. The improved reversible capacity, excellent cycling stability, and good rate capability of MWCNTs/Co3O4 can be attributed to the hierarchical porous structure...
TL;DR: GO-Ag nanocomposite, as a kind of antibacterial material, had a great promise for application in a wide range of biomedical applications and was demonstrated to have good cytocompatibility and antibacterial properties.
Abstract: In this work, we report a facile and green approach to prepare a uniform silver nanoparticles (AgNPs) decorated graphene oxide (GO) nanocomposite (GO-Ag). The nanocomposite was fully characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectra, ultraviolet–visible (UV–vis) absorption spectra, and X-ray photoelectron spectroscopy (XPS), which demonstrated that AgNPs with a diameter of approximately 22 nm were uniformly and compactly deposited on GO. To investigate the silver ion release behaviors, HEPES buffers with different pH (5.5, 7, and 8.5) were selected and the mechanism of release actions was discussed in detail. The cytotoxicity of GO-Ag nanocomposite was also studied using HEK 293 cells. GO-Ag nanocomposite displayed good cytocompatibility. Furthermore, the antibacterial properties of GO-Ag nanocomposite were studied using Gram-negative E. coli ATCC 25922 and Gram-positive S. aureus ATCC 6538 by both the plate count method and disk diffusion method. The nanoc...
TL;DR: The one-step and facile synthesis of multi-enzyme-containing metal-organic framework (MOF) nanocrystals in aqueous solution at 25 °C was reported in this study.
TL;DR: A soft, thin, and stretchable heater is developed by using a nanocomposite of silver nanowires and a thermoplastic elastomer to create a novel wearable system for long-term, continuous articular thermotherapy.
Abstract: Thermal therapy is one of the most popular physiotherapies and it is particularly useful for treating joint injuries. Conventional devices adapted for thermal therapy including heat packs and wraps have often caused discomfort to their wearers because of their rigidity and heavy weight. In our study, we developed a soft, thin, and stretchable heater by using a nanocomposite of silver nanowires and a thermoplastic elastomer. A ligand exchange reaction enabled the formation of a highly conductive and homogeneous nanocomposite. By patterning the nanocomposite with serpentine-mesh structures, conformal lamination of devices on curvilinear joints and effective heat transfer even during motion were achieved. The combination of homogeneous conductive elastomer, stretchable design, and a custom-designed electronic band created a novel wearable system for long-term, continuous articular thermotherapy.
TL;DR: In this paper, a facile and inexpensive route has been developed to synthesize a ternary ZnO/Ag/Mn2O3 nanocomposite having nanorod structures based on the thermal decomposition method.
Abstract: A facile and inexpensive route has been developed to synthesize a ternary ZnO/Ag/Mn2O3 nanocomposite having nanorod structures based on the thermal decomposition method. The as-synthesized ternary ZnO/Ag/Mn2O3 nanocomposite was characterized and used for visible light-induced photocatalytic, sensing and antimicrobial studies. The ternary ZnO/Ag/Mn2O3 nanocomposite exhibited excellent and enhanced visible light-induced photocatalytic degradation of industrial textile effluent (real sample analysis) compared to pure ZnO. Sensing studies showed that the ternary ZnO/Ag/Mn2O3 nanocomposite exhibited outstanding and improved detection of uric acid (UA) and ascorbic acid (AA). It also showed effective and efficient bactericidal activities against Staphylococcus aureus and Escherichia coli. These results suggest that the small size, high surface area and synergistic effect among ZnO, AgNPs and Mn2O3 induced visible light photocatalytic activity by decreasing the recombination of photogenerated electrons and holes, and extending the response of pure ZnO to visible light, enhanced sensing of UA and AA and antimicrobial activity. Overall, the ternary ZnO/Ag/Mn2O3 nanocomposite is a valuable material that can be used for a range of applications, such as visible light-induced photocatalysis, sensing and antimicrobial activity. Therefore, ternary nanocomposites could have important applications in environmental science, sensing, and biological fields.
TL;DR: A new method for evaluating the elastic properties of the interfacial region is developed by examining the fracture behavior of carbon nanotube reinforced poly (methyl methacrylate) matrix composites under tension using molecular dynamics simulations.
Abstract: The remarkable mechanical properties of carbon nanotubes, such as high elastic modulus and tensile strength, make them the most ideal and promising reinforcements in substantially enhancing the mechanical properties of resulting polymer/carbon nanotube composites. It is acknowledged that the mechanical properties of the composites are significantly influenced by interfacial interactions between nanotubes and polymer matrices. The current challenge of the application of nanotubes in the composites is hence to determine the mechanical properties of the interfacial region, which is critical for improving and manufacturing the nanocomposites. In this work, a new method for evaluating the elastic properties of the interfacial region is developed by examining the fracture behavior of carbon nanotube reinforced poly (methyl methacrylate) (PMMA) matrix composites under tension using molecular dynamics simulations. The effects of the aspect ratio of carbon nanotube reinforcements on the elastic properties, i.e. Young's modulus and yield strength, of the interfacial region and the nanotube/polymer composites are investigated. The feasibility of a three-phase micromechanical model in predicting the elastic properties of the nanocomposites is also developed based on the understanding of the interfacial region.
TL;DR: The performance of solution exfoliated MoS2 thin flexible membranes as supercapacitor electrodes in a symmetrical coin cell arrangement using an aqueous electrolyte (Na2SO4) demonstrates a simple and scalable application of layered 2D materials toward electrochemical energy storage.
Abstract: Two-dimensional materials, such as graphene and molybdenum disulfide (MoS2), can greatly increase the performance of electrochemical energy storage devices because of the combination of high surface area and electrical conductivity. Here, we have investigated the performance of solution exfoliated MoS2 thin flexible membranes as supercapacitor electrodes in a symmetrical coin cell arrangement using an aqueous electrolyte (Na2SO4). By adding highly conductive graphene to form nanocomposite membranes, it was possible to increase the specific capacitance by reducing the resistivity of the electrode and altering the morphology of the membrane. With continued charge/discharge cycles the performance of the membranes was found to increase significantly (up to 800%), because of partial re-exfoliation of the layered material with continued ion intercalation, as well as increasing the specific capacitance through intercalation pseudocapacitance. These results demonstrate a simple and scalable application of layered...
TL;DR: In this article, a novel thin film nanocomposite reverse osmosis (TFN-RO) membrane was prepared by interfacial polymerization of m-phenylenediamine (MPD) and trimesoyl chloride (TMC) monomers and embedding reduced graphene oxide (rGO)/TiO 2 nanocompositionite in its polyamide layer.
TL;DR: In this paper, a review article summarizes the recent progress made in the area of organic thermoelectrics (TEs), including organic molecular structures, devices, characterization methods, and approaches to improve the performance.
Abstract: Organic semiconductor materials have advantages of low cost, light weight, mechanical flexibility and low-temperature solution processability over large areas, enabling the development of personal, portable, and flexible thermal modules. This review article summarizes the recent progress made in the area of organic thermoelectrics (TEs), including organic molecular structures, devices, characterization methods, and approaches to improve the performance. We begin with the discussion of each TE parameter and particularly their correlations in organic TEs. Then the TE applications of molecular organic semiconductors, poly(3,4-ethylenedioxythiophene), polymer nanostructures and molecular junctions are reviewed. Next we turn to highlight the nanocomposites of polymers and carbon nanotubes or nanocrystals, which lead to enhanced TEs. Interestingly, the merging of TEs and photovoltaics offers a new direction towards a great capability of electric energy output. Critical challenges of organic TE materials include stability, sample preparation and measurement techniques, which are also discussed. Finally, the relationships among organic semiconductor structures, hybrid composites, doping states, film morphology and TE performance are revealed, and a viable avenue is envisioned for synergistic optimization of organic TEs.
TL;DR: Graphdiyne (GDY), a novel kind of two-dimensional carbon allotrope consisting of sp- and sp(2)-hybridized carbon atoms, is found to be able to serve as the reducing agent and stabilizer for electroless deposition of highly dispersed Pd nanoparticles owing to its low reduction potential and highly conjugated electronic structure.
Abstract: Graphdiyne (GDY), a novel kind of two-dimensional carbon allotrope consisting of sp- and sp2-hybridized carbon atoms, is found to be able to serve as the reducing agent and stabilizer for electroless deposition of highly dispersed Pd nanoparticles owing to its low reduction potential and highly conjugated electronic structure. Furthermore, we observe that graphdiyne oxide (GDYO), the oxidation form of GDY, can be used as an even excellent substrate for electroless deposition of ultrafine Pd clusters to form Pd/GDYO nanocomposite that exhibits a high catalytic performance toward the reduction of 4-nitrophenol. The high catalytic performance is considered to benefit from the rational design and electroless deposition of active metal catalysts with GDYO as the support.
TL;DR: Gelatin-based zinc oxide nanoparticle (ZnO NPs) nanocomposite films were characterized by UV-visible spectroscopy, FE-SEM, FT-IR, thermogravimetric analysis, and XRD as mentioned in this paper.
TL;DR: In this paper, the authors investigated the tensile performance and fracture behavior of aluminum matrix composites reinforced with TiB2 nano and microparticles, and found that the porosity of the composites increased with increasing volume fraction and decreasing particle size.
TL;DR: In this paper, a template-free method for preparing 3D porous γ-Fe2O3@C nanocomposite using an aerosol spray pyrolysis technology is reported.
Abstract: A simple and template-free method for preparing three-dimensional (3D) porous γ-Fe2O3@C nanocomposite is reported using an aerosol spray pyrolysis technology. The nanocomposite contains inner-connected nanochannels and γ-Fe2O3 nanoparticles (5 nm) uniformly embedded in a porous carbon matrix. The size of γ-Fe2O3 nanograins and carbon content can be controlled by the concentration of the precursor solution. The unique structure of the 3D porous γ-Fe2O3@C nanocomposite offers a synergistic effect to alleviate stress, accommodate large volume change, prevent nanoparticles aggregation, and facilitate the transfer of electrons and electrolyte during prolonged cycling. Consequently, the nanocomposite shows high-rate capability and long-term cyclability when applied as an anode material for Na-ion batteries (SIBs). Due to the simple one-pot synthesis technique and high electrochemical performance, 3D porous γ-Fe2O3@C nanocomposites have a great potential as anode materials for rechargeable SIBs.
TL;DR: In this paper, a 3D printing system based on liquid deposition modeling (LDM) is developed for the fabrication of conductive 3D nanocomposite-based microstructures with arbitrary shapes.
Abstract: In this work, a new three-dimensional (3D) printing system based on liquid deposition modeling (LDM) is developed for the fabrication of conductive 3D nanocomposite-based microstructures with arbitrary shapes. This technology consists in the additive multilayer deposition of polymeric nanocomposite liquid dispersions based on poly(lactic acid) (PLA) and multi-walled carbon nanotubes (MWCNTs) by means of a home-modified low-cost commercial benchtop 3D printer. Electrical and rheological measurements on the nanocomposite at increasing MWCNT and PLA concentrations are used to find the optimal processing conditions and the printability windows for these systems. In addition, examples of conductive 3D microstructures directly formed upon 3D printing of such PLA/MWCNT-based nanocomposite dispersions are presented. The results of our study open the way to the direct deposition of intrinsically conductive polymer-based 3D microstructures by means of a low-cost LDM 3D printing technique.
TL;DR: In this article, a microcrack mechanism was proposed based on microscopy of the fracture surfaces, which indicated that the coalescence of microcracks may facilitate crack propagation, lowering the fracture toughness.
Abstract: The toughening effects of graphene and graphene-derived materials on thermosetting epoxies are investigated. Graphene materials with various structures and surface functional groups are incorporated into an epoxy resin by in situ polymerization. Graphene oxide (GO) and GO modified with amine-terminated poly(butadiene-acrylonitrile) (ATBN) are chosen to improve the dispersion of graphene nanosheets in epoxy and increase their interfacial adhesion. An impressive toughening effect is observed with less than 0.1 wt% graphene. A maximum in toughness at loadings as small as 0.02 wt% or 0.04 wt% is observed for all four types of graphene studied. An epoxy nanocomposite with ATBN-modified GO shows a 1.5-fold improvement in fracture toughness and a corresponding 2.4-fold improvement in fracture energy at 0.04 wt% of graphene loading. At such low loadings, these graphene-type materials become economically feasible components of nanocomposites. A microcrack mechanism is proposed based on microscopy of the fracture surfaces. Due to the stress concentration by graphene nanosheets, microcracks may be formed to absorb the fracture energy. However, above a certain graphene concentration, the coalescence of microcracks appears to facilitate crack propagation, lowering the fracture toughness. Crack defl ection and pinning likely contribute to the slow increase in fracture toughness at higher loadings.
TL;DR: In this article, the authors present a review of the state-of-the-art in the field of instrumented indentation of polymer nanocomposite materials and present challenges and future perspectives in the application of depth-sensing instrumentation to characterize mechanical properties.
TL;DR: In this paper, the preparation and physicochemical characterization of graphene-based elastomeric nanocomposites are discussed in detail, and various preparation routes for the efficient dispersion of graphene in elastomers are discussed, while aspects such as interfacial bonding between the filler and the matrix or interactions between the fillers have been thoroughly analyzed.
TL;DR: TiO2-Ti3C2 nanocomposite could be a promising matrix for the fabrication of mediator-free biosensors, and might find wide potential applications in environmental analysis and biomedical detection.
TL;DR: In this article, a synergetic effect between the photocatalysis on TiO2 and the thermocatalysis of CeO2 was found to increase their catalytic activity.
Abstract: TiO2/CeO2 nanocomposites of anatase TiO2 nanoparticles supported on microsized mesoporous CeO2 were prepared and characterized by SEM, TEM, BET, XRD, Raman, XPS, and diffuse reflectance UV–vis absorption. The formation of the TiO2/CeO2 nanocomposites considerably enhances their catalytic activity for the gas-phase oxidation of benzene, one of the hazardous volatile organic compounds (VOCs), under the irradiation of a Xe lamp compared to pure CeO2 and TiO2. A solar-light-driven thermocatalysis on CeO2 is found for the TiO2/CeO2 nanocomposites. There is a synergetic effect between the photocatalysis on TiO2 and the thermocatalysis on CeO2 for the TiO2/CeO2 nanocomposites, which significantly increases their catalytic activity. The CO2 formation rate (rCO2) of the TiO2/CeO2 nanocomposite with the Ti/Ce molar ratio of 0.108 under the synergetic photothermocatalytic condition is 36.4 times higher than its rCO2 under the conventional photocatalytic condition at near room temperature. CO temperature-programmed r...