Showing papers on "Nanocomposite published in 2019"
TL;DR: In this paper, a review of 2D transition metal transition metal carbides, nitrides, and carbonitrides (MXenes) is presented, highlighting the expeditious advances and achievements in design strategies, physico-chemical properties, and catalytic applications of two-dimensional layered MXenes and their nanocomposites.
513 citations
TL;DR: In this article, a facile synthesized porous graphitic carbon with microtubular structure, high graphitization degree and abundant porosity demonstrates an outstanding advantage of excellent conductivity and facilitated mass transport.
Abstract: The preparation processes of efficient photocatalyst containing defect regulation and heterostructure construction are usually complicated and difficult to control at present, besides, the catalyst agglomeration in solution further limits their application. There is an urgent need for designing a potentially cheap, efficient, sustainable and easy-prepared nanocomposite to improve photocatalytic performance. In present study, the facile synthesized porous graphitic carbon with microtubular structure, high graphitization degree and abundant porosity demonstrates an outstanding advantage of excellent conductivity and facilitated mass transport. Such porous graphite biochar (PGBC) self-assembled with g-MoS2 nanosheets is observed by the optimized band gap, enhanced visible light harvesting, accelerated charge transfer and efficient photo-generated carrier’s separation. Considering the favorable specific surface area and pore distribution of PGBC for avoiding nanosheet agglomeration, the as-prepared composites display quite high efficiency for tetracycline hydrochloride (TC) removal based on the synergistic action of the desirable absorption and photocatalytic capability. Mechanism exploration indicates that surface adsorption is mainly dominated by electrostatic interaction, hydrogen bonding, π-π stacking and pore-filling, and hole (h+) and hydroxyl radical (·OH) are the predominant active species responsible for TC degradation. Furthermore, the nanocomposites possess advisable stability performance for TC removal in contaminated river water, further providing an underlying insight for establishing high-efficient and easy-prepared photocatalysts in practical contaminated water remediation.
494 citations
472 citations
TL;DR: In this article, the authors report advanced polymer nanocomposites containing orientated boron nitride nanosheets (BNNSs), which simultaneously exhibit high thermal conductivity enhancement, excellent electrical insulation, and outstanding flexibility.
Abstract: Thermally conductive yet electrically insulating polymer composites are urgently required for thermal management applications of modern electrical systems and electronic devices because of their multifunctionality and ease of processing. However, the thermal conductivity enhancement of polymer composites is usually at the price of the loss of lightweight, the deterioration of flexibility, and electrical insulation. Here we report advanced polymer nanocomposites containing orientated boron nitride nanosheets (BNNSs), which simultaneously exhibit high thermal conductivity enhancement, excellent electrical insulation, and outstanding flexibility. These nanocomposite films can be easily constructed by electrospinning polymer/BNNSs nanocomposite fibers, vertically folding the electrospun nanocomposite fibers and the subsequent pressing. The nanocomposite films exhibit thickness-dependent in-plane thermal conductivity, which can reach 16.3 W/(m·K) in the 18 μm thick nanocomposite film with 33 wt % BNNSs. In add...
446 citations
TL;DR: Highlights • Extraction methods of nanocellulose, surface modification of cellulose fibers, and latest patents trends on cellulose nanocomposites.
399 citations
TL;DR: In this article, the nitrogen-doped Co-C/MWCNTs (multi-walled carbon nanotubes) derived from bimetallic metal-organic frameworks (MOFs) were fabricated by a facile two-step method.
359 citations
TL;DR: In this article, different nanocomposite membrane fabrication and modification techniques for mixed matrix membranes and thin film membranes for both pressure driven and non-pressure driven membranes using different types of nanoparticles, carbon-based materials, and polymers are discussed.
321 citations
TL;DR: The nano-microstructural investigation validates the successful adsorption of Cr(VI) on CS-GO nanocomposite and proves the material is recyclable up to 10 cycles with the minimum loss in adsorbent capacity.
310 citations
TL;DR: In this article, supermolecular aggregates of piperazine (PiP) and phytic acid (PA) have been self-assembled onto the graphene oxide (GO) surface in water to fabricate functionalized GO (PPGO).
Abstract: The development of a green and facile strategy for fabricating ecofriendly, highly effective flame retardants has remain a major challenge. Herein, supermolecular aggregates of piperazine (PiP) and phytic acid (PA) have been self-assembled onto the graphene oxide (GO) surface in water to fabricate functionalized GO (PPGO). The chemical structure and morphology of PPGO are determined by the X-ray photoelectron spectroscopy, transmission electron microscopy and scanning electron microscopy along with the energy dispersive spectroscopy. Due to the introduction of organic component onto the surface of graphene oxide, the adhesion between PPGO and the epoxy resin (EP) matrix is enhanced. As a result, the storage modulus (E′) of EP composites is increased in addition to a better dispersion of PPGO. Compared with the pure EP, the flame resistance of EP/PPGO is significantly improved, exhibiting a 42% decrease in peak heat release rate (pHRR), 22% reduction in total heat release (THR). The reduced flammability of EP is attributed to the synergistic effects afforded by the gas dilution effect of piperazine, char-forming promotion effect of phytic acid and the creation of "tortuous path" barrier effect of GO during burning. This work offers a green and facile approach for creating highly effective graphene-based flame retardants.
293 citations
TL;DR: In this article, a feasible and low-cost method has been developed to synthesize an effective carbon-based microwave absorber, which achieved the maximum reflection loss value of −49.6 dB at 9.2 GHz with 30% loading in the paraffin matrix.
293 citations
TL;DR: Fully functional applications of the ANF/AgNW nanocomposite paper-based electrical heaters are demonstrated, indicating their excellent potential for emerging electronic applications such as wearable devices, artificial intelligence, and high-performance heating systems.
Abstract: High-performance and rapid response electrical heaters with ultraflexibility, superior heat resistance, and mechanical properties are highly desirable for the development of wearable devices, artificial intelligence, and high-performance heating systems in areas such as aerospace and the military. Herein, a facile and efficient two-step vacuum-assisted filtration followed by hot-pressing approach is presented to fabricate versatile electrical heaters based on the high-performance aramid nanofibers (ANFs) and highly conductive Ag nanowires (AgNWs). The resultant ANF/AgNW nanocomposite papers present ultraflexibility, extremely low sheet resistance (minimum Rs of 0.12 Ω/sq), and outstanding heat resistance (thermal degradation temperature above 500 °C) and mechanical properties (tensile strength of 285.7 MPa, tensile modulus of 6.51 GPa with a AgNW area fraction of 0.4 g/m2), benefiting from the partial embedding of AgNWs into the ANF substrate and the extensive hydrogen-bonding interactions. Moreover, the ANF/AgNW nanocomposite paper-based electrical heaters exhibit satisfyingly high heating temperatures (up to ∼200 °C) with rapid response time (10-30 s) at low AgNW area fractions and supplied voltages (0.5-5 V) and possess sufficient heating reliability, stability, and repeatability during the long-term and repeated heating and cooling cycles. Fully functional applications of the ANF/AgNW nanocomposite paper-based electrical heaters are demonstrated, indicating their excellent potential for emerging electronic applications such as wearable devices, artificial intelligence, and high-performance heating systems.
TL;DR: In this paper, DyMn2O5/Ba3Mn 2O8 nanocomposites were prepared by hydrothermal route as potential hydrogen storage materials, for the first time.
TL;DR: In this article, a simple method for the synthesis of a magnetic conducting polymer modified with mercaptoacetic acid (MAA) and silver nanoparticles (Ag NPs) as a promising catalyst for the reduction of organic pollutants is described.
Abstract: Developing innovative technologies for the efficient treatment of wastewater containing toxic organic pollutants is of particular importance worldwide. Removal of organic contaminants from aqueous media through chemical reduction using noble metal-based nanocatalysts, and in the presence of NaBH4, as a reducing agent, has become an established approach in the last few years. Herein, we describe a simple method for the synthesis of a magnetic conducting polymer modified with mercaptoacetic acid (MAA) and silver nanoparticles (Ag NPs) as a promising catalyst for the reduction of organic pollutants. Ag NPs were deposited on the magnetic conducting polymer by the reduction of a silver salt precursor (AgNO3) without the need for a reducing agent or stabilizer. The developed Fe3O4@PPy-MAA/Ag nanocomposite was characterised using FE-SEM, TEM, XRD, XPS, BET and ATR-FTIR. The catalytic performance of the nanocatalyst during the reduction of 4-nitrophenol (4-NP) and organic dyes, namely, methylene blue (MB) and methyl orange (MO) was assessed in aqueous medium at 25 °C. The catalyst exhibited excellent catalytic activity for the reduction of all three targeted organic pollutants (4-NP, MO and MB). The pseudo-first-order rate constants were estimated as 0.5–14.3 × 10−2 min-1, 0.52–24.2 × 10−2 s−1 and 10.1–46.8 × 10−3 s−1 for the reduction of 4-NP, MO and MB, respectively. The magnetic catalyst was separated easily from the reaction medium and recycled without significant loss of catalytic activity up to eight successive cycles. In addition to its green synthesis and reusability, findings from this study show that Fe3O4@PPy-MAA/Ag nanocomposite has the potential efficiency and stability to make it an ideal catalyst in environmental applications via chemical reduction of toxic contaminants from wastewater.
TL;DR: Thermal conductivities calculated by the established improved thermal conduction model were relatively closer to the experimental results than the results obtained from other classical models.
Abstract: Graphene presents an extremely ultra-high thermal conductivity, well above other known thermally conductive fillers. However, graphene tends to aggregate easily due to its strong intermolecular π–π...
TL;DR: In this paper, a graphdiyne (GD)/graphitic carbon nitride (g-C3N4) nanocomposite was successfully synthesized via a facile calcination approach, and display excellent H2-generation performance under visible light.
Abstract: Hydrogen is considered an ideal alternative energy source to replace fossil energy. Herein, a novel graphdiyne (GD)/graphitic carbon nitride (g-C3N4) nanocomposite was successfully synthesized via a facile calcination approach, and display excellent H2-generation performance under visible light. When the mass ratio of GD reaches 0.5 wt% in GD/g-C3N4 nanocomposite, it shows a maximum hydrogen evolution rate, exceeding that of g-C3N4 by 6.7-fold. After systematic characterization, a new C N bond is confirmed to form between GD and g-C3N4 following heat treatment, and this bond serves as a charge carrier channel that facilitates the migration of photogenerated electrons from g-C3N4 to GD. Positive effects, such as a prolonged photogenerated charge carrier lifetime, intensified electron density, decreased reaction overpotential and improved charge carrier mobility, also contribute to the enhanced photocatalytic performance of the nanocomposites. The proposed technique provides a promising approach for modifying photocatalysts in future applications.
TL;DR: In this paper, the bentonite clay was employed to synthesize a geopolymer that can remove heavy metals such as Cu(II), Pb, Ni, Cd, and Hg(II) from industrial wastewaters.
TL;DR: A detailed review of the current developments in the use of polymeric nanocomposite membranes for purifying water is presented in this article, where a specific focus has been placed on better understanding how nanomaterials can be used in a number of different ways, such as nanofiltration, micro-filtration, reverse osmosis and membrane distillation.
TL;DR: Insight into preparation strategies and approaches of MGO's utilization for the removal of pollutants for sustainable water purification and some research challenges to accelerate the synthesized MGOs as adsorbents for the treatment of water pollutants such as toxic and radioactive metal ions and organic and agricultural pollutants are provided.
TL;DR: In this article, an oxygen ion-proton-electron-conducting nanocomposite, BaCo0.7(Ce0.8Y0.2)0.3O3-δ (BCCY), derived from a self-assembly process, was used as a high-performance protonic ceramic fuel cell (PCFC) or mixed O2−/H+ dual-ion conducting fuel cell cathode.
TL;DR: The robust electrochemical properties indicate the composites as promising electrodes for electrochemical energy storage devices.
Abstract: Nanocomposites with a well-defined sandwich-like nanostructure were prepared via in situ growing NiCo-layered double hydroxide nanosheets with tunable Ni/Co ratios on reduced graphene oxide (rGO). Electrochemical impedance spectra and N2 adsorption/desorption isotherms confirmed that these sandwich nanostructures effectively promoted charge transport and enlarged the specific surface area. The nanocomposites with Ni : Co = 2 : 1 exhibited a maximum specific capacitance of 2130 F g−1 at 2 A g−1, excellent rate capability (72.7% retention at 15 A g−1), and cycling stability. Asymmetric supercapacitors were assembled with these nanocomposite cathodes and rGO as a negative electrode (anode), and demonstrated an energy density of 34.5 W h kg−1 at a power density of 772 W kg−1, while maintaining a capacity retention of 86.7% after 10 000 cycles at 5 A g−1. The robust electrochemical properties indicate the composites as promising electrodes for electrochemical energy storage devices.
TL;DR: The solution-processable polymer nanocomposites consisting of readily prepared Al2 O3 fillers with systematically varied morphologies including nanoparticles, nanowires, and nanoplates are reported, significantly outperforming the state-of-the-art dielectric polymers and nanocomPOSites that are typically prepared via tedious, low-yield approaches.
Abstract: Next-generation microelectronics and electrical power systems call for high-energy-density dielectric polymeric materials that can operate efficiently under elevated temperatures. However, the currently available polymer dielectrics are limited to relatively low working temperatures. Here, the solution-processable polymer nanocomposites consisting of readily prepared Al2 O3 fillers with systematically varied morphologies including nanoparticles, nanowires, and nanoplates are reported. The field-dependent electrical conduction of the polymer nanocomposites at elevated temperatures is investigated. A strong dependence of the conduction behavior and breakdown strength of the polymer composites on the filler morphology is revealed experimentally and is further rationalized via computations. The polymer composites containing Al2 O3 nanoplates display a record capacitive performance, e.g., a discharged energy density of 3.31 J cm-3 and a charge-discharge efficiency of >90% measured at 450 MV m-1 and 150 °C, significantly outperforming the state-of-the-art dielectric polymers and nanocomposites that are typically prepared via tedious, low-yield approaches.
TL;DR: In this paper, a petal-like NiCo/NiO-CoO metal/metal oxides with a rational composition embedded in 3D ultrathin nanoporous carbon composite was used directly as a nonprecious electrocatalyst for methanol oxidation reaction.
Abstract: Porous carbon template decorated with mixed transition metals/metal oxides with tunable architecture is becoming increasingly important and attractive as a kind of novel electrode materials. In this way, mixed-metallic metal-organic frameworks (MOFs) provide an opportunity for fabrication of homogeneous mixed metals/metal oxides distribution in the porous carbon frame without any carbon precursor additive. Also, structures, dimensions and electrochemical performance of MOFs can be readily manipulated by simply tuning the metals molar ratio. In this study, we demonstrate the design and fabrication of petal-like NiCo/NiO-CoO metal/metal oxides with a rational composition embedded in 3D ultrathin nanoporous carbon composite)NiCo/NiO-CoO/NPCC(. This nanocomposite is synthesized by a two-steps procedure involving preparation of bimetallic MOFs by partially substituting Ni2+ in the Ni-MOF structure with Co2+ (Ni-Co/BDC [BDC = 1,4-Benzene dicarboxylic acid]) and direct carbonization process in the N2 atmosphere at 900 °C. The prepared nanocomposite was used directly as a non-precious electrocatalyst for methanol oxidation reaction. The results indicated that, in comparison to the monometallic metal/metal oxides distributed in nanoporous carbon composite (Ni/NiO/NPCC and Co/CoO/NPCC), the mixed metals/metal oxides NiCo/NiO-CoO/NPCC exhibits excellent electrochemical performance toward the anodic oxidation of methanol. The unique ultrathin porous petal-like structure with free pores and the enlarged specific surface area provides fast ion/electron transfer, leading to faster kinetics, lower over-potential, and higher electro-catalytic reactivity. Besides their intriguing structural features, the excellent conductivity of carbon frame, as well as a rational composition of two constituents and synergistic effects from cobalt, nickel and their oxides provides favorable catalytic activity for the electro-oxidation of methanol. Therefore, it is believed that this novel multi-component composites demonstrates good electrocatalytic activity and suitable stability towards the methanol oxidation.
TL;DR: In this paper, a series of highly active mediator-free direct dual-Z-scheme Bi2S3/BiVO4/MgIn2S4 hybrid photocatalysts were controllably synthesized by a in-situ growth method.
Abstract: The development of visible-light-driven photocatalysts with high photocatalytic performance is a desired research direction of scholars for energy crisis mitigation and environment restoration. In this study, a series of highly active mediator-free direct dual-Z-scheme Bi2S3/BiVO4/MgIn2S4 hybrid photocatalysts were controllably synthesized by a in-situ growth method for the first time. XRD manifested the coexistence of MgIn2S4, BiVO4 and Bi2S3 in the as-prepared nanocomposites. The intimate 2D-2D hetero-junction interfaces between BiVO4 and MgIn2S4 as well as BiVO4 and Bi2S3 in the hybrid photocatalysts were verified by TEM and HRTEM. The photocatalytic performance of as-fabricated catalysts was estimated by the degradation of carbamazepine (CBZ) under visible light illumination. The results demonstrated that the as-constructed Bi2S3/BiVO4/MgIn2S4 composites displayed significantly improved photocatalytic activity for CBZ degradation by factors of 44.9 and 423.1 compared to MgIn2S4 and BiVO4, respectively. The enhanced photocatalytic performance of Bi2S3/BiVO4/MgIn2S4 composites was actually ascribed to the direct dual-Z-scheme migration mechanism, which was proved by XPS analysis, trapping experiments and ESR results. The formation of direct dual-Z-scheme efficiently enhanced the separation of charge carriers. Furthermore, according to DRS, the expanded light absorption in visible wavelength region also contributed to the boosted photocatalytic activity of Bi2S3/BiVO4/MgIn2S4 composites. The photocatalytic degradation products of CBZ were detected and a tentative degradation pathway was proposed.
TL;DR: A porous silicon-based nanocomposite anode derived from phenylene-bridged mesoporous organosilicas (PBMOs) is reported through a facile sol-gel method and subsequent pyrolysis, which divides the silicon oxide matrix into numerous sub-nanodomains with outstanding structural integrity and cycling stability.
Abstract: The application of high-performance silicon-based anodes, which are among the most prominent anode materials, is hampered by their poor conductivity and large volume expansion. Coupling of silicon-based anodes with carbonaceous materials is a promising approach to address these issues. However, the distribution of carbon in reported hybrids is normally inhomogeneous and above the nanoscale, which leads to decay of coulombic efficiency during deep galvanostatic cycling. Herein, we report a porous silicon-based nanocomposite anode derived from phenylene-bridged mesoporous organosilicas (PBMOs) through a facile sol-gel method and subsequent pyrolysis. PBMOs show molecularly organic-inorganic hybrid character, and the resulting hybrid anode can inherit this unique structure, with carbon distributed homogeneously in the Si-O-Si framework at the atomic scale. This uniformly dispersed carbon network divides the silicon oxide matrix into numerous sub-nanodomains with outstanding structural integrity and cycling stability.
TL;DR: In this article, the authors reported the methods of oxygen-free fast drying assisted solution casting and melt blending for fabricating advanced ultrathin two-dimensional (2D) titanium carbide (Ti3C2Tx)/polypropylene nanocomposites with significantly enhanced initial degradation temperature (79.1°C increase), tensile strength (35.3%), ductility (674.6% increase), and storage modulus (102.2% increase).
TL;DR: In this article, a nanocomposite composed of a bimetallic CoNi-zeolitic imidazole framework embedded by MoS2 nanosheets (MoS2@CoNi-ZIF), as a bifunctional electrocatalyst for non-Pt methanol oxidation reaction (MOR) and overall water splitting in an alkaline solution was explored.
Abstract: We have explored a nanocomposite composed of a bimetallic CoNi-zeolitic imidazole framework embedded by MoS2 nanosheets (MoS2@CoNi-ZIF), as a bifunctional electrocatalyst for non-Pt methanol oxidation reaction (MOR) and overall water splitting in an alkaline solution The series of MoS2@CoNi-ZIF nanocomposites exhibit different catalytic activities Significantly, the MoS2@CoNi-ZIF nanosheet with a ratio of MoS2:CoNi-ZIF = 3:1 (MoS2@CoNi-ZIF(3-1)) shows the excellent electrocatalytic activity for MOR, affording an oxidation potential at 16 V, also with high catalytic current density and durability Moreover, the MoS2@CoNi-ZIF(3-1) nanocomposite shows a superior electrocatalytic performance toward HER and OER When the MoS2@CoNi-ZIF(3-1) was applied as the bifunctional catalyst for both the anode and cathode, the voltage applied to a two-electrode cell is 155 V to achieve a current density of 10 mA cm−2 for overall water splitting This work provides a promising electrocatalyst for developing high-performance non-Pt-based clean energy and fuel cells in alkaline solution
TL;DR: The ionogel nanocomposite-based strain sensor exhibits good reliability and excellent durability after 500 cycles, as well as a large gauge factor of 20 when it is stretched under a strain of 800-1400%.
Abstract: Fabricating a strain sensor that can detect large deformation over a curved object with a high sensitivity is crucial in wearable electronics, human/machine interfaces, and soft robotics. Herein, an ionogel nanocomposite is presented for this purpose. Tuning the composition of the ionogel nanocomposites allows the attainment of the best features, such as excellent self-healing (>95% healing efficiency), strong adhesion (347.3 N m-1 ), high stretchability (2000%), and more than ten times change in resistance under stretching. Furthermore, the ionogel nanocomposite-based sensor exhibits good reliability and excellent durability after 500 cycles, as well as a large gauge factor of 20 when it is stretched under a strain of 800-1400%. Moreover, the nanocomposite can self-heal under arduous conditions, such as a temperature as low as -20 °C and a temperature as high as 60 °C. All these merits are achieved mainly due to the integration of dynamic metal coordination bonds inside a loosely cross-linked network of ionogel nanocomposite doped with Fe3 O4 nanoparticles.