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Photoluminescent porous aerogel monoliths containing ZnEu-complex: the first example of aerogel modified with a heteronuclear metal complex
摘要: A procedure for the chemical immobilization of a new ZnII–EuIII heterobimetallic complex in the SiO2 aerogel matrix has been developed. In this Zn–Eu complex, a peripheral non-luminescent Zn ion acts as a binder to a silica matrix and prevents direct interaction of rare-earth ions with OH? and NH? groups in the silica matrix, which would have a detrimental effect on the luminescence of lanthanides. The procedure includes the synthesis of complexes, co-gelation of the obtained complex with SiO2 sol, the washing of lyogels, and their subsequent supercritical drying in CO2. The composition and properties of the obtained aerogels were investigated using a low-temperature nitrogen adsorption technique, helium pycnometry, FTIR, Raman, UV–visible, and luminescence spectroscopy, XPS, PXRD, SEM, TEM, TGA combined with mass spectrometry, and small-angle neutron scattering. The aerogels modi?ed with the ZnII–EuIII complex demonstrated strong red luminescence upon excitation with UV light.
关键词: Aerogel,Silica,Heteronuclear metal complex,Luminescence,Structure
更新于2025-11-21 11:20:42
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Photocatalytic properties of TiO2@Polymer and TiO2@Carbon aerogel composites prepared by atomic layer deposition
摘要: Monolithic structured TiO2/aerogel composites were prepared from resorcinol-formaldehyde polymer aerogel (RFA) and its carbon aerogel (RFCA) derivative. A resorcinol-formaldehyde hydrogel was synthesized in a sol-gel reaction and transformed into polymer aerogel by supercritical drying. The RFA was converted to carbon aerogel by pyrolysis at 900 °C in dry N2. Amorphous and crystalline TiO2 layers were grown from TiCl4 and H2O precursors by atomic layer deposition (ALD) at 80 °C and 250 °C, respectively, on both RFA and RFCA. The substrates and the composites were studied by N2 adsorption, TG/DTA-MS, Raman, SEM-EDX and TEM techniques. Their photocatalytic activity was compared in the UV catalyzed decomposition reaction of methyl orange dye.
关键词: ALD,photocatalysis,carbon aerogel,TiO2,resorcinol-formaldehyde polymer aerogel
更新于2025-11-20 15:33:11
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3D graphene/AgBr/Ag cascade aerogel for efficient photocatalytic disinfection
摘要: To design semiconductor-based photocatalysts with efficient charge carriers separation and transfer remains an enduring goal of artificial photosynthesis toward target redox reactions. Herein, we report a cascade monolith composite of ternary reduced graphene oxide aerogel/silver bromide/silver (RGA/AgBr/Ag) with efficient charge carriers separation, which exhibits much higher activity than bare AgBr toward photocatalytic bacteria inactivation. Mechanistic studies reveal that the reduced graphene oxide aerogel (RGA) scaffold and Ag nanoparticles serve as electron relay mediators to promote the charge carriers separation and transfer. In addition, the metallic Ag nanoparticles derived from the photoreduction of AgBr during the photocatalytic disinfection can further boost the separation of charge carriers. Control experiments demonstrate that the surface plasmon resonance (SPR)-excited hot electrons of Ag nanoparticles also contributes to enhancing the photoactivity of RGA/AgBr/Ag. As such, the synergy of multiple electron transfer behavior integratively leads to the boosted photocatalytic performance of such RGA/AgBr/Ag aerogel for bacteria inactivation with convenient recyclable operability.
关键词: charge transfer,aerogel,silver bromide,Ag nanoparticles,reduced graphene oxide
更新于2025-09-23 15:23:52
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A Novel Multilayer Sandwich Fabric-based Composite Material for Infrared Stealth and Super Thermal Insulation Protection
摘要: At present, infrared stealth materials for advanced detection and stealth technology is usually prepared with low emissivity coating on the surface, but there are very few efficient infrared stealth materials based on textiles with lightweight and flexible features. In this paper, we designed a carbon nanotube-doped aerogel (CNTAs) sandwich structure on polyimide (PI) fabric by hot pressing and then coated with a low emissivity Al-doped ZnO (ZAO) on the outer surface. The surface emissivity lower than 0.5 due to the existence of ZAO and the thermal conductivity of the intermediate interlayer aerogels as low as 0.013 W/(m?K). Additionally, through experiments, theoretical derivation and simulation analysis, we found the resultant composite demonstrated a high infrared stealth performance with super insulation effect, implying it will have a fine prospect in infrared stealth and thermal insulation protection fields with its unique structure and excellent properties.
关键词: Carbon Nanotube-doped Aerogel,Sandwich Structure,Infrared Stealth,Polyimide Fabric,Thermal Insulation,Al-doped ZnO
更新于2025-09-23 15:23:52
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A novel SiC nanowire aerogel consisted of ultra long SiC nanowires
摘要: SiC nanowire aerogel (SNA) with highly porous 3D nanowire architecture was synthesized by polymer pyrolysis chemical vapor deposition (PPCVD) process to deposit SiC nanowires in the pores of carbon foam, followed by high temperature oxidation of carbon foam. The microstructure of the prepared SNA was characterized by SEM, TEM and a large number of interweaving SiC nanowires with a diameter of 80-100 nm and a length of hundreds of micrometers form the highly porous 3D nanowire architecture of SNA. The prepared SNA possesses the performance combination of ultra-low density (30±7 mg·cm-3), high-temperature oxidation resistance (750 °C), noncombustible and fire resistance property in the fire, excellent thermal insulating property (0.03 W·m-1·k-1 at room temperature in He) and compressive strength of 0.11 MPa, which is applicable as high-temperature heat insulator, ceramic matrix composite, high temperature flue gas filter, fire-proofing material and catalyst carrier.
关键词: Carbon foam,Aerogel,SiC nanowire,CVD
更新于2025-09-23 15:23:52
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One-pot self-assembly of 3D CdS-graphene aerogels with superior adsorption capacity and photocatalytic activity for water purification
摘要: Graphene-based three-dimensional (3D) aerogel hybrids have recently emerged as a new class of functional materials and applied in many fields. In this work, we assemble the spherical CdS nanoparticles in situ in graphene aerogel (GA) by a facile one-pot hydrothermal method. The resultant CdS-GA hybrids possess a hierarchical porous structure and there is strong electronic interaction between CdS and GA, which enhances the adsorption capacity and photocatalytic activity for the elimination of organic contaminants in water under visible light irradiation, such as rhodamine B (RhB), methylene blue (MB), acid chrome blue K (AcbK), methyl orange (MO), and ciprofloxacin (CIP). The removal efficiencies of CdS-GA for MO, MB, CIP, RhB, AcbK are 15.6, 6.6, 4.4, 2.8, and 2.2 times of pure CdS, respectively. Meanwhile, the resultant CdS-GA hybrids display good reusability. In addition, a photocatalytic mechanism is also discussed. This provides a valuable alternative to explore semiconductor-GA hybrids with outstanding adsorption capacity and superior visible-light induced photocatalytic activity.
关键词: Graphene aerogel,Adsorption,Photocatalysis,Hybrids,CdS nanoparticle,organic contaminants
更新于2025-09-23 15:23:52
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Multifunctional ZnO/polyurethane-based solid-solid phase change materials with graphene aerogel
摘要: In this work, multifunctional polyurethane-based phase change materials with zinc oxide (ZnO) and graphene aerogel (GA) were prepared through facile impregnation. ZnO and GA improved the latent heat of the system from 86.8 J/g to 108.1 J/g for the heterogeneous nucleation and chemical mitigations. Furthermore, the photo-/electro-thermal energy conversion efficiency of the system with ZnO and GA is 80.1%, 84.4%, respectively, for the efficient light absorption of ZnO and GA as well as the electrical conductivity of GA. The as-prepared materials with high latent heat, excellent form-stability, remarkable thermal stability as well as reliability, efficient light-/electro-thermal energy conversion, have great prospects for applying in energy harvesting, conversion and storage devices like solar heater, smart textile and greenhouse.
关键词: Graphene aerogel,Light-thermal conversion,Electro-thermal conversion,Zinc oxide
更新于2025-09-23 15:23:52
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Towards Porous Silicon Oxycarbide Materials: Effects of Solvents on Microstructural Features of Poly(methylhydrosiloxane)/Divynilbenzene Aerogels
摘要: We investigate the impact of solvents on the microstructure of poly(methylhydrosiloxane)/divinylbenzene (PMHS/DVB) aerogels. The gels are obtained in highly diluted conditions via hydrosilylation reaction of PMHS bearing Si-H groups and cross-linking it with C=C groups of DVB. Polymer aerogels are obtained after solvent exchange with liquid CO2 and subsequent supercritical drying. Samples are characterized using microscopy and porosimetry. Common pore-formation concepts do not provide a solid rationale for the observed data. We postulate that solubility and swelling of the cross-linked polymer in various solvents are major factors governing pore formation of these PMHS/DVB polymer aerogels.
关键词: preceramic polymers,supercritical drying,aerogel
更新于2025-09-23 15:23:52
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Crystallization kinetics and thermal stability of ZrO <sub/>2</sub> monolithic aerogel improved by SiO <sub/>2</sub> layer
摘要: ZrO2 aerogel modified by SiO2 (ZSA) was synthesized by aging ZrO2 gel in tetraethoxysilane (TEOS) solution using ZrOCl2·8H2O as precursor, and 1,2-propylene oxide (PO) as gelation agent followed by ethanol supercritical fluid drying. Crystallization kinetics and thermal stability of ZSA while calcined at elevated temperature were studied comparing with pure ZrO2 aerogel. The prepared samples were characterized using TG-DSC, N2 adsorption/desorption, SEM and TEM. The results show that thermal stability of ZSA are highly improved due to the SiO2 layer hindering the proliferation, nucleation and growth process of ZrO2.
关键词: ZrO2,thermal stability,aerogel,SiO2,crystallization kinetics
更新于2025-09-23 15:23:52
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Novel Three-Dimensional SiC/Melamine-Derived Carbon Foam-Reinforced SiO <sub/>2</sub> Aerogel Composite with Low Dielectric Loss and High Impedance Matching Ratio
摘要: Novel three-dimensional SiC/melamine-derived carbon foam composite filled by silica aerogel (SiC/MDCF?Aerogel) was first fabricated by the pyrolysis process of commercial melamine foam, chemical vapor deposition of ultrathin SiC films, and the sol?gel method of silica aerogel. The results indicated that the SiC/MDCF?Aerogel composite consisted of the SiC three-dimensional open-celled network structure and the pregnant silica aerogel in the pores. Tiny cracks on the interface of skeletons and clumps were induced during the aging process, which was drastically beneficial to the microwave-absorbing properties. A minimum reflection loss could be obtained as low as ?18.41 dB at the measured frequency of 16.92 GHz when the thickness of the absorber was 3.65 mm, and the reflection loss could drop below ?10 dB when the selected frequencies ranged from 15.80 to 17.52 GHz, along with the thickness ranging from 2.75 to 5.0 mm, which possessed a relatively better microwave absorption performance especially at a higher frequency. Furthermore, the absorption mechanism was also investigated in detail to discuss the influence of the dielectric loss and the impedance matching ratio on the microwave-absorbing performance of SiC/MDCF?Aerogel, which provided certain scientific directions for evaluating the absorbing materials.
关键词: Minimum reflection loss,Tiny cracks,Microwave-absorbing properties,Impedance matching ratio,Dielectric loss,SiC/MDCF?Aerogel
更新于2025-09-23 15:22:29