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Silica aerogel membranes fabricated using removable nitrocellulose scaffolds
摘要： Two different methods were developed to generate silica-based aerogel membranes using nitrocellulose scaffolds. The first method involved incorporating fibers of nitrocellulose (NC) into the sol prior to gelation. NC fibers were either removed using a solvent during aging or calcining after aerogel formation to produce reticulated micron-sized channels in the aerogels. In the second method, an NC lacquer was mixed with the sol, and the mixture separated into a NC-rich phase and a sol-rich phase. The NC phase was subsequently removed from the aerogel using a solvent, creating aerogels with interconnected porosity. Aerogels were prepared from tetraethyloxysilane (TEOS) as a precursor and methyltriethoxysilane (MTES) as a co-precursor. Replacing TEOS with 25 vol% MTES increased the mechanical stability, allowing for greater ease of handling. Additionally, the more open network of the MTES gels led to higher helium gas permeability than that for the pure TEOS gels.
关键词： Silica membrane,Interconnected porosity,Nitrocellulose template,Cellulose nitrate,Silica aerogel
更新于2025-09-23 15:22:29
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In-situ ion exchange synthesis of Ag2S/AgVO3 graphene aerogels for enhancing photocatalytic antifouling efficiency
摘要： Efficient charge separation and cycle stability are critical for water purification by semiconductor photocatalyst. Herein, novel Ag2S/AgVO3 graphene aerogels (Ag2S/AgVO3@GAs) were synthesized via an in-situ ion exchange method. The series of characterization results verified that the Ag2S/AgVO3@GAs synergistically integrate the excellent properties of the Ag2S and AgVO3 into the macroscopic porous graphene aerogel. Furthermore, owing to the chelation of chitosan (CS) for AgVO3 and the ion exchange between well-dispersed AgVO3 and Na2S, the Ag2S can in situ grow on AgVO3, which prevents Ag2S and AgVO3 agglomeration/shedding in the photocatalytic reaction and contributes to the enhanced photocatalytic activity and cyclic stability. Benefiting from the unique structure, the Ag2S/AgVO3@GAs with excellent stability displayed the outstanding photodegradation efficiency for methyl orange (97% removal rate in 40 min) and disinfection activity for Escherichia coli (100% antibacterial efficiency in 36 min).
关键词： Photodegradation,Disinfection,Charge transfer,Three-dimensional graphene aerogel,Heterojunction
更新于2025-09-23 15:22:29
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Integration of 3D Macroscopic Graphene Aerogel with 0D-2D AgVO3-g-C3N4 Heterojunction for Highly Efficient Photocatalytic Oxidation of Nitric Oxide
摘要： The application of three-dimensional (3D) aerogels for immobilizing powder catalysts can greatly enhance the catalyst cycling stability. In this study, we modify two-dimensional (2D) graphitic carbon nitride (g-C3N4) nanosheets with zero-dimensional (0D) silver metavanadate (AgVO3) quantum dots. The resulting 0D-2D heterojunction facilitates the separation of electron-hole pairs, and exhibits high efficiency for removing nitric oxide (NO) at low concentrations (600 ppb) at room temperature. The removal efficiency is much higher than that of pure g-C3N4. The porous network framework of the 3D AgVO3-g-C3N4-graphene hybrid aerogel is formed by bridging of graphene oxide sheets. This results in the heterojunction further enhancing electron-hole separation. The modification of g-C3N4 promotes the separation of photogenerated carriers in a step by step manner, and enhances their oxidation-reduction ability. The AgVO3-g-C3N4-graphene hybrid aerogel exhibits excellent catalytic activity for NO removal (maximum of 65%). Cycling experiments verify the stability and recyclability of the aerogel.
关键词： 0D-2D heterojunction,NO removal,visible light,3D aerogel
更新于2025-09-23 15:21:01
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Application of Co-Mo bimetal/carbon composite in dye-sensitized solar cells and its research on synergy mechanism
摘要： Bimetal/carbon aerogels have many advantages, such as nano-scale properties, low density, large specific surface area, and high porosity, but their application in dye-sensitized solar cells (DSSCs) as a counter electrode (CE) instead of noble metal Pt is relatively rare. In this paper, a low-cost sodium alginate was used to obtain a Co-Mo bimetal/carbon composite through a simple and controlled carbonization process. Using them as CEs of ZnO-based DSSCs, the filling characteristics of dye can be effectively improved. When the Co2+/Mo2+ molar ratio is 1:3, the photoelectric conversion efficiency of Co-Mo bimetal/ carbon composite–based DSSCs is close to the photoelectric conversion efficiency of Pt based, which is considered to be the result of the synergy of the carbon and two metal ions.
关键词： Counter electrode,Bimetal/carbon composite,Synergy,Dye-sensitized solar cells,Aerogel
更新于2025-09-23 15:19:57
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Enhanced photocatalytic activity of a mesoporous TiO2 aerogel decorated onto three-dimensional carbon foam
摘要： TiO2/carbon composites have been well studied as solar-light photocatalysts because they combine the advantages of TiO2 (good photocatalytic activity) and carbon (enhanced charge carrier separation). Mesoporous TiO2 aerogels are fragile by nature and the addition of free-standing three-dimensional (3D) porous carbon foam (CF) not only makes it easy for separation and collection after photocatalytic treatment but also acts as a scaffold for the long-term application of TiO2 aerogels in the photocatalysis. Hence, recent reports have shown that mesoporous TiO2 aerogel/CF composites synthesized by the carbonization of a polymer followed by using the sol-gel method are significant for use in photocatalysis applications. In addition, the 3D macroporous CF not only acts as a support for TiO2 aerogels but also improves the efficiency of light use and extends the photoresponse of TiO2 to the visible region. The TiO2 aerogel was homogeneously distributed onto the 3D CF because of the vacuum infiltration used during the synthesis of the composites. The simulated solar-light irradiated photocatalytic degradation of Rhodamine B organic pollutant was used to evaluate the TiO2 aerogel/CF composite catalysts, which was higher than with a pristine TiO2 aerogel. This facile synthesis approach for 3D foam type TiO2/carbon composites could be useful in the treatment of wastewater.
关键词： anatase,Mesoporous TiO2 aerogel,photocatalysis,sol-gel method,carbon foam
更新于2025-09-23 15:19:57
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Highly selective fluorescence chemosensor based on carbon-dot-aerogel for detection of aniline gas
摘要： Solid-state fluorescence sensing has become a research hotspot because it is simple and convenient in practical operation. In this study, the carbon dots (CDs)-silica aerogel solid fluorescent material was developed for the selective detection of aniline gas. The blue CDs were prepared by one-step simply hydrothermally treating low-cost sawdust, then CDs-silica aerogel composite material with the high specific surface areas and high porosity was prepared by sol-gel method based on abundant hydroxyl groups on the surface of the CDs which can initiate the gelation of tetraethyl orthosilicate. It is capable of selectively distinguishing toxic gaseous aniline with other volatile organic vapors by sensitive fluorescence quenching, and under optimal conditions, the fluorescence quenching efficiency of aniline gas can reach 76.4%. It is expected that our strategy might provide a new approach for developing a low cost, fast and sensitive CDs-based probe for environmental sensing applications.
关键词： Silica aerogel,Fluorescence chemosensor,Aniline gas,Carbon dots
更新于2025-09-19 17:15:36
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Nanofibrous Kevlar Aerogel Films and Their Phase-Change Composites for Highly Efficient Infrared Stealth
摘要： Infrared (IR) stealth is essential not only in high technology and modern military but also in fundamental material science. However, effectively hiding targets and rendering them invisible to thermal infrared detectors have been great challenges in past decades. Herein, flexible, foldable, and robust Kevlar nanofiber aerogel (KNA) films with high porosity and specific surface area were fabricated first. The KNA films display excellent thermal insulation performance and can be employed to incorporate with phase-change materials (PCMs), such as polyethylene glycol, to fabricate KNA/PCM composite films. The KNA/PCM films with high thermal management capability and infrared emissivity comparable to that of various backgrounds demonstrate high performance in IR stealth in outdoor environments with solar illumination variations. To further realize hiding hot targets from IR detection, combined structures constituted of thermal insulation layers (KNA films) and ultralow IR transmittance layers (KNA/PCM) are proposed. A hot target covered with this combined structure becomes completely invisible in infrared images. Such KNA/PCM films and KNA?KNA/PCM combined structures hold great promise for broad applications in infrared thermal stealth.
关键词： thermal management,aerogel,phase-change materials,free-standing films,Kevlar nanofibers,infrared stealth
更新于2025-09-19 17:15:36
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The preparation and luminescent characters of mesoporouss SiO2/Sm composite materials
摘要： During the mesoporous SiO2 preparation process, Sm3+ ions are dissolved in the anhydrous ethanol solution. The ethanol solution permeates the mesoporous SiO2 then the gel is formed by sol-gel synthesis method. Such, the Sm3+ ions are absolutely introduced into the porous of the mesoporous SiO2 when the gel is dried. In this study, the mesoporous SiO2/Sm3+ composite materials were synthesized by the sol-gel synthesis method. A series of characterization means were used to evaluate the structures of the materials. The near infrared spectrum was used to evaluate the luminescent characteristics. The excitation and emission spectrum of prepared materials showed that the materials had better near infrared luminescent characteristics.
关键词： character,luminescent,rare earth,SiO2 aerogel,sol-gel method
更新于2025-09-19 17:15:36
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Multifunctional inorganic nanomaterial aerogel assembled into fSWNT hydrogel platform for ultraselective NO2 sensing
摘要： Facile fabrication of multifunctional porous inorganic aerogels remains an outstanding challenge despite the considerable demand for extensive applications. Here, we present the production of a multifunctional porous inorganic nanomaterial aerogel by controllable surface chemistry of a functionalized SWNT (fSWNT) hydrogel platform for the first time. The versatile functional inorganic nanoparticles can be incorporated uniformly on the porous 3D fSWNT hydrogel platform through a facile dip coating method at ambient conditions. The morphology of the multifunctional inorganic aerogel is manipulated by designing the fSWNT hydrogel platform for different requirements of applications. In particular, Pt-SnO2@fSWNT aerogels exhibit high porosity and uniformly distributed ultrafine Pt and SnO2 on the fSWNT platform with controllable particle size (1.5–3.5 nm), which result in significantly high surface area (393 m2 g-1). The ultrafine Pt-SnO2@fSWNT aerogels exhibit highly sensitive (14.77% at 5 ppm) and selective NO2 sensing performance even at room temperature due to the increased active surface area and controllable porous structure of the ultrafine aerogel, which can provide fast transport and penetration of a target gas into the sensing layers. The newly designed multifunctional inorganic aerogel with ultrahigh surface area and high open porosity is a prospective materials platform of high performance gas sensors, which could be also broadly expanded to widespread applications including catalysis and energy storages.
关键词： fSWNT hydrogel platform,room temperature sensor,ultraselective NO2 gas sensing,Pt-SnO2@fSWNT aerogel,Multifunctional ultrafine inorganic aerogel
更新于2025-09-19 17:13:59
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A 3D net-like structured fluorescent aerogel based on carboxy-methylated cellulose nanofibrils and carbon dots for a highly effective adsorbent and sensitive optical sensor of Cr(VI)
摘要： To effectively detect and remove Cr(VI) from aqueous solution, a 3D net-like structured fluorescent aerogel was designed and synthesized using highly photoluminescent carbon dots (CDs) and renewable natural carboxy-methylated cellulose nanofibrils (CM-CNF). The surface morphology, microstructure, chemical elements and fluorescence properties of this novel aerogel were studied. Sorption experiments were designed to investigate the sorption properties of Cr(VI) onto this fluorescent aerogel. The adsorption process was described by pseudo-second-order kinetic model and Freundlich model, and the maximum adsorption capacity for Cr(VI) reached 433.5 mg g–1. Furthermore, this novel aerogel emitted bright blue fluorescence with a quantum yield of 11.8 % when applied to Cr(VI) sensing, and a good linear relationship between the quantum yield and Cr(VI) concentration was demonstrated. Accordingly, this novel 3D net-like structured fluorescent aerogel should be a promising smart sorbent for the removal of Cr(VI) with advantages of the 3D net-like structure and rich functional groups that accelerate Cr(VI) sorption and the wrapped fluorescent probe that improves Cr(VI) sensing.
关键词： optical sensor,Cr(VI) removal,3D net-like structured fluorescent aerogel,carboxy-methylated cellulose nanofibrils,carbon dots
更新于2025-09-19 17:13:59