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In this work, we report quantitative morphometry of freeze-dried graphene-based aerogels (i.e., graphene aerogel-GA, nitrogenated GA-NGA, graphene-carbon nanotube hybrid-Gr-MWCNTs, carbon foam-CF, and CF-GA hybrid-CF-GA) and monoliths, prepared by hydrothermal and organic sol-gel methods, respectively. X-ray micro-computed tomography (XMCT) in combination with scanning and transmission electron microscopy allowed visualization of internal microstructures in three-dimensional space. Quantitative morphometry analysis through the reconstructed volume renderings from two-dimensional sliced images revealed hierarchical structures possessing interlaced thin sheets, honeycomb organization, and topological interconnected pore background domains. The influence of small-diameter functionalized multi-walled carbon nanotubes (MWCNTs) inclusions to graphene-like sheets and integration with CF is assessed through quantitative morphometry analysis in terms of volume-weighted pore size, wall thickness, and porosity levels. Hybrid composite porous solids elucidated cross-linking reinforced by a homogeneous distribution of CNTs into complex sheets of GA and CF matrices. A consistent trend impacting porosity and interconnectedness was found following NGA ≥ GA > CF > Gr-MWCNT2:1 > CF-GA > Gr-MWCNT3:1 > Gr-MWCNT5:1, from XMCT image processing and analyses in corroboration with physical properties and reliability. The experimental results provide insights and guide the design of characteristic porous carbonaceous and graphene-based functional nanomaterials for energy sciences, environmental engineering, and fundamental reactive transport of fluids. [ABSTRACT FROM AUTHOR]

Inspired by the back of Namib Desert beetle, 1T-MoS 2 -based aerogel beads enabled harvest water from atmospheric humidity and sustainable freshwater generation from soil, which could alleviate the water shortage in harsh environments. [Display omitted] Freshwater scarcity is one of the most critical issues worldwide, particularly in arid regions, stemming from population growth and climate change. Inspired by the hydrophilic bump structures of desert beetles, 1T-MoS 2 -based aerogel beads with porous structures and CaCl 2- crystal loading (termed as MoAB-m@CaCl 2 -n) were prepared for freshwater harvesting. Metallic-phase MoS 2 nanospheres exhibit excellent photothermal conversion abilities, facilitating solar-driven water desorption and evaporation. Owing to the synergistic effect of its localized surface features, hydrophilic groups, and dispersive CaCl 2 particles, MoAB-2@CaCl 2 -2 efficiently harvests water from atmosphere with a superior moisture adsorption capacity (0.18–0.82 g g−1) at a wide range of relative humidity (10 %-70 %). Under one-sun illumination, MoAB-2@CaCl 2 -2 demonstrates an outstanding solar-driven water evaporation rate of 2.25 kg m-2h−1. The water evaporation rate from soil (water content = 20 %) is 1.19 kg m-2h−1, which is sufficient for sustainable freshwater generation from the soil in arid regions. More importantly, the multifunctional MoAB-2@CaCl 2 -2-based homemade freshwater generation prototype delivers a certain amount of water harvesting (0.99 g g−1 day−1) on a rainy day and provides an impressive daily freshwater yield (53.7 kg m−2) under natural sunlight. The integrated device exhibits excellent efficiency and practicality and offers a feasible method for freshwater harvesting in harsh environments. [ABSTRACT FROM AUTHOR]

[Display omitted] • · Ion doping, morphology control and aerogel construction have been synchronously achieved. • · Zn2+ doping and rGO hybridization can boost the rate performance and cycling stability. • · The ZVOH@rGO electrode demonstrated high reversible capacity of 286.7 mAh g−1 at 30 A g−1. Aqueous zinc-ion batteries (ZIBs) have attracted more and more attention due to their advantages of low cost, high safety and environmental protection. Unfortunately, the unsatisfactory capacity at high current density and long-term cycling performance of cathode materials hinder the development of ZIBs. Here, a novel Zn 0.079 V 2 O 5 ·0.53H 2 O/graphene (ZVOH@rGO) hybrid aerogel composed of ultrathin Zn 0.079 V 2 O 5 ·0.53H 2 O (ZVOH) nanoribbons and 3D continuous graphene conductive network was successfully prepared and used as cathode of ZIBs. Taking advantage of the synergistic effects associated with ion doping, morphology control and unique aerogel structure, the ZVOH@rGO electrode demonstrated ultrafast charge/discharge capability and remarkable cycling stability: A high reversible capacity of 286.7 mAh g−1 was achieved at a current density as large as 30 A g−1, and an impressive capacity retention ratio of 75.6 % was realized over 9800 ultra-long cycles at 12 A g−1. This work is of great significance for the synthesis modification of vanadium oxides and the development of high performance ultrafast charge–discharge ZIBs. [ABSTRACT FROM AUTHOR]

In this study, tetraethylorthosilicate and dimethyldiethoxysilane were employed to modify high-entropy (La 0.2 Y 0.2 Sm 0.2 Eu 0.2 Nd 0.2) 2 Zr 2 O 7 (5RE 2 Zr 2 O 7) ceramic aerogels to address the challenges of particle agglomeration and pore structure collapse that occur during the calcination step in the preparation of high-entropy ceramic aerogels. Following the modification, the specific surface area of the ceramic aerogel increased significantly from 32.22 m2/g to 148.65 m2/g to 201.61 m2/g. Simultaneously, the formation of defective fluorite or pyrochlore crystal structures led to reduced thermal conductivity in the three types of high-entropy ceramic aerogels, namely 5RE 2 Zr 2 O 7 (from 0.212 W m−1•K−1 to 0.139 W m−1•K−1), 5RE 2 ZSA (from 0.065 W m−1•K−1 to 0.049 W m−1•K−1), and DDS/5RE 2 ZSA (from 0.046 W m−1•K−1 to 0.039 W m−1•K−1), compared to their respective non-high-entropy counterparts. Balancing the porous structure of high-entropy ceramic aerogels with an adequate number of defective fluorite or pyrochlore crystals is challenging. Addressing this challenge is a key direction for advancing high-entropy aerogels in the future. [Display omitted] [ABSTRACT FROM AUTHOR]

Lightweight phenolic matrix composites are highly potential in ablative thermal protective materials for future aerospace vehicles, and hybrid modification is considered as one of effective ways to improve the oxidation and ablation resistance of phenolic matrix. Herein, the co-continuous silica zirconium hybrid phenolic resin (SZRx) was synthesized, which can be used to prepare lightweight ablation resistant aerogel composites by the sol-gel method. The SZRx aerogel showed stable porous structure and excellent hydrophobicity, and the silicon zirconium hybrid greatly improved the high temperature carbon residue and oxidation resistance of phenolic resin. The SZRx aerogel composites also possessed excellent integrated characteristics of heat protection and insulation, with a linear ablation rate as low as 0.032 mm/s and a back temperature below 200 °C. The synergistic effect of silicon and zirconium formed the multiphase ceramic layer (C, SiO 2 , SiC and ZrO 2) with the sea-island-like structure on the surface of the composite material, which can effectively resist high-temperature ablation and aerodynamic exfoliation. This can indicate that silicon zirconium dual element hybrid phenolic resin is the highly competitive matrix for lightweight and ablation resistant composite materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Different sorbents, including activated carbons, an Ag-aerogel, Ag-xerogels, an Ag-alumina, an Ag-zeolite, a Ag2S-polyacrylonitrile composite, and a carbon foam were investigated for static I2(g) loading at 71 °C for 56 d followed by 4.7 d of desorption. The iodine loadings were 630–1249 mg g−1 for activated carbons and 87–744 mg g−1 for other sorbents. [ABSTRACT FROM AUTHOR]

As a dual-functional catalyst for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), Ru clusters have great potential, but there are certain difficulties regarding their stability on the substrate and the tunability of their electronic environment. Here, the S doped graphited biochar aerogel electrocatalyst was designed and synthesized using terrestrial lignin and algal polysaccharide as a carbon substrate. The Ru clusters were anchored on the S-doped carbon aerogel (P-Ru/SC) by carefully designing the Ru-S bond via a novel plasma assisted high temperature carbonization treatment. The optimized P-Ru/SC-2 catalyst exhibits excellent electrocatalytic performance for the HER and OER, achieving ultra-small overpotentials of 119.6 mV and 193.4 mV at 10 mA cm-2. The dual-electrode requires only 1.47 V to reach 10 mA cm-2. It is worth noting that a large number of S sites on graphited carbon can strongly interact with the Ru clusters, significantly improving the catalytic activity and stability for the HER and OER. [ABSTRACT FROM AUTHOR]

N-doped carbon aerogel capsulated Co3O4 (Co3O4@NCA) is prepared via a hydrothermal method using an N-doped carbon aerogel (NCA) as a conductive carbon matrix and coating layer. Kinetic parameters are investigated using CV and GITT methods, and the improved performance could be ascribed to rapid lithium-ion diffusion and enhanced pseudocapacitance contribution induced by the introduction of carbon aerogel conductive matrices and the construction of porous nanomicro-hierarchical architectures, which endow the material with a large surface area, good conductivity, abundant pore channels, and plentiful defects and active sites, thus greatly increasing the lithium storage capacity. Used as an anode for lithium-ion batteries, Co3O4@NCA-1 displays a reversible capacity of 600.2 mA h g-1 during the 200th cycle under 100 mA g-1, 5.13 times larger than the specific charge capacity of 116.8 mA h g-1 for Co3O4 samples. Even if the current density is increased to 1 A g-1, it has 4.48 times the charge capacity of pure Co3O4. The Co3O4 modification strategy using NCA as a matrix to fabricate nanomicro-hierarchical architectures demonstrates potential applications in the energy storage field. [ABSTRACT FROM AUTHOR]

Boron nitride (BN) aerogels, dual interconnecting network of BN nanoscale building blocks, and plenty of air within these nanoscale building blocks, have great potential in many emerging fields. However, fast synthesis and emerging applications, e.g., information encryption, are still challenging for advancing BN aerogels. Herein, intrinsic photoluminescent BN aerogels with programmable patterns are developed via laser ablating of melamine diborate (M2B) aerogel. The obtained BN aerogel exhibited typical hollow‐microsphere structures and blue fluorescence phenomenon, which are totally different from BN aerogels reported elsewhere. This BN aerogel exhibited excellent thermal insulation properties (0.027 W mK−1), transient fluorescence feature (3 ns average radiative lifetime), high quantum yield (18.45%), and excellent weather ability (e.g., resistance to high temperature, solar irradiation, and humidness). By programming the laser moving path, different fluorescent patterns (e.g., various security labels, secret matching keys, quick response codes) of BN aerogels can be processed, which promises excellent information encryption in the field of Internet of Things, etc. The results may inspire researchers to fabricate more aerogels with this fast laser‐ablation strategy and the resulting intrinsic fluorescent BN aerogels may find significant applications in some emerging fields. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerator (TENG) has emerged as a novel nanotechnology for energy harvesting and self‐powered sensing via utilizing various low‐frequency mechanical energies throughout the surrounding environment. However, designing TENG with high physical robustness, flexibility, and output performance is rather challenging. This study develops monolithic conjugated microporous polymer aerogel (CMPA) with delocalized π‐conjugation to construct TENG with a robust porous structure. The as‐produced CMPA is composed of hollow intertwined nanotubes with a high degree of flexibility and high specific surface area (up to 528 m2 g−1). Due to its intrinsic nature of conjugated electron transfer and architectural characteristics, the CMPA‐based TENG (effective area: 4.9 cm2) shows a high sensitivity to mechanical force and excellent electric output (open‐circuit voltage: 72 V, short‐circuit peak current: 3.2 µA and transferred charge: 48 nC). Moreover, the CMPA‐based TENG can charge micro‐electronic devices and sense human motions. This work will inspire the design of aerogel‐based electronic devices and the management of renewable energy resources. [ABSTRACT FROM AUTHOR]

Flexible bioelectronics have a large range of applications in the field of human health monitoring and human‐machine interfaces. Among various bioelectronics, flexible electrodes have been widely studied. However, it is still lack of investigation in the development of electrodes with high signal quality and long service life. Here, a sponge inspired flexible electrode based on cellulose aerogel is developed via thermally induced phase separation. Due to its flexibility, the electrode can easily conform to skin and achieve a higher signal‐to‐noise ratio (SNR) than the commercial rigid electrode. At the same time, the aerogel electrode with a sponge‐like structure can absorb solutions several times their own weight (≈800%). In addition, the dope of polypyrrole coated silver nanowires (AgNWs@PPy) improves its intrinsic bactericidal activity (antibacterial rate above 97.8%) and the cellulose‐based material itself offers good skin compatibility. Therefore, all these features contribute to a longer service life, while has been proven in electrophysiological signals recording. The SNR of electrocardiogram (ECG) signals recorded by aerogel electrode in 24 h is ≈15% higher than that of commercial electrode. Apart from that, when the commercial electrode is unavailable for eye‐open (EO) and eye‐closed (EC) paradigm in 12 h, the aerogel electrode can still record clear electroencephalogram (EEG) features. [ABSTRACT FROM AUTHOR]

Hierarchical microarchitecture engineering is a state‐of‐the‐art approach to designing aerogel electromagnetic (EM) wave absorbers, offering huge potential in improving EM energy dissipation. However, the intrinsic feedback mechanism regarding the specific influence of each microarchitecture parameter on EM properties is not comprehensively revealed, making it challenging to fully utilize the potential of aerogels to achieve superior EM wave absorption performance. Herein, a range of MXene/rGO‐based aerogels with multilevel hierarchical configurations are fabricated by a magnetic field‐guided strategy. Leveraging growth thermodynamics effects under a magnetic field and bridging effect between adjacent rGO units, three hierarchical microarchitecture models (lamellae ordering, interlayer spacing, and layer thickness) are constructed in aerogels. Remarkably, three models progressively improve reflection loss (RL), effective absorption bandwidth (EAB), and matching thickness by enhancing dielectric loss, decoupling attenuation‐impedance matching, and adjusting power loss density, respectively. Consequently, the MXene/rGO‐based aerogels exhibit stepwise enhancement in EM wave performance, achieving a superior RL of −64.6 dB and a broad EAB of 7.0 GHz at 1.8 mm thickness, surpassing alternative aerogels with other configurations. This work elucidates the effect of multilevel hierarchical microarchitecture on the synergistic multi‐effect dissipation mechanism of EM waves in aerogels, providing insights for designing advanced EM absorbers through diverse strategies. [ABSTRACT FROM AUTHOR]

Uncontrolled dendrite growth and electrolyte‐induced intricate parasitic reactions are two great challenges that hinder the commercial applications of aqueous zinc‐ion batteries. Herein, a synchronous modulation strategy for Zn2+ interfacial migration behavior and electrolyte microenvironment is proposed by constructing a functional lanthanum hydroxide aerogel (LAG) interface layer on Zn anode surface. The in situ derivation of ion‐conducting zinc hydroxide sulfate (ZHS) from LAG layer results in the spontaneous generation of a hierarchic interface layer during the plating process, where the high Zn2+ selectivity of the upper dense ZHS layer can limit SO42− migration and allow for fast Zn2+ interfacial migration kinetics, while the aerogel layer with well‐defined nanochannels near the anode side can homogenize Zn2+ distribution, thus leading to the effective suppression of both dendrites and side reactions. Additionally, the pH microenvironment of the acidic electrolyte can be synchronously regulated by slightly soluble La(OH)3 aerogel, further inhibiting electrolyte corrosion and HER. Consequently, the modified Zn anode delivers highly reversible Zn plating/stripping and low‐voltage hysteresis, and the high areal‐capacity Zn||MnO2 full cells demonstrate considerable electrochemical performances under high Zn utilization conditions. This functional aerogel‐driven synchronous modulation strategy of Zn2+ migration behavior and electrolyte microenvironment provides new insight for stabilizing Zn metal anodes. [ABSTRACT FROM AUTHOR]

In this study, a top-down approach was employed for the fabrication of flame-retardant wood aerogels. The process involved the removal of lignin and the removal of hemicellulose utilizing NaOH concomitantly with the incorporation of ZnO and urea. Subsequently, an in situ reaction with boric acid was conducted to prepare flame-retardant wood aerogels. The morphology, chemical composition, thermal stability, and flame retardancy of the samples were studied. The results show that the NaOH treatment transformed the wood into a layered structure, and flame-retardant particles were uniformly distributed on the surface of the aerogel. The peak heat release rate (PHRR) and total heat release (THR) of the flame-retardant aerogel were significantly reduced compared with the control samples. Meanwhile, its vertical burning test (UL-94) rating reached the V-0 level, and the Limiting Oxygen Index (LOI) could exceed 90%. The flame-retardant wood aerogel exhibited excellent flame retardancy and self-extinguishing properties. [ABSTRACT FROM AUTHOR]

Porous media such as aerogels can exhibit unique properties including low thermal conductivity, low bulk density, and low sound velocity. However, the limited mechanical properties of aerogels restrict their widespread application. This study focuses on understanding the mechanical behavior of aggregated silica aerogels by investigating their microstructural connectivity and densification mechanisms under uniaxial compression. The interparticle connectivity is generated using the diffusion‐limited cluster–cluster aggregation (DLCA) algorithm, and the particle connections are modeled by beam elements that account for contact interaction. The mechanical response of representative volume elements (RVEs) is analyzed in both linear and nonlinear regimes while applying periodic boundary conditions. The model is correlated with experimental compression test data to validate the simulation results. With increasing compressive strain, load transitions between multiple backbone paths appear in the network structure. Thus, the simulation model provides insight into the compression process. Moreover, the simulation model enables the examination of the influence of various model parameters and facilitates the evaluation of the power–law relationship between the elasticity modulus and porosity of aerogels. [ABSTRACT FROM AUTHOR]

The development of the industry has increased the demand for energy storage, making the provision of energy storage devices essential. The supercapacitor is one of the potential energy storage devices, and carbon aerogel (CA) is a promising candidate for supercapacitor electrode fabrication. Ni-doped nipa palm shell-derived CA (Ni-NS-CA) was used to fabricate the electrode for supercapacitors to save production costs and utilize biomass wastes. Ni-NS-CA was synthesized via a three-step process: Hydrogel making through cross-linking (SA, Ni2+), freeze-drying, and pyrolysis. The characteristics of Ni-NS-CA are analyzed using a scanning electron microscope, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, Raman spectroscopy, and Nitrogen adsorption–desorption isotherm 77 K. The electrochemical properties of Ni-NS-CA was analyzed via cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. With stable energy storage results (104.15 F g−1) and the electrochemical system based on Ni-NS-CA extends its application to Hg2+ sensing. Moreover, Ni-NS-CA was a potential material to solve oil spills, which has an oil adsorption capacity of 31.24 g g−1. [ABSTRACT FROM AUTHOR]

[Display omitted] • Developed an ultrahigh-strength silicone aerogel with an innovative armor-like epoxy framework using a temperature-controlled sequential reaction strategy. • Achieved superior mechanical properties in the aerogel with compressive modulus ranging from 37.8 to 244.3 MPa, significantly surpassing other polymer-reinforced silicone aerogels. • The aerogel demonstrates exceptional thermal insulation, maintaining a low thermal conductivity of 0.025 to 0.051 W m−1 K−1 and maintains thermal characteristics across a temperature range of −20 to 300 °C. • Enhanced aerogel composites exhibit significantly improved mechanical strength while maintain low thermal conductivities, further expanding their practical applications in various industries. Aerogels with low density and high porosity are extremely attractive for high-performance insulation, but their brittleness, complicated fabrication, and poor mechanical properties greatly limit their practical applications. Herein, we report an ultrahigh-strength silicone aerogel with an armor-like epoxy framework via a temperature-controlled sequential reaction strategy. The key to this synthesis is forming a Si-O-Si framework via the polycondensation of silanes at 100 °C, followed by in-situ armoring an epoxy framework via an intermolecular cyclization at an elevated temperature of 150 °C. Owing to the enhanced framework, the resulting aerogel could withstand capillary tension in the drying process, enabling it to be dried at ambient pressure without shrinkage. The obtained aerogel possesses a tunable density of 0.17–0.45 g/cm3 and ultrahigh-strength with compressive modulus up to 37.8–244.3 MPa, which surpasses other polymer-reinforced silicone aerogels by a factor of five in mechanical properties. It also demonstrates outstanding thermal insulation, with an extremely low thermal conductivity from 0.025 to 0.051 W m−1 K−1 at room temperature, and maintains thermal characteristics across a temperature range of −20 to 300 °C. Furthermore, the aerogel composites prepared by the reinforcement of low-density fiber mats have tunable densities of 0.36–0.87 g/cm3, much enhanced tensile strengths of 15.9–72.3 MPa, and low thermal conductivities at room temperature of 0.042–0.078 W m−1 K−1. This study presents a cost-effective method for enhancing the production of silicone aerogel materials, offering considerable opportunities for their application in insulation, energy transport, and the aerospace sector. [ABSTRACT FROM AUTHOR]

As promising candidates for widespread application, advanced ceramic fiber mats with robust mechanical properties are urgently needed. However, the brittleness, fatigue failure, and large density of ceramic fiber pose significant obstacles to its practical application. Herein, a novel SiO2 aerogel/ZrO2 composite nanofibrous membrane (SZCNFM) with excellent flexibility was prepared by introducing SiO2 aerogel nanoparticles into ZrO2 nanofiber via simple co‐electrospinning. The developed tetragonal zirconia phase without changing up to 1200°C endows SZCNFM material with excellent thermal stability. Furthermore, the as‐prepared membranes exhibit fatigue resistance ability which can maintain 98% of the original stress after 100 buckling cycle tests. The addition of mesoporous structure aerogel reduces the heat transfer of the nanofibrous membrane, giving its low thermal conductivity (30 mW/m/K) and low‐frequency sound absorption (noise reduction coefficient of 0.52). Combined with the high‐temperature resistance, low thermal conductivity and excellent sound‐absorption ability make it a promising material for heat insulation and acoustic absorption. [ABSTRACT FROM AUTHOR]

In this study, monolithic Al 2 O 3 –SiO 2 aerogels with excellent thermal stability were synthesized by ambient pressure drying (APD) or supercritical drying (SCD) using tetraethyl orthosilicate and boehmite nanorods (L = 20–30 nm, D = 3–5 nm) as precursors. The high specific surface area of aerogels prepared by APD or SCD was maintained after calcination at 800 °C (585 m2/g or 664 m2/g), 1000 °C (415 m2/g or 487 m2/g), and 1100 °C (175 m2/g or 231 m2/g). The anti-sintering mechanism of the aerogels prepared with boehmite nanorods as the aluminum source was discussed in detail. Successful preparation by APD offers the possibility of low-cost and large-scale application of monolithic Al 2 O 3 –SiO 2 aerogels. Al 2 O 3 –SiO 2 aerogels with excellent thermal stability have the potential to be used as high-temperature thermal insulating materials in aerospace applications. [ABSTRACT FROM AUTHOR]

The formation of shape-stabilized composite phase change materials (CPCMs) with special structure is an efficient strategy to prevent the leakage of phase change materials (PCMs) and improve the solar-thermal conversion ability. In this work, graphene and boron nitride nanosheets (BBNS) were prepared by the magnesiothermic reduction SHS method in CO 2 and N 2 atmosphere, respectively. Then, an anisotropic and hierarchical porous boron nitride/graphene aerogel with three-dimensional network was constructed by directional ice-freezing method using carboxymethyl cellulose as supporting framework and adhesive, and polyethylene glycol (PEG) was impregnated to prepare novel CPCMs. The CPCMs had enthalpies of 150∼160 J/g, and a highest thermal conductivity of 0.390 W/(m·K), which was around 47% higher than that of pure PEG. The ability of the CPCMs to convert solar energy to thermal energy was significantly enhanced. Under a simulated light intensity of sunlight (100 mW/cm2), its solar-thermal conversion efficiency reaches 94.92%, and after 20 min of irradiation, the surface temperature can reach 72 °C. These CPCMs are promising for the efficient use of renewable solar energy due to their high solar-thermal conversion efficiency and thermal storage capabilities. [ABSTRACT FROM AUTHOR]

Highlights: Typical structures/working mechanisms of gel-based triboelectric nanogenerators and performance advantages of gel materials reviewed. Optimization of hydrogels, organogels, and aerogels for triboelectric nanogenerators in flexible sensing summarized. Applications, challenges, and future development directions of gel-based triboelectric nanogenerators in flexible sensing are discussed. The rapid development of the Internet of Things and artificial intelligence technologies has increased the need for wearable, portable, and self-powered flexible sensing devices. Triboelectric nanogenerators (TENGs) based on gel materials (with excellent conductivity, mechanical tunability, environmental adaptability, and biocompatibility) are considered an advanced approach for developing a new generation of flexible sensors. This review comprehensively summarizes the recent advances in gel-based TENGs for flexible sensors, covering their principles, properties, and applications. Based on the development requirements for flexible sensors, the working mechanism of gel-based TENGs and the characteristic advantages of gels are introduced. Design strategies for the performance optimization of hydrogel-, organogel-, and aerogel-based TENGs are systematically summarized. In addition, the applications of gel-based TENGs in human motion sensing, tactile sensing, health monitoring, environmental monitoring, human–machine interaction, and other related fields are summarized. Finally, the challenges of gel-based TENGs for flexible sensing are discussed, and feasible strategies are proposed to guide future research. [ABSTRACT FROM AUTHOR]

Ceramic aerogels are gaining increasing attention due to their low density, high‐temperature resistance, and excellent chemical stability. However, conventional ceramic aerogels are hindered by their intrinsic brittleness and limited dielectric properties, which restrict their scalable manufacturing and multifunctional applications. Here, ultralight, biomimetic porous, electrically and magnetically conductive ceramic nanofibrous aerogels composed of silicon dioxide (SiO2) nanofibers, graphene, and metal–organic framework (MOF) derivatives are prepared through an ice‐templating freeze‐casting followed by annealing approach. The renewable SiO2 nanofibers form robust bonding points with graphene, constructing interconnected high‐porosity aerogels with good mechanical resilience. This allows for efficient integration of MOF‐derived magnetic nanoparticles associated with a synergistic mechanical enhancement. The synergies of the dielectric and magnetic components, combined with the uniformly arranged sheet‐like cell walls which facilitate the outstanding electromagnetic wave absorption performance. Moreover, the hydrophobic ceramic aerogels showcase excellent magnetothermal conversion, contributing to the application in wireless therapy, antibacterial, and magnetothermal deicing. Furthermore, the nanofibrous aerogels exhibit good thermal stability and insulation properties, rendering them highly suitable for thermal management devices in extreme conditions. With the renewable, convenient, and scalable manufacturing method, these multifunctional ceramic nanofibrous aerogels thus hold great promise in electromagnetic protection, wireless heating, and next‐generation thermal management devices. [ABSTRACT FROM AUTHOR]

Efficient heat transfer control is highly demanded for dynamic thermal management of equipment and buildings especially when the environmental temperature dramatically changes. Thermal switches, the current approach of heat transfer control, suffer from the issues of low switching ratios below eight and sharp state transition between "on" and "off". Herein, a continuously‐tuned thermal regulator with an ultrahigh thermal‐conductivity change ratio of 43 based on superaligned carbon nanotube aerogel is reported, which works on the regulation of both thermal interfacial resistance and conduction pathways by compressive deformation‐induced microstructure evolution. This thermal regulator can stabilize the device temperature at 25 °C when the environmental temperature varies by 7 and 11 °C under the natural convection and forced convection conditions, respectively. Toward practical application, the thermal regulator with flexibility is wrapped around a cylindrical lithium‐ion battery to control the operation temperature within the optimal range of 20–40 °C for enhanced discharging performance even at an environmental temperature of −20 °C. Besides, by combining the thermal regulator with radiative cooling film, the house model temperature can be lowered by 2.7 °C during daytime and raised by 1.1 °C during nighttime compared with the bare one. This efficient thermal regulation approach offers an effective solution for practical thermal management. [ABSTRACT FROM AUTHOR]

Highlights: The homogeneous hybridization of organic–inorganic-metal elements in 3D aerogel was achieved by an expeditious method. The aerogel tightly integrates excellent thermal insulation (49.6 mW m−1 K−1), ablative resistance, mechanical strength, and superhydrophobic properties. The ablated carbon aerogel combines notable electromagnetic interference shielding properties (31.6 dB) and load-carrying properties (272.8 kN·m kg−1). Vehicles operating in space need to withstand extreme thermal and electromagnetic environments in light of the burgeoning of space science and technology. It is imperatively desired to high insulation materials with lightweight and extensive mechanical properties. Herein, a boron–silica–tantalum ternary hybrid phenolic aerogel (BSiTa-PA) with exceptional thermal stability, extensive mechanical strength, low thermal conductivity (49.6 mW m−1 K−1), and heightened ablative resistance is prepared by an expeditious method. After extremely thermal erosion, the obtained carbon aerogel demonstrates noteworthy electromagnetic interference (EMI) shielding performance with an efficiency of 31.6 dB, accompanied by notable loading property with specific modulus of 272.8 kN·m kg−1. This novel design concept has laid the foundation for the development of insulation materials in more complex extreme environments. [ABSTRACT FROM AUTHOR]

Improving interface connectivity of magnetic nanoparticles in carbon aerogels is crucial, yet challenging for assembling lightweight, elastic, high‐performance, and multifunctional carbon architectures. Here, an in situ growth strategy to achieve high dispersion of metal–organic frameworks (MOFs)‐anchored cellulose nanofibrils to enhance the interface connection quality is proposed. Followed by a facile freeze‐casting and carbonization treatment, sustainable biomimetic porous carbon aerogels with highly dispersed and closely connected MOF‐derived magnetic nano‐capsules are fabricated. Thanks to the tight interface bonding of nano‐capsule microstructure, these aerogels showcase remarkable mechanical robustness and flexibility, tunable electrical conductivity and magnetization intensity, and excellent electromagnetic wave absorption performance. Achieving a reflection loss of −70.8 dB and a broadened effective absorption bandwidth of 6.0 GHz at a filling fraction of merely 2.2 wt.%, leading to a specific reflection loss of −1450 dB mm−1, surpassing all carbon‐based aerogel absorbers so far reported. Meanwhile, the aerogel manifests high magnetic sensing sensibility and excellent thermal insulation. This work provides an extendable in situ growth strategy for synthesizing MOF‐modified cellulose nanofibril structures, thereby promoting the development of high‐value‐added multifunctional magnetic carbon aerogels for applications in electromagnetic compatibility and protection, thermal management, diversified sensing, Internet of Things devices, and aerospace. [ABSTRACT FROM AUTHOR]

Uncontrollable massive bleeding caused by trauma will cause the patient to lose a large amount of blood and drop body temperature quickly, resulting in hemorrhagic shock. This study aims to develop a hemostatic product for hemorrhage management. In this study, waste pomelo peel as raw material is chosen. It underwent processes of carbonization, purification, and freeze‐drying. The obtained carbonized pomelo peel (CPP) is hydrophilic and exhibits a porous structure (nearly 80% porosity). The water/blood absorption ratio is significantly faster than the commercial Gelfoam and has a similar water/blood absorption capacity. In addition, the CPP showed a water‐triggered shape‐recoverable ability. Moreover, the CPP shows ideal cytocompatibility and blood compatibility in vitro and favorable tissue compatibility after long terms of subcutaneous implantation. Furthermore, CPP can absorb red blood cells and fibrin. It also can absorb platelets and activate platelets, and it is capable of achieving rapid hemostasis on the rat tail amputation and hepatectomized hemorrhage model. In addition, the CPP not only can quickly stop bleeding in the rat liver‐perforation and rabbit heart uncontrolled hemorrhage models, but also promotes rat liver and rabbit heart tissue regeneration in situ. These results suggest the CPP has shown great potential for managing uncontrolled hemorrhage. [ABSTRACT FROM AUTHOR]

Aerogels, as kinetic energy absorbing materials, can find crucial applications for safeguarding in transportation, sports, buildings, construction, and aerospace. However, the highly porous structure makes it extremely fragile for endurance usage. In this study, a half‐full filled structure has been proposed, and the concept has been demonstrated based on shear thickening fluid (STF) and chemically vapor deposited carbon nanotube aerogels (CNTAs), in which the outer part of CNTA is filled with STF while the inner core keeping unfilled. Chemical vapor deposition significantly enhances the elasticity and electromagnetic shielding performance of the native CNTA. The half‐full filled aerogels (HFFA) show a 348% increase in energy absorption compared to the CNTA. At the same time, the density, electronic conductivity, and electromagnetic interference shielding effectiveness (EMI SE) of the HFFAs are 0.117 g cm−3, 1213 S m−1, and 69.52 dB (which is a neglectable reduction of 0.63% compared to native CNTA), respectively. The HFFA strategy provides an alternative route to fabricate robust aerogels with a remarkable increase of target properties while maintaining other properties, such as low density, high pore volume, and conductivity, with limited changes. [ABSTRACT FROM AUTHOR]

Three‐dimensional asymmetric supercapacitors (3D ASC) have garnered significant attention due to their high operating window, theoretical energy density, and circularity. However, the practical application of 3D electrode materials is limited by brittleness and excessive dead volume. Therefore, we propose a controlled contraction strategy that regulates the pore structure of 3D electrode materials, eliminates dead volume in the 3D skeleton structure, and enhances mechanical strength. In this study to obtain reduced graphene oxide/manganese dioxide (rGO/MnO2) and reduced graphene oxide/carbon nanotube (rGO/CNT) composite aerogels with a stable and compact structure. MnO2 and CNT as nanogaskets, preventing the self‐stacking of graphene nanosheets during the shrinkage process. Additionally, the high specific capacitor nanogaskets significantly enhance the specific energy density of the rGO aerogel electrode. The prepared rGO/MnO2//rGO/CNT 3D ASC exhibits a high mass‐specific capacitance of 216.15 F g−1, a high mass energy density of 74 Wh kg−1 at 3.5 A g−1, and maintains a retention rate of capacitance at 99.89 % after undergoing 10,000 cycles of charge and discharge at 5 A g−1. The versatile and integrated assembly of 3D ASC units is achieved through the utilization of the robust mechanical structure of rGO‐based aerogel electrodes, employing a mortise and tenon structural design. [ABSTRACT FROM AUTHOR]

Covalent organic frameworks (COFs) possess intrinsic nanoscale pores, limiting mass transport and impacting their utility in many applications, such as catalysis, supercapacitors, and gas storage, demanding efficient diffusion throughout the material. Hierarchical porous structures, integrating larger macropores with inherent micro‐/meso‐pores, facilitate rapid mass transport. Recently, the fabrication of aerogel monoliths is reported exclusively from imine‐linked COFs, offering flexibility in aerogel composition. However, challenges in synthesizing robust β‐ketoenamine‐based COFs with comparable surface areas prompted innovative synthetic approaches. Leveraging the dynamic nature of COF bonds, in this work efficient monomer exchange from imine to partially β‐ketoenamine‐linked COFs within the gel phase is demonstrated. These aerogels can be transformed into electrodes using the compression technique. The new flexible electrodes‐based β‐ketoenamine‐linked COF composites with C super P exhibit superior durability and redox activity. Through supercapacitor assembly, the β‐ketoenamine‐linked COF electrodes outperform their imine‐based counterparts, showcasing enhanced capacitance (88 mF cm−2) and stability at high current densities (2.0 mA cm−2). These findings underscore the promise of β‐ketoenamine‐linked COFs for pseudocapacitor energy storage applications. [ABSTRACT FROM AUTHOR]

In our previous work, inspired by the Origami theory, folded graphene oxide aerogel (fGA) with the arch morphology was successfully prepared. However, the self-folding mechanism of folded graphene oxide (fGO) and the enhancement mechanism of the interlayer interface were hard to be explained. Therefore, building on previous work, this study adopted a multiscale modeling approach. By using the molecular dynamics (MD) method, the folding mechanism of fGO was investigated on a microscopic scale. The effect of fGO microstructure on mechanical properties was also studied. GO folding was attributed to Cu2+ coordination and electrostatic interactions. Compared to GO, fGO showed better mechanical property parameters. Furthermore, the mechanical behavior of the samples was researched on a macroscopic scale. The connection points between the sheet layers increased and became tighter when the fGA structure was stressed. The strength and resistance to deformation of the aerogel became strong and stabilized the structure. The interfacial bonds were mainly enhanced in the interlayer by the increase of hydrogen bonding (H bond) and van der Waals forces (vdW). Thus, the multiscale modeling approach was of theoretical guidance for the improvement of the mechanical properties of fGA. [ABSTRACT FROM AUTHOR]

Polypropylene-based aerogels with high surface area have been developed for the first time. By chemical crosslinking of polypropylene with oligomeric capped-end amino compounds, followed by dissolution, thermally induced phase separation, and the supercritical CO2 drying process or freeze-drying method, the aerogels exhibit high specific surface areas up to 200 m2/g. Moreover, the silica-cage multi-amino compound was utilized in a similar vein for forming hybrid polypropylene aerogels. According to the SEM, the developed polypropylene-based aerogels exhibit highly porous morphology with micro-nanoscale structural features that can be controlled by processing conditions. Our simple and inexpensive synthetic strategy results in a low-cost, chemically resistant, and highly porous material that can be tailored according to end-use applications. [ABSTRACT FROM AUTHOR]

Cellulose-based biomass aerogels recently have garnered significant attentions as emerging materials for water treatment, due to their excellent characteristics of high porosity, lightweight structure, chemical modifiability and environmental friendliness. However, conventional freeze-drying methods have resulted in disordered pore structures of aerogels, reducing their mechanical property and water treatment efficiency. This article aims to provide a comprehensive review on the role of freeze-drying in cellulose-based aerogels. Special emphases are placed on freezing optimization strategies in aerogels preparations, such as co-solvent addition, directional freezing, freeze-thaw and soft-ice freezing, and water treatment applications of aerogels including oil-water separation, dye and heavy metal ions adsorptions, and seawater desalination via photothermal interfacial evaporation. The ordered pore structure constructed by freezing optimization can significantly increase the specific surface area and enhance the mechanical property of aerogels, thus improving the mass transfer rate and recyclability. The high-performance biomass aerogels prepared through freezing optimizations have shown a great application promise for biomass resources to achieve green and sustainable water treatment processes. [ABSTRACT FROM AUTHOR]

A novel Cr-doped BaTiO3 aerogel was successfully synthesized using a co-gelation technique that involves two metallic alkoxides and a supercritical drying method. This freshly prepared aerogel has a high specific surface area of over 100 m2/g and exhibits improved responsiveness to the simulated sunlight spectrum. Methyl orange (MO) was chosen as the simulated pollutant, and the results reveal that the Cr-doped BaTiO3 aerogel, when modified with the noble metal silver (Ag), achieves a pollutant removal rate approximately 3.2 times higher than that of the commercially available P25, reaching up to 92% within 60 min. The excellent photocatalytic performance of the Ag-modified Cr-doped BaTiO3 aerogel can be primarily attributed to its extensive specific surface area and three-dimensional porous architecture. Furthermore, the incorporation of Ag nanoparticles effectively suppresses the recombination of photo-generated electrons and holes. Stability and reusability tests have confirmed the reliability of the Ag-modified Cr-doped BaTiO3 aerogel. Therefore, this material emerges as a highly promising candidate for the treatment of textile wastewater. [ABSTRACT FROM AUTHOR]

In recent years, flexible pressure sensors have received considerable attention for their potential applications in health monitoring and human–machine interfaces. However, the development of flexible pressure sensors with excellent sensitivity performance and a variety of advantageous characteristics remains a significant challenge. In this paper, a high-performance flexible piezoresistive pressure sensor, BC/ZnO, is developed with a sensitive element consisting of bacterial cellulose (BC) nanofibrous aerogel modified by ZnO nanorods. The BC/ZnO pressure sensor exhibits excellent mechanical and hydrophobic properties, as well as a high sensitivity of −15.93 kPa−1 and a wide range of detection pressure (0.3–20 kPa), fast response (300 ms), and good cyclic durability (>1000). Furthermore, the sensor exhibits excellent sensing performance in real-time monitoring of a wide range of human behaviors, including mass movements and subtle physiological signals. [ABSTRACT FROM AUTHOR]

The use of solar interface evaporation for seawater desalination or sewage treatment is an environmentally friendly and sustainable approach; however, achieving efficient solar energy utilization and ensuring the long-term stability of the evaporation devices are two major challenges for practical application. To address these issues, we developed a novel ceramic fiber@bioderived carbon composite aerogel with a continuous through-hole structure via electrospinning and freeze-casting methods. Specifically, an aerogel was prepared by incorporating perovskite oxide (Ca0.25La0.5Dy0.25)CrO3 ceramic fibers (CCFs) and amylopectin-derived carbon (ADC). The CCFs exhibited remarkable photothermal conversion efficiencies, and the ADC served as a connecting agent and imparted hydrophilicity to the aerogel due to its abundant oxygen-containing functional groups. After optimizing the composition and microstructure, the (Ca0.25La0.5Dy0.25)CrO3 ceramic fiber@biomass-derived carbon aerogel demonstrated remarkable properties, including efficient light absorption and rapid transport of water and solutes. Under 1 kW m−2 light intensity irradiation, this novel material exhibited a high temperature (48.3 °C), high evaporation rate (1.68 kg m−2 h−1), and impressive solar vapor conversion efficiency (91.6%). Moreover, it exhibited long-term stability in water evaporation even with highly concentrated salt solutions (25 wt%). Therefore, the (Ca0.25La0.5Dy0.25)CrO3 ceramic fiber@biomass-derived carbon aerogel holds great promise for various applications of solar interface evaporation. [ABSTRACT FROM AUTHOR]

Regulation of excessive inflammation and impaired cell proliferation is crucial for healing diabetic wounds. Although plant‐to‐mammalian regulation offers effective approaches for chronic wound management, the development of a potent plant‐based therapeutic presents challenges. This study aims to validate the efficacy of turmeric‐derived nanoparticles (TDNPs) loaded with natural bioactive compounds. TDNPs can alleviate oxidative stress, promote fibroblast proliferation and migration, and reprogram macrophage polarization. Restoration of the fibroblast–macrophage communication network by TDNPs stimulates cellular regeneration, in turn enhancing diabetic wound healing. To address diabetic wound management, TDNPs are loaded in an ultralight‐weight, high swelling ratio, breathable aerogel (AG) constructed with cellulose nanofibers and sodium alginate backbones to obtain TDNPs@AG (TAG). TAG features wound shape‐customized accessibility, water‐adaptable tissue adhesiveness, and capacity for sustained release of TDNPs, exhibiting outstanding performance in facilitating in vivo diabetic wound healing. This study highlights the potential of TDNPs in regenerative medicine and their applicability as a promising solution for wound healing in clinical settings. [ABSTRACT FROM AUTHOR]

The development of nano-energetic materials has significantly advanced, leading to enhanced properties and novel applications in areas such as aerospace, defense, energy storage, and automobile. This research aims to engineer multi-dimensional nano-energetic material systems with precise control over energy release rates, spatial distribution, and temporal and pressure history. In this context, sol–gel processing has been explored for the manufacture of nanocomposite aluminum thermites using aerogels. The goal is to produce nano-thermites (Al/Fe2O3) with fast energy release rates that are insensitive to unintended initiation while demonstrating the potential of sol–gel-derived aerogels in terms of versatility, tailored properties, and compatibility. The findings provide insightful conclusions on the influence of factors such as secondary oxidizers (KClO3) and dispersants (n-hexane and acetone) on the reaction kinetics and the sensitivity, playing crucial roles in determining reactivity and combustion performance. In tandem, ignition systems contribute significantly in terms of a high degree of reliability and speed. However, the advantages of using nano-thermites combined with hot bridge-wire systems in terms of ignition and combustion efficiency for potential, practical applications are not well-documented in the literature. Thus, this research also highlights the practicality along with safety and simplicity of use, making nano-Al/Fe2O3-KClO3 in combination with hot bridge-wire ignition a suitable choice for experimental purposes and beyond. [ABSTRACT FROM AUTHOR]

Mixed-oxide transition-metal aerogels (AGLs), particularly manganese-based AGLs, have attracted considerable interest over the past decade owing to their extraordinary properties, including high porosity, good surface area, and ultralow density. To develop easy and lightweight materials for the ever-increasing energy storage demands of the near future, we designed a novel Mn-based electrode material to meet these rising requirements. MnO/Mn2O3 AGLs were synthesized using a novel borohydride hydrolysis method and then annealed at 200, 400, and 550 °C. The as-synthesized AGLs yielded flower-like network structures, but their porosity increased with increasing temperatures, to a high temperature of 400 °C. This increased porosity and network structure facilitate a high capacitance. A supercapacitor (SC) constructed with the three-electrode material yielded 230 F/g for the MnAGL@400 sample, followed by yields from the MnAGL@200 and MnAGL@550 electrodes. Furthermore, the device constructed with MnAGL@400 exhibited an energy density of 9.8 Wh/kg and a power density of ~16,500 W/kg at a current density of 20 A/g. The real-time applicability of the AGL was demonstrated by engineering a two-electrode device employing MnAGL@400 as the positive electrode, which exhibited 97% capacity retention and 109% Coulombic efficiency over 20,000 cycles. [ABSTRACT FROM AUTHOR]

Aerogel composites reinforced by fibers have found extensive applications in the field of thermal insulation and energy conservation. However, the composites are hindered by their high infrared radiation transmittance and weak interface adhesion in practical applications. Herein, we designed and prepared a novel thin composite called 'fiber/whisker/aerogel paper' (SWAP) with a thickness of less than 1 mm. The SWAP integrated SiC nanowhiskers (SiC nw) as opacifiers and ultrafine SiO 2 fibers as reinforcement, fabricated through wet manufacturing and sol-gel process. The 'fiber/aerogel paper' (SAP) and SWAP exhibited low thermal conductivity at room temperature, measuring 0.025 W/(m·K) and 0.033 W/(m·K), respectively. Additionally, they exhibited low densities of 0.195 g/cm3 and 0.225 g/cm3, respectively. Notably, SWAP exhibited excellent high-temperature insulation performance, primarily due to its low infrared transmittance (50% at 3 μm). The incorporation of SiC nw and ultrafine SiO 2 fibers collectively enhanced the interfacial adhesion with the aerogel matrix even amidst rigorous testing (weight loss less than 3%). SWAP also demonstrated flexibility, high thermal stability, hydrophobicity, and flame resistance. Furthermore, a comprehensive investigation into the performance variations and influencing g factors of the material was conducted under different heat treatment conditions. This research provides guidance for the application of such materials under high temperatures. [ABSTRACT FROM AUTHOR]

In this study, novel tetradecylamine/MXene/cellulose nanocrystal composite phase change materials (TDA/MXene/CNC CPCMs) were prepared using a vacuum impregnation method. For the first time, lightweight MXene/CNC composite aerogel was employed as a support material in energy storage, with TDA serving as the phase change material. The latent heat of TDA/MXene/CNC CPCMs reached 221.5 J/g. Furthermore, the density of the MXene/CNC-2 composite aerogel was 0.0614 g/cm3, and its loading rate for TDA was as high as 90.6 wt%. Additionally, the thermal conductivity of TDA/MXene/CNC CPCM-5 was 0.491 W/(m·K), 1.87 times higher than that of pure TDA. The TDA/MXene/CNC CPCMs exhibited exceptional thermal stability up to 120 °C and maintained excellent shape stability at 60 °C. The composites exhibit a superior solar-thermal conversion ability with the conversion efficiency as high as 94.1%, The incorporation of MXene significantly enhances the photothermal conversion capability, providing an important avenue for the high-efficiency utilisation of solar energy. [ABSTRACT FROM AUTHOR]

Polymer templates are critical in the preparation of ceramic fibers from precursor solutions, but the available options are limited. Here, ZrO 2 nanofiber films and aerogels are developed by solution blow spinning method using hydroxypropyl methylcellulose (HPMC) and polyvinylpyrrolidone (PVP) as templates. The effects of HPMC ratio, polymer concentration, and calcination temperature on the morphology and structure of the ZrO 2 nanofibers are investigated. The nanofiber films with an areal density of 20 mg cm−2 exhibit excellent filtration property, achieving a filtration efficiency of 94.94% and a pressure drop of 136 Pa at an airflow velocity of 32 L min−1. The nanofiber aerogels display low density of 50 mg cm−3, low thermal conductivity of 0.039 W m−1 K−1, as well as superior compressibility, demonstrating significant potential for thermal protection applications. This work expands the formation template option of ceramic fibers, offering significant guidance in the development of flexible, high-temperature-resistant ceramic fiber materials. [ABSTRACT FROM AUTHOR]

The potential of aerogels as catalysts for the synthesis of a relevant class of bis-heterocyclic compounds such as bis(indolyl)methanes was investigated. In particular, the studied catalyst was a nanocomposite aerogel based on nanocrystalline nickel ferrite (NiFe2O4) dispersed on amorphous porous silica aerogel obtained by two-step sol–gel synthesis followed by gel drying under supercritical conditions and calcination treatments. It was found that the NiFe2O4/SiO2 aerogel is an active catalyst for the selected reaction, enabling high conversions at room temperature, and it proved to be active for three repeated runs. The catalytic activity can be ascribed to both the textural and acidic features of the silica matrix and of the nanocrystalline ferrite. In addition, ferrite nanocrystals provide functionality for magnetic recovery of the catalyst from the crude mixture, enabling time-effective separation from the reaction environment. Evidence of the retention of species involved in the reaction into the catalyst is also pointed out, likely due to the porosity of the aerogel together with the affinity of some species towards the silica matrix. Our work contributes to the study of aerogels as catalysts for organic reactions by demonstrating their potential as well as limitations for the room-temperature synthesis of bis(indolyl)methanes. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide (MoS2) is a promising alternative to graphite anodes in battery materials. Therefore, it is critical to scrutinize their structural stability and charge storage capacity during battery operation. Herein, freestanding electrodes consisting of MoS2‐incorporated carbon nanotube aerogels are fabricated using a simple yet scalable hydrothermal method, as used in lithium‐ion batteries. The outer nitrogen‐doped graphitic carbon (NGr) layers support efficient charge transport, even under a substantial compressive environment, and improve the structural integrity, showing significant improvements in battery performance, such as a high rate capacity of 820 mAh g−1 at the current density of 5 A g−1 and 94% capacity retention after 170 cycles (1170 mAh g−1 at 1 A g−1 after 170 cycles), even in the absence of polymer binders and conductive additives. The resulting NGr/MoS2/single‐walled carbon nanotubes freestanding electrodes have great potential to increase the volumetric and gravimetric energy density of batteries. [ABSTRACT FROM AUTHOR]

A practical carbon dioxide (CO2) conversion and utilization system shows great potential for ameliorating the greenhouse effect. Herein, an integrated carbon aerogel-based photothermal catalysis microreactor with photothermal conversion, enhanced mass transfer adsorption and a thermal catalytic reactor is designed. As a solar-powered CO2 utilization module, this microreactor can conveniently convert CO2 into economically valuable products without elaborate equipment and operation processes. [ABSTRACT FROM AUTHOR]

Aqueous zinc ion batteries have the advantages of low cost, high safety, high theoretical specific capacity. However, the charging and discharging process is usually accompanied by side reactions such as dendrite growth, hydrogenolysis, corrosion of electrodes, passivation, etc. which limits the development and application. In this work, the zinc anode is modified by constructing a silica aerogel layer with ultra‐high specific surface area and abundant polar functional groups (−OH, −COOH, −CH3), which not only provides abundant active sites for the uniform deposition of zinc ions, but also construct an artificial protective layer that acting as a desolvation layer and a zinc ion flux regulator. Consequently, the altered zinc anode exhibits an extremely durable zincophilic characteristic and a declining interfacial impedance. The constructed artificial layer can prevent side reactions and promote uniform zinc ion deposition to prevent the generation of zinc dendrites during the charge/discharge process. Results show that the symmetric cells composed of modified Zn anodes can be stably cycled for more than 1100 h at 0.5 mA cm−2 and 0.5 mAh cm−2, which is much higher than that of bare Zn. In addition, the life and capacity retention of the Zn/MnO2 full cells were also significantly improved. [ABSTRACT FROM AUTHOR]

Interfacial jamming and assembly, facilitated by nanoparticle surfactant (NPS) complexation, demonstrate a remarkable efficacy in stabilizing multiphase systems, evident in structured liquid streams and structured Pickering emulsions. However, the utilization of structured liquid templates to tune multiple porosity levels of ultra‐flyweight aerogels is barely discussed. In this study, a structured Pickering emulsion is prepared through mixing an aqueous dispersion of graphene oxide (GO) with an organic (hexane) solution containing an active ligand. The emulsion is jetted into the same organic phase, resulting in “dual jamming”. This process produced worm‐like aerogels with porosity that can be precisely tailored at four different levels: i) voids between filaments, ii) cavities produced by evaporation of trapped hexane droplets, iii) pores generated from sublimation of water in the bulk of GO emulsion, and iv) microscopic regions trapped between GO flakes or fractures/holes within GO nanosheets. These aerogels exhibit ultra‐low density (1.67–2.3 mg cm−3), high compressibility, and shape recovery. The multi‐scale porosity, created by structural design, endows aerogels with a record‐level fluid sorption capacity (e.g., 615 g g−1 for chloroform). Additionally, the aerogels demonstrate an absorption‐dominant electromagnetic interference (EMI) shielding mechanism, achieving a remarkable specific EMI shielding (SSE/t) of 67 178 dB cm2 g−1. [ABSTRACT FROM AUTHOR]

Developing energy harvesting devices is crucial to mitigate the dependence on conventional and rigid batteries in wearable electronics, ensuring their autonomous operation. Nanogenerators offer a cost‐effective solution for enabling continuous operation of wearable electronics. Herein, this study proposes a novel strategy that combines freeze‐casting, freeze‐drying, and printing technologies to fabricate a fully printed triboelectric nanogenerator (TENG) based on polyvinylidene fluorid‐etrifluoroethylene P(VDF‐TrFE) porous aerogel. First, the effects of porosity and poling on the stretchability and energy harvesting capabilities of P(VDF‐TrFE) are investigated, conducting a comprehensive analysis of this porous structure's impact on the mechanical, ferroelectric, and triboelectric properties compared to solid P(VDF‐TrFE) films. The results demonstrate that structural modification of P(VDF‐TrFE) significantly enhances stretchability increasing it from 7.7% (solid) to 66.4% (porous). This modification enhances output voltage by 66% and generated charges by 48% for non‐poled P(VDF‐TrFE) porous aerogel films compared to their non‐poled solid counterparts. Then, a fully printed TENG is demonstrated using stretchable materials, exhibiting a peak power of 62.8 mW m−2 and an average power of 9.9 mW m−2 over 100 tapping cycles at 0.75 Hz. It can illuminate light‐emitting diodes (LEDs) through the harvesting of mechanical energy from human motion. This study provides a significant advance in the development of energy harvesting devices. [ABSTRACT FROM AUTHOR]

Fueled by the concepts of topological insulators, analogous topological acoustics offer an alternative approach to manipulate sound. Theoretical proposals for subwavelength acoustic topological insulators are considered to be ideal effective parameters or utilizeing artificial coiling-space metamaterials. However, the corresponding realization using realistic soft metamaterials remains challenging. In this study, we present the design of an acoustic subwavelength second-order topological insulator using nanoscale porous solid material, silica aerogel, which supports pseudospin-dependent topological edge and corner states simultaneously. Through simulations and experiments, we demonstrate that silica aerogel can function as a soft acoustic metamaterial at the subwavelength scale. By embedding silica aerogel in an air matrix to construct a honeycomb lattice, a double Dirac cone is obtained. A topological phase transition is induced by expanding or contracting the supercell, resulting in band inversion. Additionally, we propose topologically robust acoustic transmission along the one-dimensional edge. Furthermore, we discover that the proposed sonic crystal sustains zero-dimensional corner states, which can efficiently confine energy at subwavelength corners. These findings offer potential for the realization of subwavelength topological acoustic devices using realistic soft metamaterials. [ABSTRACT FROM AUTHOR]

Developing high-performance and low-cost protein purification materials is of great importance to meet the demands for highly purified proteins in biotechnological industries. Herein, a facile strategy was developed to design and construct high-efficiency protein absorption and separation media by combining aerogels' molding techniques and impregnation processes. Poly (ethylene-co-vinyl alcohol) (EVOH) nanofibrous aerogels (NFAs) were modified by grafting butane tetracarboxylic acid (BTCA) over them in situ. This modification was carried out using polyphosphoric acid as a catalyst. The resulting EVOH/BTCA NFAs exhibited favorable comprehensive properties. Benefiting from the highly interconnected porous structure, good underwater compressive properties, and abundant absorption ligands, the obtained EVOH/BTCA NFAs possessed a high static absorption capacity of 1082.13 mg/g to lysozyme and a short absorption equilibrium time of about 6 h. A high saturated dynamic absorption capacity for lysozyme (716.85 mg/g) was also realized solely by gravity. Furthermore, EVOH/BTCA NFAs displayed excellent reusability, good acid and alkaline resistance, and unique absorption selectivity performance. The successful synthesis of such aerogels can provide a potential candidate for next-generation protein absorbents for bio-separation and purification engineering. [ABSTRACT FROM AUTHOR]

Cellulose-based aerogel has attracted considerable attention for its excellent adsorption capacity, biodegradability, and renewability. However, it is considered eco-unfriendly due to defibrillation of agriculture waste and requires harmful/expensive chemical agents. In this study, cornstalk rind-based aerogel was obtained via the following steps: green H2O2/HAc delignification of cornstalk rind to obtain cellulose fibers, binding with carboxymethyl cellulose (CMC)/polyvinyl alcohol (PVA) and freeze-drying treatment, and hydrophobic modification with stearic acid. The obtained aerogel showed high compressive strength (200 KPa), which is apparently higher (about 32 kPa) than NaClO-delignified cornstalk-based cellulose/PVA aerogel. Characterization of the obtained aerogel through SEM, water contact angle, etc., showed high porosity (95%), low density (0.0198 g/cm−3), and hydrophobicity (water contact angle, 159°), resulting in excellent n-hexane adsorption capacity (35 g/g), higher (about 29.5 g/g) than NaClO-delignified cornstalk-based cellulose/PVA aerogel. The adsorbed oil was recovered by the extrusion method, and the aerogel showed excellent recyclability in oil adsorption. [ABSTRACT FROM AUTHOR]