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The cost of CO2 separation and energy consumption can be decreased through the use of CO2 adsorption. Due to the electron-rich heteroatoms in its network, polyimide (PI) has a remarkable affinity for CO2. Polyethylene glycol (PEG) can increase the layer spacing of polymers, so as to change the mass transfer of CO2 in it. Furthermore, the ether bond (-O-) in PEG has good affinity for CO2. In this study, PEG-1000 was introduced into PI aerogel by mild sol-gel method at low temperature, and freeze-drying was used to produce PI/PEG composite aerogels with directional pore structure. The effect of PEG-1000 content and directional pore structure of the PI/PEG composite aerogels on CO2 adsorption performance were further studied. The L-PI/PEG-4 composite aerogel, which contains 4 g PEG and is directionally frozen in liquid nitrogen, has a CO2 adsorption capacity of 16.76 cm3/g at 25°C and 1 bar. L-PI/PEG-4 aerogel also exhibits high CO2/N2 selectivity and adsorption cycle stability. [ABSTRACT FROM AUTHOR]

Developing highly efficient and stable photocatalysts is an effective method to achieve CO2 photocatalytic reduction. Herein, PI/WO3 aerogel photocatalyst was prepared by chemical amide reaction coupled with an ethanol supercritical drying technique. The novel aerogel photocatalysts exhibit excellent photocatalytic performance for reducing CO2 into CO. In particular, PI/WO3-10 aerogel photocatalyst shows the highest yield of CO (5.72 μmol g–1 h–1), which is ca 11-fold higher than that of the pristine PI aerogel. The high CO2 reduction activity can be attributed to the Z-scheme structure, which enhances the separation of photo-generated electron – holes, and induces H2O oxidation on WO3 nanosheets and CO2 reduction on PI aerogel. The photocatalytic reaction mechanism of CO2 when using PI/WO3 aerogel photocatalyst is proposed. [ABSTRACT FROM AUTHOR]

A novel bifunctional Ag@AgSCN nanostructure with excellent photocatalytic degradation and antimicrobial performance has been successfully prepared by a simple precipitation method. Both the presence of PVP and the dropping rate of AgNO3 solution have a great effect on the triangle-shaped Ag@AgSCN nanostructure with exposed {−112} facets. The degradation constant (k) of triangle-shaped Ag@AgSCN (0.28 min−1) is three times as much as that of Ag@AgSCN nanoparticles (0.09 min−1), and also shows better bactericidal activity than Ag@AgSCN nanoparticles. Furthermore, the triangle-shaped Ag@AgSCN exhibits excellent structure stability in the cycling experiments, and reaches six cycles and four cycles in the photocatalytic degradation and antimicrobial experiments, respectively. The novel triangle-shaped Ag@AgSCN structure provided high-index facets with high catalytic activity, increased the adsorption amount of phenol and improved the separation efficiency of the electron–hole pairs, which resulted in more active species being produced over triangle-shaped Ag@AgSCN than Ag@AgSCN nanoparticles. The effect of the active species on the photocatalytic activity is in the order: ṖO2− radicals ＞ h+ ＞ ṖOH radicals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Porous polyimide/carbon quantum dots (CQDs) aerogel was prepared successfully. • CQDs increased light absorption and adjusted band structure of aerogel. • The aerogel possessed large specific surface area and wide visible absorption range. • The aerogel had high photocatalytic activity under visible light. • h+ and ·O 2 – were the main active species to degrade the pollutant. Polyimide was widely studied as semiconductor polymer photocatalyst. However, polyimide photocatalyst suffers from small specific surface area, poor visible light absorption and low charge thansfer efficiency. Herein, porous polyimide/carbon quantum dots aerogel was prepared successfully via supercritical CO 2 drying method. The carbon quantum dots were obtained by a green hydrothermal method. The carbon quantum dots could be anchored intimately on the polyimide aerogel by π -π stacking interactions. The polyimide/carbon quantum dots aerogel had large specific surface area and porous structure. The carbon quantum dots increased the visible light absorption, adjusted the band structure of the polyimide aerogel and facilitated the generation and separation of photogenerated electron and holes. Thus the photocatalytic property of the polyimide/carbon quantum dots aerogel was increased compared to pure polyimide aerogel. h+ and ·O 2 – were the main active species to degrade the pollutant. Finally, the mechanism of the photocatalysis under the visible light was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mesoporous and flexible PI aerogel membrane is first selected as a PMS activator. • PI/PMS aerogel can efficiently remove AO7 without adsorption–desorption equilibrium. • PI/PMS aerogel membrane could keep high removal rate and permeation flux. • Non-radical pathway plays the dominant role for AO7 degradation. Driven by the organic contaminants in wastewater, peroxymonosulfate (PMS) as a source of reactive species has been developed, and metal-free catalysts have proven to be one kind of most promising PMS activators. In this work, mesoporous and flexible polyimide (PI) aerogel membrane with high specific surface area, expanded π-conjugated system and high strength is selected as one kind of PMS activator, and the PI/PMS aerogel system shows high organic contaminants degradation performance. Interestingly, the acid orange 7 (AO7) degradation rate constant of PI/PMS aerogel system without adsorption–desorption equilibrium stage is 2.5-fold faster than that of catalyst with adsorption–desorption equilibrium stage, because the adsorption of AO7 on PI aerogel covers the active sites of PI, and little PMS can be activated on the surface of PI aerogel. Notably, PI/PMS membrane system could remove 96.21% of AO7 with a slight decreased permeation flux for the twelfth cycle. Furthermore, the possible degradation mechanism was proposed, and radical quenching tests certified non-radical pathway played the dominant role for AO7 degradation. The successful application of PI aerogel membrane as PMS activator may shed light on designing new types of aerogel membrane for wastewater treatment. [ABSTRACT FROM AUTHOR]

Carbon aerogel (CA) based materials have multiple advantages, including high porosity, tunable molecular structures, and environmental compatibility. Increasing interest, which has focused on CAs as electrocatalysts for sustainable applications including oxygen reduction reaction (ORR), oxygen evolution reaction (OER), hydrogen evolution reaction (HER), and CO2 reduction reaction (CO2RR) has recently been raised. However, a systematic review covering the most recent progress to boost CA-based electrocatalysts for ORR/OER/HER/CO2RR is now absent. To eliminate the gap, this critical review provides a timely and comprehensive summarization of the applications, synthesis methods, and principles. Furthermore, prospects for emerging synthesis, screening, and construction methods are outlined. [ABSTRACT FROM AUTHOR]

• PI/Ag aerogel photocatalysts were designed by the sol-gel method and ethanol supercritical drying technique, which can induce the formation of Ag C bonds and Ag nanoparticles in PI/Ag aerogels. • The average rate of H 2 production is 166.1 μmol h−1 g−1 for PI/Ag-1 aerogel, which is ca. 8 times as much as that of PI aerogel. • Photocatalytic activity for H 2 production over PI/Ag aerogel is improved much due to the enhanced carrier mobility efficiency, optical absorption and large specific area of the photocatalyst. As one kind of promising photocatalyst, polyimide (PI) still suffers from poor light absorption, low charge transfer efficiency and small specific surface area. Herein, PI/Ag aerogel photocatalysts were designed by the sol-gel method and ethanol supercritical drying technique. As expected, Ag element in PI/Ag aerogel is in two forms, one is introduced into the imide ring of PI in the form of Ag C bond, and another is the dopant Ag atoms. The former kind of Ag element can weaken the planar hydrogen bonding and improve the charge transfer efficiency, and the latter can form LSPR effect and promote the photoelectron-holes separation. Apart from that, the high specific surface area of the aerogel photocatalyst also favors the photocatalysis. All these effects boost the photocatalytic activity of the PI/Ag aerogel photocatalysts. The average rate of H 2 production is up to 166.1 μmol h−1 g−1 for PI/Ag-1 aerogel, which is ca. 8 times as much as that of PI aerogel. The work supplies an efficient approach for constructing effective aerogel photocatalysts for H 2 production. [ABSTRACT FROM AUTHOR]

Hydrogen is regarded as one of the most promising energy sources of the future, due to its low-cost, zero-pollution, and high-heat value. Nevertheless, traditional methods of storing hydrogen are commonly accompanied by the risk of leaks and explosions, so how to store and transport hydrogen safely and efficiently is a critical issue that needs to be addressed. Solid-state hydrogen storage is the most attractive way to store hydrogen in nanomaterials by chemical or physical adsorption, which has the advantages of high energy density and good safety. Here, a rational Ni–Zn bimetallic MOF has been constructed by a straightforward synthetic technique, in which the Zn atom was partially replaced by the Ni atom. The micropore rate of the Ni–Zn bimetallic MOFs is higher than that of ZIF-8. In addition, the presence of Ni provides more unsaturated metal sites and strengthens the bonding between hydrogen molecules and Ni, effectively improving the hydrogen storage capacity of Ni–Zn bimetallic MOFs. The experimental results show that the hydrogen adsorption capacity of Ni–Zn bimetallic MOFs can reach 1.35 wt% at 77 K and 1 bar. [ABSTRACT FROM AUTHOR]

The CO 2 electrochemical reduction reaction (CO 2 ERR) offers an effective way to solve the problems of energy storage fluctuation and CO 2 over-emission at the same time. However, the mass transfer limitation during CO 2 ERR owing to the gaseous property of CO 2 greatly restricts the efficiency and selectivity of CO 2 reduction. Here, we report, for the first time, the design of a copper-zinc (CuZn) bimetal decorated superstructure catalyst (CuZn@KCA) via capitalizing on porous N-doped konjac glucomannan (KGM) aerogel and CuZn metal organic frameworks (CuZn-MOF), based on multiphysics infinite elemental simulations. The CuZn@KCA catalysts show high performance for CO 2 ERR (faradaic efficiency for HCOOH reaches 75% at −1.0 V vs. RHE). As demonstrated by infinite elemental simulations and detailed characterizations, the improved CO 2 ERR is attributed to the mass transfer enhancement effect of the superstructure catalyst on the reaction process (The mass transfer with CuZn@KCA is 16 times higher than that with CuZn-MOF). As such, the strategy for crafting a hierarchical superstructure might open up an avenue to improve the reaction activity of CO 2 ERR. • CuZn@KCA superstructure catalyst is designed and fabricated through finite element simulations and ice-templated method. • CuZn@KCA exhibits prominent CO 2 ERR performance and excellent stability for long time operation. • Fast charge and mass transfer rates attributed to hierarchical superstructure lead to higher CO 2 conversion FE. [ABSTRACT FROM AUTHOR]

Pyrolysis-free metal–organic frameworks (MOFs) with optimized particle sizes were used as capacitive deionization (CDI) materials in oxygenated saline water. Upon decreasing the particle size of the MOFs, excellent cycling stability and higher CDI performance were achieved. This was possibly due to the improvement in charge transfer and electrolyte permeation, uncovering the significance of particle size control in improving CDI performance. [ABSTRACT FROM AUTHOR]

The polyimide is a promising semiconductor photocatalyst. However, its photocatalytic activity is poor because of its small specific surface area, low visible light absorption and easy recombination of photoexcited electron and hole. Herein, porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel with excellent photocatalytic performance is prepared via supercritical fluid drying technology. The material aerogel has large surface area and the structure is porous network. The carbon quantum dots increase the visible light absorption of the polyimide aerogel. The ZnS quantum dots change the VB edge, CB edge and band gap of the polyimide aerogel. Both carbon quantum dots and ZnS quantum dots could improve the charge transfer and facilitate the separation of photoexcited electron and hole. The visible-light photocatalytic performance over oxytetracycline of porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel is increased largely compared to pure polyimide aerogel. The photocatalytic degradation mechanism of the polyimide material aerogel is proposed. ·O 2 − and h+ play the key role in the photocatalytic degradation. This work supplies an effective method to prepare visible-light photocatalytic materials. [Display omitted] • Porous polyimide/carbon quantum dots/ZnS quantum dots material aerogel was synthesized successfully. • The aerogel possessed large specific surface area and wide visible absorption range. • The aerogel had excellent visible light photocatalytic activity. • The h+ and ·O 2 − played important roles to the photocatalytic degradation. [ABSTRACT FROM AUTHOR]

Bio-based polyimide (PI)/halloysite nanotube (HNT) nanocomposites based on 2,5-furandicarboxylic acid were prepared by in situ polymerization. The pristine HNTs were modified by tetraethoxysilane (TEOS) and 4,4′-oxybisbenzenamine (ODA). The bio-based PI/HNT nanocomposite film exhibited lower moisture absorption than pure bio-based polyimide, showing that the water resistance of the bio-based polyimide film was improved. The thermal stability and glass transition temperature (Tg) of PI/HNTs nanocomposites were improved with the addition of modified HNTs. Both the tensile strength and Young's modulus of bio-based PI/HNTs nanocomposite films were enhanced. A 37.7% increase in tensile strength and a 75.1% increase in Young's modulus of bio-based PI/HNTs nanocomposite films, with 1 wt% of the modified HNTs, were achieved. The result confirmed that 2,5-furandicarboxylic acid could replace the oil-based material effectively, thus reducing pollution and protecting the environment. Finally, a preparation mechanism to prepare bio-based PI/HNTs nanocomposite is proposed. [ABSTRACT FROM AUTHOR]

• Crack-free monolithic Al 2 O 3 Y 2 O 3 SiO 2 ternary aerogel was successfully synthesized by synchronous sol-gel method. • Al 2 O 3 Y 2 O 3 SiO 2 aerogel exhibited low density of 0.071 g/cm3 and high specific area up to 675.7 m²/g. • Mullite fiber reinforced Al 2 O 3 Y 2 O 3 SiO 2 aerogel showed excellent thermal insulation performance, the thermal conductivity at 1000 °C is only 0.079 W·m−1·K−1. Against the background of global energy shortages and the need for long-term flight safety of aerospace vehicles, traditional silica aerogels have the problems of insufficient temperature resistance and poor thermal insulation at high-temperatures, and are no longer able to meet the demand. In this study, a series of monolithic Al 2 O 3 Y 2 O 3 SiO 2 ternary aerogels were successfully synthesized via synchronous sol–gel and ethanol supercritical drying. Both the prepared aerogels and the calcined samples at 1000 °C exhibited a complete three-dimensional network structure and a high specific surface area (up to 675.7 m2/g and 214.4 m2/g), which was attributed to the supporting effect of the Al 2 O 3 component on the overall skeleton and the inhibiting effect of the Y 2 O 3 component on the crystal transformation. Mullite fiber reinforced Al 2 O 3 Y 2 O 3 SiO 2 aerogel composites were synthesized by vacuum impregnation using mullite fiber felt as a matrix. The prepared sample exhibit very low thermal conductivity (as low as 0.079 W⋅m−1·K−1 at 1000 °C). In summary, the good structural stability and high temperature thermal insulation performance make Al 2 O 3 Y 2 O 3 SiO 2 ternary aerogel have the potential of efficient service in more application scenarios. This study provides a product optimization reference idea for the thermal insulation material industry. [ABSTRACT FROM AUTHOR]

Low-cost urea formaldehyde resin (UF)/reactive halloysite nanotubes (HNTs) nanocomposite adhesive was prepared successfully via in situ polymerization. The HNTs were modified to improve its compatibility with polymer. The XRD and FTIR results showed that physical and chemical interaction between the HNTs and polymer resin influenced the structure of UF owing to the functional groups on the HNTs. It is found from SEM images that the modified HNTs could be dispersed uniformly in the resin and the nanocomposite particles were spherical. The performance experiment confirmed that thermal stability of nanocomposite increased largely, formaldehyde emission of UF wood adhesive reduced 62%, and water resistance of UF wood adhesive improved by 84%. Meanwhile, the content of HNTs on the nanocomposites could be up to 60 wt %. The mechanism of the nanocomposites based on the reactive HNTs was proposed. The approach of the preparation could supply an idea to prepare other polymer/clay nanocomposites. [ABSTRACT FROM AUTHOR]

Biomass aerogel is attractive in various applications due to their renewable, biodegradable and eco-friendly advantages. Herein, a novel beta molecular sieve/carboxymethyl cellulose/polyvinyl alcohol composite aerogel (beta/CP) is prepared by direct mixing and directional freeze-drying as an efficient gas adsorbent with hierarchical porosity. The beta molecular sieve is uniformly dispersed in the three-dimensional skeleton of the aerogel. By adjusting the loading mass of the beta molecular sieve to constitute a reasonable porosity and pore size distribution, the synergistic effect between pore structures of different scales improves the adsorption performance. The experiment results of beta/CP-4 show that the CH 4 adsorption capacity can reach 60.33 cm3/g at 298 K and 100 bar, which is almost the same as that of the pure beta molecular sieve (62.09 cm3/g). The strong interaction between the aerogel and it prevents the molecular sieve agglomeration, improves the pore utilization, and also reduces the cost of using molecular sieve adsorbent. The above results indicate that the composite has good potential for application in the field of CH 4 storage. [Display omitted] [ABSTRACT FROM AUTHOR]

• Ion transport channels were established within the energy-storage RFDI system using ion exchange resin. • The mechanism of the enhanced performance of RFDI was comprehensively explained by experiments and finite element analysis. • The desalination performance of RFDI was verified using actual brackish water samples. In this work, we proposed a concept of redox flow deionization (RFDI) by constructing ion transport channels using ion exchange resins into the redox flow desalination (RFD) cell, and achieved a remarkable reduction of 27.4% in energy consumption and an increase of 24.1% in electrical power output compared to the conventional RFD system at the feed concentration of 1000–5000 mg L−1. Finite element analysis results further revealed the mechanism of RFDI process indicating that the ion exchange resin reduced the cell resistance by forming ions transport channels, which consequently improved the performance of RFDI. As a proof-of-concept application, the RFDI was evaluated for desalination of brackish water, which exhibited a freshwater productivity of 3.85 to 7.79 L m−2 h−1 with energy consumption of 5.39 to 2.31 Wh L–1. What's more, further modification of the ion transport channels in the RFDI cell could result in even higher brackish water desalination and energy storage performance. The findings of this study have significant implications for addressing global freshwater scarcity and the development of more efficient and sustainable desalination technologies. [ABSTRACT FROM AUTHOR]

• ZIF-8 derived porous carbon is supported on carbon aerogels derived from chitosan. • The composite possesses hierarchical porous structure with moderate N contents. • The composite has an ultrahigh specific surface area of 3075.5 m2/g. • The composite yields a large specific capacitance and outstanding cycling stability. In this study, chitosan was used to prepare nitrogen-doped carbon aerogels (CAs) anchored by ZIF-8 derived porous carbon (ZIF-8-C) using a facile in-situ deposition method combined with subsequent carbonization. CAs possessing a 3D mesoporous structure with interlaced nanosheets can be used as the skeleton for growth of ZIF-8 derived microporous carbon. The coexistence of mesopores and micropores can not only create more channels for electrolyte ions accessing, but also can provide electrical-double-layer capacitance. The results of electrochemical performance revealed that the ZCCA composite electrode shows the large specific capacitance of 241.6 F/g at a current density of 0.5 A/g in 2.0 M KOH electrolyte and superior cycle performance (capacity retention of 90% after 5000 cycles). The improvement in the electrochemical properties is owed to its hierarchically porous structure, ultrahigh specific surface area and moderate nitrogen contents. The preparation method offers the smart design of CAs-supported MOF-derived material for high-performance energy storage applications. [ABSTRACT FROM AUTHOR]

• CO 2 was applied to purify alumina powders and manifested to be high efficiency. • Al 2 O 3 content after being CO 2 pretreated could reach up to 99.9410%. • γ-Al 2 O 3 (10 μm) could be converted to boehmite (50–100 nm) after hydrothermal treated. Ultrapure, nanosized alumina (Al 2 O 3) powders are highly required for high performance Al 2 O 3 ceramics. However, the synthesis of the powders via an efficient and low-cost way is still a challenge. In the present research, we treated commercial γ-Al 2 O 3 powders via hydrothermal treatment combined with CO 2 pretreatment technique. The effect of hydrothermal pressure on the crystal phase, particle size and purity of the treated powders were investigated. In addition, the effect of CO 2 pretreatment on the purification of the powders was discussed. Commercial γ-Al 2 O 3 powders are fully converted to boehmite (AlOOH, a derived form of Al 2 O 3) at a hydrothermal pressure of 3.5 MPa. The boehmite powders reduce to the minimum particle size of 50–100 nm after being hydrothermal treated at 3.5 MPa. CO 2 pretreatment has been found to be very efficient in the purification of the powders. The Al 2 O 3 content of the powders after being CO 2 pretreated at 1 MPa could reach up to 99.9410% which is much larger than that of commercial γ-Al 2 O 3 powders (99.5096%). The as-received ultrapure, nanosized boehmite powders are promised raw materials for high performance Al 2 O 3 ceramics. [ABSTRACT FROM AUTHOR]

Abstract Polyimide (PI) aerogel cross-liked through multi-walled carbon nanotube (MWCNT) has been successfully synthesized by gelation of chemically imidized polyimide in N -methylpyrrolidinone (NMP) solution, followed by ethanol supercritical drying. The as-prepared PI(MWCNT) aerogel photocatalyst with 1 wt% MWCNT content exhibited excellent photocatalytic activity for oxytetracycline (OTC) degradation with a rate constant of 0.144 min−1, which is 20.6 and 3.3 times as many as that of PI powder and pure PI aerogel, respectively. Characterizations by a series of techniques certified that the enhanced photocatalytic activity of PI(MWCNT)-1% aerogel photocatalyst originated from not only the large specific area and modified band gap, but also the enhanced charge transfer effect because MWCNT can interact with PI through the π-π stacking interaction. The photo-induced electrons can be captured and rapidly transferred by MWCNT, efficiently enhancing the separation efficiency of photo-induced electron-holes. Graphical abstract Unlabelled Image Highlights • PI aerogel cross-linked by MWCNT has been successfully prepared by gelation of chemically imidized polyimide, followed by ethanol supercritical drying technique. • The degradation rate constant of oxytetracycline over PI(MWCNT) aerogel is 20.6 and 3.3 times as many as that of PI powder and pure PI aerogel, respectively. • PI(MWCNT)-1% aerogel exhibites superior photocatalytic activity for oxytetracycline degradation due to the large specific surface area, modified band gap and synergistic effect of PI and MWCNT. [ABSTRACT FROM AUTHOR]

Abstract Ca 0.66 Ti 0.66 Nd 0.34 Al 0.34 O 3 (CTNA) ceramics were prepared by solid-state reaction method and their sintering behavior, microwave dielectric properties, and microstructure were investigated. CTNA ceramics were examined by Raman scattering to reveal the correlation of perovskite structure with the microwave properties. It found that the area of peak A 1g (O) stretch mode reflects the quality factor Q × f value in the perovskite materials. This concludes that the oxygen octahedron plays an important role of the material's microwave performance. Sintering temperature affected the unit cell volume and the lattice parameters of the CTNA ceramics, the grain size distribution, the Gibbs free energy, the thermal expansion coefficient (CTE), and the dielectric properties (ε r , Q × f , τ f). The samples sintered at 1500 °C displayed the best dielectric constant and Q × f , as 44.94 and 41922.22 GHz, respectively. Highlights • The CTNA ceramics were sintered at different temperatures were investigated. • The thermal analysis detailed description of the stages of sintering process. • The unit cell volume is affected by the sintering temperature was confirmed by XRD. • Raman to reveal the correlation of structure with the microwave properties. • Relationship between grain size, Gibbs free energy, CTE, and dielectric properties. [ABSTRACT FROM AUTHOR]

TiO2/SiO2-Based nanocomposites with highly porous structures have received increasing attention due to their excellent photocatalytic activity. In this work, a TiO2/SiO2/Ag ternary composite aerogel with enhanced visible-light photocatalytic activity has been successfully synthesized through a facile sol–gel method combined with a supercritical drying technique. The specific surface area and pore structure of TiO2/SiO2/Ag aerogel could be controlled by adjusting the Si content. The TiO2/SiO2/Ag aerogel with pore size of 9.2 nm achieved the maximum adsorption capacity of oxytetracycline. The presence of SiO2 in TiO2/SiO2/Ag improved the compression strength of the aerogel and thus achieved long-term stability in photocatalysis. Furthermore, the addition of Ag particles in TiO2/SiO2/Ag effectively decreased the recombination of photo-electrons and holes. The photocatalytic degradation rates of oxytetracycline over the TiO2/SiO2/Ag aerogel with a mole ratio of Ag : Si : Ti = 0.1 : 10 : 4 were 3.1 and 2.3 times those over P25 and a TiO2/SiO2 aerogel. The enhanced photocatalytic performance of the TiO2/SiO2/Ag aerogel is attributed to the large specific surface area, 3-D porous structure, high electrical conductivity and compression strength of this novel composite aerogel. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • In 1−x Zn x O y heterogeneous NFs with mixed phases of c- and rh-In 2 O 3 are fabricated. • Rh-In 2 O 3 phase improves electrical conductivity and optimizes interface interplay. • Phase compositions of rh-In 2 O 3 and c-In 2 O 3 can be controllably tuned. • Excellent performance is attributed to the phase composition and interfaces. Abstract Poor cyclability and rate performance are two key problems hindering the practical application of In 2 O 3 in high power lithium-ion batteries. Herein, we report a phase transition strategy to fabricate novel In 1−x Zn x O y heterogeneous nanofibers with mixed phases of cubic bixbyite-type In 2 O 3 and rhombohedral corundunm-type In 2 O 3 to enhance the lithium ion storage ability. The one-dimensional structure shortens the path for lithium ion diffusion and electron transfer, and accommodates the large volume changes upon cycling. The introduction of rhombohedral corundunm-type In 2 O 3 can favorably improve the electrical conductivity, provide more pathways for lithium ion diffusion, and optimize the interface interplay. The optimal In 0.5 Zn 0.5 O 1.25 heterogeneous nanofibers exhibit superior cyclic stability and outstanding high-rate performance, which can be ascribed to the synergistic effects of excellent electrical conductivity, more pathways for lithium ion diffusion, and the coupling effect of heterogeneous interface. This new phase-transition induced formation of heterostructure nanofibers is enlightening in design high performance electrode materials for lithium ion batteries. [ABSTRACT FROM AUTHOR]

A novel Z‐scheme polyimide (PI)/AgBr@Ag aerogel photocatalyst has been successfully synthesized by combining an in situ precipitation method and a supercritical drying method. The as‐prepared PI/AgBr@Ag‐50 (50 wt % AgBr@Ag in PI/AgBr@Ag) aerogel photocatalyst exhibited excellent photocatalytic activity for oxytetracycline degradation with a rate constant of 0.025 min−1, which was 6.9 and 2.6 times higher than that of the PI aerogel or the AgBr@Ag nanoparticles, respectively. More significantly, the PI/AgBr@Ag‐50 aerogel photocatalyst showed stable cycling, which could be attributed to the high mechanical strength and 3D network of the PI aerogel. The introduction of AgBr@Ag on PI with a heterojunction structure efficiently promoted the separation of electron–hole pairs by a Z‐scheme mechanism. The reduced metallic Ag nanoparticles were found to function as centers for the transfer of electrons from AgBr to PI. This work has revealed a new application for the aerogel PI/AgBr@Ag photocatalyst in environmental protection. Two is better than one: AgBr@Ag nanoparticles were uniformly dispersed on a polyimide (PI) aerogel, and the resultant Z‐scheme PI/AgBr@Ag composite aerogel exhibited excellent photocatalytic activity for oxytetracycline (OTC) degradation under visible light, which can be attributed to the synergy between the AgBr@Ag plasmonic photocatalyst and the PI semiconductor photocatalyst (see figure). [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Polyacetylacetonatozirconium (PAZ) was used as precursor to synthesize ZrO 2 aerogel. • PAZ-ZrO 2 aerogel performed a compressive strength of 0.23 MPa and 20 ~ 25% strain. • The SSA (PV) of PAZ-ZrO 2 aerogel was 236 m2/g (1.568 cm3/g) after 1000 °C heat-treatment. Abstract Polyacetylacetonatozirconium was used as the precursor to synthesize ZrO 2 aerogel (PAZ-ZrO 2). The physical properties of the aerogel were compared with those generated from zirconyl chloride (ZOC-ZrO 2) and zirconyl nitrate (ZON-ZrO 2). PAZ-ZrO 2 aerogel has higher compressive strength (0.12–0.23 MPa) with lower density (0.12 ± 0.005 g/cm3) as compared to ZOC-ZrO 2 and ZON-ZrO 2 aerogel, of which the mechanical strengths are in the range of 0.02–0.15 MPa and the density of 0.13–0.17 g/cm3. After being treated at 1000 °C, the surface area (pore volume) of ZOC-ZrO 2 , ZON-ZrO 2 and PAZ-ZrO 2 aerogel are 210 m2/g (1.299 cm3/g), 223 m2/g (0.444 cm3/g) and 236 m2/g (1.568 cm3/g) respectively. [ABSTRACT FROM AUTHOR]

In the study, cetyltrimethyl ammonium bromide (CTAB) has been found to have a significant effect on the grain size of zirconia (ZrO 2 ) polycrystalline fibers from a precursor of polyacetylacetonatozirconium (PAZ). A relation between the variation in the grain size of the fibers sintered at 1000 °C for 1 h and CTAB addition has been established by scanning electron microscopy (SEM) and matching the results by a Gaussian Function. The grain size increased firstly and then decreased at an elevated weight percent of CTAB with respect to PAZ. ZrO 2 nucleation at 500 °C and grain growth during thermal treatment between 500 and 1000 °C were investigated by thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The results indicate that the addition of CTAB accelerated the decomposition of PAZ. The enhanced decomposition promoted ZrO 2 nucleation and the removal of residual carbon. While excess CTAB resulted in the increase of residual carbon on grain surface. The general kinetics of the grain growth was evaluated by Arrhenius equation and the results did matched well with the variation in grain size. [ABSTRACT FROM AUTHOR]

Solar-driven interfacial evaporation is an emerging route for desalination and wastewater treatment with great potential to alleviate freshwater shortages. However, the current solar-driven interfacial evaporation systems generally suffer from complex design, poor customization and salt accumulation issues. Design and preparation of solar-driven interfacial evaporation systems with excellent comprehensive performance and capable of being mass-produced remains a great challenge. Herein, we demonstrate a novel electrospun nanofiber sponge for efficient and sustained solar-driven interfacial evaporation. The nanofibrous structure of its surface can promote the absorption of light, and its interconnected pore structure is conducive to the diffusion of water vapor, thereby improving the evaporation effect. Under 1 sun irradiation (1 kW·m−2), the nanofiber sponge interfacial evaporation system showed an outstanding water evaporation rate (1.57 kg·m−2·h−1) with 95.6 % evaporation efficiency. The hierarchical porous structure, super-hydrophilic properties and integrated design of evaporation and mass transfer make it have superior water transport capacity and excellent salt self-discharge performance. Simultaneously, the excellent strength, flexibility, and processability of the nanofiber sponge can realize the customized fabrication of solar interfacial evaporation systems. This work is expected to advance the development of solar-driven interfacial evaporation systems toward compact, independent and portable. • The solar evaporation efficiency of PPy@NFS-EPE can reach 95.5 %. • PPy@NFS with directional porous structure has excellent water transport capacity. • Integrated design of PPy@NFS-EPE ensures adequate water supply and salt discharge. • PPy@NFS with excellent strength, flexibility and processability can realize the customized fabrication of evaporator. [ABSTRACT FROM AUTHOR]

[Display omitted] • SAM aerogel is prepared by directional freeze-drying method. • Tuning carbonization temperature and activator ratio to optimize performance. • SAM-700-4 shows 3D interconnected structure with large specific surface area. • SAM-700-4 shows excellent specific capacitance of 441.80 F/g at 0.5 A/g. • SAM-700-4//SAM-700-4 all-solid-state supercapacitor exhibit high energy density. Hierarchical porous carbon shows great potential in the field of energy storage due to high porosity, large surface area, and excellent electrical conductivity. Here, we successfully fabricated carbon aerogel derived from sodium alginate/melamine composite (SAM) by directional freeze-drying combined with simple carbonization and activation process. The optimal SAM-700-4 possesses a high nitrogen (5.67 at.%) and oxygen (8.98 at.%) contents along with high specific surface area of 2577.62 m2/g and unique directional channel structure. Due to their synergistic effect, the SAM-700-4 electrode exhibits a high specific capacitance of 441.80 F/g at a current density of 0.5 A/g. Interestingly, the all-solid-state symmetric supercapacitor based on SAM-700-4//SAM-700-4 in PVA/SA/KOH gel electrolyte has a large energy density of 20.87 Wh/kg at a power density of 4000 W/kg and exhibits excellent cycling stability. It is believed that this N, O co-doped directional hierarchical porous carbon aerogel may show promising prospects as advanced energy storage materials. [ABSTRACT FROM AUTHOR]

Biomass aerogels are attractive in various applications owing to their inherent advantages of renewability, biodegradability and eco-friendly. Herein, a novel composite aerogel of konjac glucomannan (KGM)/TEMPO-oxidized cellulose nanofibers (TOCNF)@HKUST-1 (KTA@HKUST-1) is prepared through a facile vacuum impregnation method combined with the directional freeze-drying process, which using KGM and TOCNF as raw materials. The structural analyses disclose that the KTA@HKUST-1 has a hierarchical porosity, in which HKUST-1 can provide micropores for adsorption, while the meso -/macropores from KTA act as high-speed channels to improve diffusion and mass transfer rate to transport CO 2 components into the micropores of HKUST-1. The experiment results of KTA@HKUST-1-10 (KTA@H10) show that the CO 2 adsorption capacity can reach 3.50 mmol·g−1 at 1 bar and 298 K, and the adsorption capacity retention rate as high as 91.43% after 7 cycles. In addition, the CO 2 /N 2 adsorption selectivity of KTA@H10 can reach 18.42, which has an excellent potential for selective CO 2 adsorption. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Multi-walled carbon nanotubes grown on the carbon paper substrate are prepared by in situ growth in a chemical vapor deposition system. Co(OH)2 is deposited on carbon nanotubes/carbon paper by electrodeposition methods. SEM images show that the successful growth of nanometer-sized Co(OH)2 nanosheets on the surface of carbon nanotubes/carbon paper substrate. The electrodes of Co(OH)2/carbon nanotubes/carbon paper composite are investigated for their use in supercapacitors with cyclic voltammograms, chronopotentiometric measurements and electrochemical impedance spectroscopy. The composite electrode shows the largest specific capacitance of 1083Fg−1 at a current density of 0.83Ag−1 in 6M KOH electrolyte. Furthermore, this composite exhibits good cycling stability and lifetime. The implanted CNTs between carbon paper and Co(OH)2 act as a good conductive medium for electrodes in supercapacitors, and the interconnected nanosheets of the Co(OH)2 can facilitate the contact of the electrolyte with active materials, and thus increase the capacitance. [Copyright &y& Elsevier]

Abstract: Resorcinol–formaldehyde/alumina composite (RF/Al2O3) gels were initially prepared by using sol–gel techniques, and then dried to aerogels with supercritical fluid CO2. After thermal treatment in argon atmosphere, RF/Al2O3 aerogels were successfully converted to monolithic carbon/alumina composite (C/Al2O3) aerogels. The samples were characterized by BET, SEM, TEM and XRD, and the compressive strengths were measured. The experimental results showed that the C/Al2O3 aerogels exhibited an interpenetrating framework with high mesoporosity. The as-synthesized C/Al2O3 aerogels consisted of spherical carbon particles and alumina (fibrous or columnar), which had high BET surface area (576–831m2/g) and showed high compressive strength (5.4–9.1MPa) and Young’s modulus (286.95–476.71MPa). These novel C/Al2O3 aerogels could possibly be used as thermal isolates, catalysts and adsorbents. [Copyright &y& Elsevier]

Abstract: The Xicun kiln is a typical kiln for firing porcelains for export, including celadon, which imitates the products of the Yaozhou kilns. In this paper, 10 pieces of celadon from the Xicun kiln and 8 celadon samples from the Yaozhou kiln were analysed in situ non-destructively by energy dispersive X-ray fluorescence microprobe and optical microscopy. The results indicated that the body of the Xicun celadon contained less TFe2O3, Cr, Sr and Zr, and more K2O and Rb than that of the Yaozhou celadon. Also, the glaze of the Xicun celadon contained lower quantities of Sr and higher Rb; thus, these elements could be employed as relevant markers for the non-destructive discrimination of the provenance of Xicun celadon. In addition, the thicker glaze, the numerous bubbles, and the existence of the middle layer could be used as auxiliary indicators for a micro-structural distinction between samples from the Yaozhou kiln and those originating from Xicun. [Copyright &y& Elsevier]

The polyaniline was synthesized by the emulsion polymerization and the polyaniline/polyacrylic acid (PANI/PAA) composite films were prepared through a layer-by-layer method. The porous PAA layer was used as a template for the deposition of PANI, and finally the composite film showed a network structure with large surface area and high porosity. The facile process for preparation of PANI/PAA composite films was good for large-scale production and application. The electrochromic performance of the PANI/PAA composite film was investigated by means of cyclic voltammogram, chronoamperometry and transmittance measurements. The composite film showed three typical redox couples, and the response time for reduction and oxidation was 90 and 102 ms, respectively. The PANI/PAA films also exhibited remarkable electrochromism ability with a reversible color change from yellow to purple and a transmittance change from 68 to 27% at 550 nm. [ABSTRACT FROM AUTHOR]

• Cellulose derived carbon aerogel coated by PANI used as a scaffolding framework. • ZIF-8 derived porous carbon (ZC) is anchored into PCA carbon framework. • ZPCA carbon composite has a high specific surface area and large N contents. • ZPCA carbon composite yield a large specific capacitance of 388 F g−1 at 0.5 A g−1. • The symmetric device shows ultrahigh energy density in 1 M Et 4 NBF 4 /AN electrolyte. Cellulose derived carbon aerogel (CA) with unique three-dimensional network coated with polyaniline (PANI) on its surface is used as a scaffolding framework to anchor ZIF-8. The designed ZIF-8 derived porous carbon (ZC)/PANI@CA (ZPCA) hybrid carbon composite through a facile solution immersion chemical route and subsequent carbonization process is employed as electrode for supercapacitor, which has contributed a large specific surface area, a hierarchical porous structure and reasonable N content (up to 6.27 at.%). The synthesized ZPCA electrode achieves an outstanding capacitance of 388 F g−1 at 0.5 A g−1 as well as an excellent cycling performance. More inspiringly, the symmetric supercapacitor based ZPCA achieves a high energy density of 13.4 Wh kg−1 at a power density of 250 W kg−1 using 2 M KOH aqueous solution, and an ultrahigh energy density of 81.8 Wh kg−1 at a power density of 950 W kg−1 is realized using Et 4 NBF 4 /AN electrolyte. [ABSTRACT FROM AUTHOR]

• The carbon source is the puffball spore with natural hollow sphere structure. • N, S self-doped hollow-sphere porous carbon is obtained via direct carbonization/activation. • The NS-HPC-4 electrode offers a high specific capacitance of 285F/g at 0.5 A/g. • NS-HPC-4 based supercapacitor yields an energy density of 58.4 Wh/kg in Et 4 NBF 4 /AN electrolyte. A novel N, S self-doped hollow-sphere porous carbon is directly prepared from abundant biomass puffball spores via a simple carbonization and KOH activation process for the first time. The electrochemical properties and porous structure of these carbons are explored by adjusting the amount of KOH. It is found that the obtained N, S self-doped hollow-sphere porous carbon with a KOH to carbon mass ratio of 4 (NS-HPC-4) exhibits the largest specific surface area (1431 m2/g), a well-developed hierarchical porous structure and moderate N/S contents. As a result, the NS-HPC-4 electrode in the supercapacitor delivers a large specific capacitance of 285 F/g at 0.5 A/g in KOH electrolyte. Furthermore, the symmetric supercapacitor based on NS-HPC-4 exhibits an energy density of 10.9 Wh/kg at a power density of 400.4 W/kg in 2 M KOH aqueous electrolyte, and achieves a high energy density of 58.4 Wh/kg at a high power density of 876.0 W/kg in 1 M Et 4 NBF 4 /AN organic electrolyte. These excellent results confirm that puffball spores derived porous carbons are promising candidates to be used in high performance supercapacitors. [ABSTRACT FROM AUTHOR]

The rare earth lanthanum aerogel monolith with low chlorine ions were synthesized by a modified epoxide gelation method. The actual wt% of Cl could be reduced to as low as 0.371 wt%. • Rare earth lanthanum based (La-) aerogels were prepared by a modified epoxide gelation method. • The La-aerogels monoliths have low chlorine (0.371 wt%) and high specific surface area (74 m2/g). • The La-aerogels were well crystallized and the microstructures consisted of La(OH) 3 rods and La 2 O 2 CO 3 lamellae. Rare earth lanthanum based aerogels with reduced chlorine ions were produced by a modified sol–gel process. In the process, the La3+ precursor was designed to coordinate acetylacetone to form a La-complex. Ethanediamine was added in sol solution to form hydrochloride precipitates that were filtered in the following step. After supercritical drying, La-aerogel monoliths with lamella and rod microstructure were achieved. The Ion Chromatography showed that the chlorine within the aerogel synthesized by an optimized recipe reduced to as low as 0.371 wt%, in compared to the well-established method (3.909 wt%). The sol–gel mechanism was explored in detail. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries (LSBs) are considered as one of the most promising energy storage devices owing to the high theoretical specific capacity and high theoretical specific energy, as well as natural abundance of sulfur. However, the soluble lithium polysulfide intermediates (LPSs) in electrolyte cause undesirable shuttle effect, resulting in the loss of sulfur and poor cycling stability. Herein, a novel tungsten oxide-decorated N, S co-doped carbon nanofibers (WO 3 @NS-CNFs) functional interlayer is applied to restrain the shuttle effect and enhance the cycling performance of LSBs. On the one hand, the uniformly distributed WO 3 can provide strong chemical anchoring sites for binding the LPSs and enhance the redox reaction kinetics. On the other hand, the NS-CNFs can also serve as the polysulfide trappers and enhance the electronic conductivity of sulfur electrodes. Therefore, benefiting from the synergy effect of WO 3 and NS-CNFs, the LSBs exhibit excellent cycling performance with a high initial capacity of 1444 mA h g−1 and reversible capacity of 1080 mA h g−1 after 100 cycles at 0.2 C, and superior rate capability of 946 mA h g−1 at 2 C. Image 1 • A novel WO 3 @NS-CNFs interlayer is firstly applied as anchor of polysulfides. • Synergistic WO 3 @NS-CNFs can inhibit shuttle effect and enhance redox kinetics. • The LSBs with WO 3 @NS-CNFs interlayers show remarkable electrochemical performance. [ABSTRACT FROM AUTHOR]