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To reduce the environmental impact of CO 2 , CO 2 capture has become an area of research interest. Hierarchically porous materials have been certified as efficiency CO 2 capture adsorbents. This work is aimed to construct hierarchically porous carbon frameworks (CPI-TPUs) with enhanced CO 2 capture performance. CPI-TPUs are derived from polyimide (PI)/thermoplastic polyurethane (TPU) composite aerogels (PI-TPUs) with mesopores and macropores. Accordingly, the obtained CPI-TPU2 exhibits an improved CO 2 uptake capacity (2.21 mmol/g, 298 K) compared to the pure CPI and PI-TPUs due to the synergistic effect of hierarchically pores, higher specific area and electron-rich heteroatoms. Specially, CPI-TPUs with pore volume ratio of mesopores/macropores to total pores in a range of 6–21 show high CO 2 uptake performance. These CPI-TPUs with high CO 2 adsorption capacities and suitable isosteric adsorption heats (Q st) are promising CO 2 adsorbents. [Display omitted] • A new method to fabricate hierarchically porous carbon frameworks is described. • CPI-TPU2 exhibits an improved CO 2 uptake capacity of 2.21 mmol/g (298 K, 1.0 bar). • CPI-TPUs with a (V meso +V macro)/V tot value of 6–21 show high CO 2 uptake performance. • CPI-TPU2 with a Q st value of 43.2 kJ mol-1 is a promising CO 2 adsorbent. [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]

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]

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]

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]

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]

• 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]

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]