A polymer gel derived from resorcinol and formaldehyde can be prepared in around 5 min using lysine as polymerization catalyst and nitrogen source. After pyrolysis of this polymer gel, a new type of nitrogen‐containing carbon monolith was obtained (see figure), which exhibits the highest CO2‐adsorption capacity to date of up to 3.13 mmol g−1 at room temperature.

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This work aims to optimize the structural features of hierarchical porous carbon monolith (HCM) by incorporating the advantages of metal-organic frameworks (MOFs) (Cu₃(BTC)₂) to maximize the volumetric based CO₂ capture capability (CO₂ capacity in cm³ per cm³ adsorbent), which is seriously required for the practical application of CO₂ capture. The monolithic HCM was used as a matrix, in which Cu₃(BTC)₂ was in situ synthesized, to form HCM-Cu₃(BTC)₂ composites by a step-by-step impregnation and crystallization method. The resulted HCM-Cu₃(BTC)₂ composites, which retain the monolithic shape and exhibit unique hybrid structure features of both HCM and Cu₃(BTC)₂, show high CO₂ uptake of 22.7 cm³ cm⁻³ on a volumetric basis. This value is nearly as twice as the uptake of original HCM. The dynamic gas separation measurement of HCM-Cu₃(BTC)₂, using 16% (v/v) CO₂ in N₂ as feedstock, illustrates that CO₂ can be easily separated from N₂ under the ambient conditions and achieves a high separation factor for CO₂ over N₂, ranging from 67 to 100, reflecting a strongly competitive CO₂ adsorption by the composite. A facile CO₂ release can be realized by purging an argon flow through the fixed-bed adsorber at 25 °C, indicating the good regeneration ability.

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A new synthetic approach for the fabrication of microporous carbon materials (HCMs) by using discrete chelating zinc species as dynamic molecular porogens to create extra micropores that enhance their CO2-adsorption capacity and selectivity is reported. During the carbonization process, the evaporation of the in situ-formed Zn species would create additional nanochannels that contribute to the additional micropore volume for CO2 adsorption. The resultant HCMs show an increased number of micropores, with sizes in the range 0.7-1.0 nm and a high CO2 -adsorption capacity of 5.4 mmol g(-1) (23.8 wt%) at 273 K and 3.8 mmol g(-1) (16.7 wt%) at 298 K and 1 bar, which are superior to those of most carbon-based adsorbents with N-doping or high specific surface areas. Dynamic gas-separation measurements, by using 16% CO2 in N2 (v/v) as a feedstock, demonstrated that CO2 could be effectively separated from N2 under ambient conditions and shows a high separation factor (S(CO2)/N2=110) for CO2 over N2, thereby reflecting a strongly competitive CO2 -adsorption capacity. If the feedstock contained water vapor, the dynamic capacity of CO2 was almost identical to that measured under dry conditions, thus indicating that the carbon material had excellent tolerance to humidity. Easy CO2 release could be realized by purging an argon flow through the fixed-bed adsorber at 298 K, thus indicating good regeneration ability.

Abstract. The carbon (C) cycling in semiarid and arid areas remains largely unexplored, despite the wide distribution of drylands globally. Rehabilitation practices have been carried out in many desertified areas, but information on the C sequestration capacity of recovering vegetation is still largely lacking. Using the eddy-covariance technique, we measured the net ecosystem CO2 exchange (NEE) over a recovering shrub ecosystem in northwest China throughout 2012 in order to (1) quantify NEE and its components and to (2) examine the dependence of C fluxes on biophysical factors at multiple timescales. The annual budget showed a gross ecosystem productivity (GEP) of 456 g C m−2 yr−1 (with a 90% prediction interval of 449–463 g C m−2 yr−1) and an ecosystem respiration (Re) of 379 g C m−2 yr−1 (with a 90% prediction interval of 370–389 g C m−2 yr−1), resulting in a net C sink of 77 g C m−2 yr−1 (with a 90% prediction interval of 68–87 g C m−2 yr−1). The maximum daily NEE, GEP and Re were −4.7, 6.8 and 3.3 g C m−2 day−1, respectively. Both the maximum C assimilation rate (i.e., at the optimum light intensity) and the quantum yield varied over the growing season, being higher in summer and lower in spring and autumn. At the half-hourly scale, water deficit exerted a major control over daytime NEE, and interacted with other stresses (e.g., heat and photoinhibition) in constraining C fixation by the vegetation. Low soil moisture also reduced the temperature sensitivity of Re (Q10). At the synoptic scale, rain events triggered immediate pulses of C release from the ecosystem, followed by peaks of CO2 uptake 1–2 days later. Over the entire growing season, leaf area index accounted for 45 and 65% of the seasonal variation in NEE and GEP, respectively. There was a linear dependence of daily Re on GEP, with a slope of 0.34. These results highlight the role of abiotic stresses and their alleviation in regulating C cycling in the face of an increasing frequency and intensity of extreme climatic events.

Presently, flexible electromechanical sensors are of particular interest to next generation mobile applications. To enrich the flexible encapsulants, herein, a fully biobased film is developed by cross-linking soy protein isolate (SPI) with nanocross-linker, aldehydebearing, cellulose nanocrystals (CNC). Thanks to the enhanced interfacial interaction between SPI and CNC resulting from the Maillard reaction, the protein-rich phase becomes more homogeneous with smaller domain size. Compared with neat SPI film, the resultant composite films exhibit an obviously improved mechanical property and water resistance. In particular, the heat-sealing property of such films is well maintained, which guarantees their application as encapsulation layers to construct flexible electromechanical sensors. These results indicate that green composite films hold promising applications as universal encapsulation materials for integrating flexible movement-monitoring electronics.

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