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Herein, considering the great potential of nitrogen-doped hierarchical porous carbons in energy storage and CO 2 capture, we designed a convenient and easily large-scale production strategy for preparing nitrogen-doped hierarchical porous carbon sphere (NHPCS) materials. In this synthesis route, spherical resorcinol-formaldehyde (RF) resins were selected as carbon precursor, and then the ZnCl 2 -impregnated RF resin spheres were carbonized in a NH 3 atmosphere at a temperature range of 600–800 °C. During the one-step heat-treatment process, nitrogen atom could be efficiently incorporated into the carbon skeleton, and the interconnected and hierarchical pore structure with different micro/mesopore proportion could be generated and tuned by adjusting the activating agent ZnCl 2 dosage and carbonization temperature. The resultant nitrogen-doped hierarchical porous carbon sphere materials exhibited a satisfactory charge storage capacity, and the optimal sample of NHPCS-2-8 with a high mesopore proportion obtained at 800 °C with a ZnCl 2 /RF mass ratio of 2:1 presented a specific capacitance of 273.8 F g −1 at a current density of 0.5 A g −1 . More importantly, the assembled NHPCS-2-8-based symmetric capacitor displayed a high energy density of 17.2 Wh kg −1 at a power density of 178.9 W kg −1 within a voltage window of 0 ∼ 1.8 V in 0.5 M Na 2 SO 4 aqueous electrolyte. In addition, the CO 2 capture application of these NHPCS materials was also explored, and the optimal sample of NHPCS-0-8 with a large micropore proportion prepared at 800 °C exhibited an exceptional CO 2 uptake capacity at ambient pressures of up to 4.23 mmol g −1 at 0 °C. [ABSTRACT FROM AUTHOR]

CO 2 capture, storage and utilization (CCSU) is the most promising strategy for ameliorating the ever-increasing atmospheric CO 2 concentrations problem. The development of advanced porous solid adsorbents for efficient CCSU is a burgeoning interest in materials science. Currently, porous carbon-based adsorbents face the major challenge of balancing the structural features of porosity and surface chemistry for CCSU in a durable and scalable material. To this end, we designed hierarchically porous carbons with tailorable porosity and adjustable surface chemistry, and clarify the influence of porosity and surface chemistry on CO 2 capture. Meanwhile, the systematic study revealed the synergetic effect of microporosity of less than 10 Å and surface chemistry on CO 2 capture, and the synergistic effect mechanism of various surface groups on CO 2 capture property was also ascertained in detail. Porosity was found to be the determinant role on CO 2 capture, in particular the microporosity of < 10 Å and ultramicroporosity of < 7.0 Å. While, surface chemistry played a significant role on the improvement of CO 2 capture, especially the CO 2 /N 2 selectivity at higher temperature. Importantly, this work provided an instructive guideline for rational design of high-efficient porous carbon CO 2 adsorbents with a balanced porosity and surface chemistry property. ● Hierarchically porous carbon with tailorable porosity and surface chemistry was obtained. ● The effect of porosity and surface chemistry on CO 2 capture was clarified. ● The synergistic effect mechanism of various surface groups was ascertained. ● An instructive guideline for rational design of porous carbon adsorbents was provided. [ABSTRACT FROM AUTHOR]

While the fundamental trade-off in leaf traits related to carbon capture as described by the leaf economics spectrum is well-established among plant species, the relationship of the leaf economics spectrum to stem hydraulics is much less known. Since carbon capture and transpiration are coupled, a close connection between leaf traits and stem hydraulics should be expected. We thus asked whether xylem traits that describe drought tolerance and vulnerability to cavitation are linked to particular leaf traits. We assessed xylem vulnerability, using the pressure sleeve technique, and anatomical xylem characteristics in 39 subtropical tree species grown under common garden conditions in the BEF-China experiment and tested for correlations with traits related to the leaf economics spectrum as well as to stomatal control, including maximum stomatal conductance, vapor pressure deficit at maximum stomatal conductance and vapor pressure deficit at which stomatal conductance is down-regulated. Our results revealed that specific xylem hydraulic conductivity and cavitation resistance were closely linked to traits represented in the leaf economic spectrum, in particular to leaf nitrogen concentration, as well as to log leaf area and leaf carbon to nitrogen ratio but not to any parameter of stomatal conductance. The study highlights the potential use of well-known leaf traits from the leaf economics spectrum to predict plant species' drought resistance. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Poplar catkins-derived N-doped hierarchical porous carbon microtubes were obtained. • Our facile approach represents an example of trash-to-treasure transformation. • The porosity, surface structure, tube wall thickness can be tailored. • The optimal porous carbon microtube sample shows a satisfactory CO 2 uptake. • It also exhibits an excellent CO 2 /N 2 adsorption selectivity and recyclability. Abstract Poplar catkins are an environmental pollutant because they can trigger sneezing, shortness of breath, skin allergy and even cause forest fire. It is very attractive to discover ways for reducing the threats of poplar catkins to the environment and human health and even to convert poplar catkins into useful materials. Herein we report on a facile and cost-efficient strategy for the synthesis of hierarchical porous carbon microtubes using poplar catkins as the carbon source. The synthesis involves pre-carbonization and subsequent ZnCl 2 activation. The resultant materials not only inherit the natural tubular morphology of poplar catkins, but also develop a hierarchical porous structure, with nitrogen from the biomass being self-doped in the resultant carbon skeleton. The hierarchical porosity, especially the microporosity with the pore size from 0.5 to 1 nm, surface structure, tube wall thickness and nitrogen content can be readily controlled by adjusting the activation temperature and the ZnCl 2 -to-precursor mass ratio. The produced materials exhibit an excellent CO 2 capture capacity. The optimal sample activated at 800 °C with a ZnCl 2 -to-precursor mass ratio of 4:1 shows an extraordinarily high CO 2 adsorption capacity of 6.22 and 4.05 mmol g−1 at 273 and 298 K, respectively, at 1 bar of CO 2. Furthermore, the material also displays an excellent recyclability and CO 2 /N 2 selectivity. Our approach not only relieves the environmental pollution of poplar catkins but also leads to the production of a high-performance CO 2 adsorbent, which is promising for industrial CO 2 capture and separation. It therefore demonstrates an example of trash-to-treasure transformation. [ABSTRACT FROM AUTHOR]