Search

[Display omitted] • Ionic liquid Solution Process (ILSP) was employed to prepare ionic covalent organic frameworks. • Strong electrophilic ionic liquid cations have the ability to regulate the iodine adsorption activity of sulfonic sites in COF. • The adsorption kinetics k 80% of optimal COF-Bmim absorbent is 2.69 g·g−1·h−1, an increase of 400 %. • DFT studies reveal a positive correlation between the local polarity of adsorption sites and adsorption performance. The research on the adsorption and conversion of non-polar gases (carbon dioxide, hydrogen, iodine, etc.) has attracted global attention. Extensive work has revealed the intuitive impact of the heteroatom effect on the adsorption performance of covalent organic framework (COF) adsorbents for non-polar gases. However, more influencing factors must be studied to more precisely design and construct target-specific COF adsorbents. In this work, an underlying influencing factor, local polarity, is discovered, which is defined as the polarity of the functional moiety. Due to the substitution of strong electrophile, the electron cloud distribution of the COF framework is regulated, and the local polarity that better matches the adsorption of target electrophilic gas (iodine) has been observed. The local polarity of COF has been controlled through several strong electrophilic ionic liquids, dramatically improving adsorption performance. The saturated adsorption capacity increases from 1.5 to 5.2 g·g−1, and the adsorption kinetics index k 80% value increases from 0.51 to 2.69 g·g−1·h−1. The insight would support precise chemical regulation of target-specific COF in energy and environment science. [ABSTRACT FROM AUTHOR]

[Display omitted] • Metal-free ionic hydrogel PAOI B -PTC was well fabricated by physical crosslinking. • Rigid PTC4− acted both as a physical crosslinking agent and an auxiliary group. • PAOI B -PTC exhibited a high tensile strength of 7.34 MPa. • The maximum U(VI) adsorption capacity of PAOI B -PTC was as high as 1008.03 mg g−1. • High U(VI) selectivity was achieved by hydrogen bond and synergistic coordination. Uranium is one of the most important elements in the nuclear industry, and efficient extraction of uranium from the ocean is conducive to the sustainable development of nuclear energy. In this work, rigid perylene tetracarboxylate anion (PTC4−) was introduced by physical (non-covalent) crosslinking strategy to obtain metal-free ionic hydrogel PAOI B -PTC. PTC4− not only increased the rigid structure content of ionic hydrogel, but also formed dynamic macrocycle AO-PTC with amidoxime (AO) through hydrogen bonds. Unlike reported heterogeneous additives, PTC4− did not undergo inhomogeneity or shedding. Therefore, PAOI B -PTC exhibited high strength (7.34 MPa), excellent solvent resistance and salinity tolerance. A large number of hydrophilic groups and multistage pore structure endowed PAOI B -PTC with high hydrophilicity, which facilitated U(VI) mass transfer and led to rapid adsorption rates (88.6 mg g−1 h−1, c 0 = 250 ppm). Since the metal-free component enabled more adsorption sites to be utilized, the maximum adsorption capacity of PAOI B -PTC was as high as 1008.03 mg g−1, which exceeded most reported hydrogel-based uranium adsorbents. Experiments and DFT calculations proved that PAOI B -PTC possessed high adsorption selectivity through uranyl recognition via hydrogen bonding and synergistic coordination by supramolecular structure AO-PTC. The low-concentration uranium capture capability and excellent recycling performance demonstrated the practical application potential of PAOI B -PTC. This work provides an idea for the design of metal-free ionic hydrogels with high-strength, and the established PAOI B -PTC is expected to be a candidate material for enhanced uranium extraction from seawater. [ABSTRACT FROM AUTHOR]

[Display omitted] • Leaching of the valuable metals and utilizing carbon residue from spent lithium-ion batteries. • K 2 CO 3 impregnated carbon utilized as an adsorbent for indoor CO 2 capture. • An investigation of the reaction mechanism for CO 2 adsorption on supported K 2 CO 3 under humid condition. • At low CO 2 concentrations, the CO 2 adsorption capacity for K 2 CO 3 /carbon ranged from 5.1 to 7.3 wt% Recycling and reusing the carbon-residues (i.e., graphite), as well as recovering valuable metals by leaching from spent lithium-ion batteries, is environmentally and economically significant. In particular, since a large amount of spent lithium-ion batteries (LIBs) will be generated along with the rapid growth of electric vehicles (EVs), research on recycling carbon-residues from LIB anodes is urgently needed. Herein, the battery powder (BP) was obtained from spent lithium-ion batteries (LIBs) through physical-pyrolysis and sieving. Chemical composition analysis confirmed that the battery used in this work was composed of NCM cathode with high-nickel content and graphite anode material. The average particle size of the obtained BP was 87 μm. In order to obtain the residue having high concentration of carbon, the metal extraction was applied using an HCl solution. As a result, metals (Li, Ni, Co, Mn, Al, Cu, and Fe) in the final remnant were found to be less than 2%, and carbon was found to have a purity of 97% or more. The obtained BP was tested as both the adsorbent and support for indoor CO 2 capture. Various activation treatments were examined to enhance the textural properties of BP. BP-K (K 2 CO 2 impregnated BP) adsorbents were prepared, and their CO 2 adsorption performances were evaluated with CO 2 adsorption isotherms, thermogravimetric analysis (TGA), and 0.1 m 3 chamber (CO 2 IR analyzer) at low CO 2 level (1000–2000 ppm). Through XRD and FT-IR analyses, the adsorption mechanism between K 2 CO 3 and CO 2 under moisture-containing indoor air conditions was confirmed to depend on chemisorption in the following reaction pathway: R1–R3(K 2 CO 3 (s) + H 2 O (g) + CO 2 (g) ⇋ 2KHCO 3 (s) (R1), K 2 CO 3 (s) + 1·.5H 2 O(g) ⇋ K 2 CO 3 ·1·.5H 2 O(s) (R2), K 2 CO 3 ·1·.5H 2 O(s) + CO 2 (g) ⇋ 2KHCO 3 (s) + 0·.5H 2 O(g)(R3)). The adsorption working capacities of the recycled BP-K adsorbents were remained relatively constant during four consecutive cycles. [ABSTRACT FROM AUTHOR]