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[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]

Thiol-functionalized ZIF-90 (ZIF-90-SH) was prepared via condensation of the free aldehyde group of ZIF-90 with 2-mercaptoethylamine to an imine through a one-step post-synthesis route. A subsequent reaction with manganese(ii) acetate resulted in the formation of a new Mn(ii)-immobilized hybrid material (ZIF-90-S[Mn]). This material was characterized by chemical analysis, X-ray diffraction, N2 adsorption–desorption, thermogravimetric analysis and Fourier transform infrared spectroscopy, which confirmed the successful functionalization of the as-synthesized ZIF-90. ZIF-90-SH employed as an adsorbent for the removal of Hg(ii) ions from an aqueous solution at room temperature exhibited an adsorption capacity of ca. 22.4 mg g−1. The material showed 96–98% removal of Hg(ii) ions in a low concentration range (0.1 to 10.0 mg L−1). ZIF-90-S[Mn] showed good catalytic activity and selectivity in the epoxidation of several important alkenes using molecular oxygen under atmospheric pressure. Recycling and hot filtration experiments coupled with a blank test showed that epoxidation proceeded over ZIF-90-S[Mn] on the external surface of the ZIF-90 matrices, where the active Mn(ii) sites were located. The catalyst could be recycled up to four times without significant loss of efficiency. [ABSTRACT FROM AUTHOR]

High performance adsorption of Gd3+ by the second generation poly(amidoamine) dendrimer immobilized on mesoporous silica foam (MSF) and fibrous nano-silica KCC-1. • Poly(amidoamine) dendrimer was grafted on mesoporous silica foam and fibrous silica KCC-1. • The prepared adsorbents were extensively characterized after each preparation step. • Gd3+ adsorption over the adsorbents was examined under various experimental conditions. • Mesoporous silica foam was more effective as a host than KCC-1 for the dendrimer. • High adsorption capacity and recyclability with good selectivity were confirmed. Separation and recovery of low concentration rare earth elements (REEs) from aqueous environment need to be considered to meet their growing demand for high-technology devices. In this work, the second-generation poly(amidoamine) dendrimers immobilized on a mesoporous silica foam (MSF) or a fibrous nano-silica KCC-1 (PAMAM@GTA-NH 2 -MSF and PAMAM@GTA-NH 2 -KCC-1, respectively) were prepared after systematic grafting of 3-aminopropyltriethoxysilane and glutaraldehyde (GTA) as a cross-linking spacer. These were investigated for recovery of gadolinium ions (Gd3+) in water via adsorption. The prepared adsorbents were extensively characterized in each preparation step by various analytical instruments, and successful attachment of the organic groups on the silica supports was confirmed. The Gd3+ adsorption over the functionalized materials was examined under different conditions of the solution pH, initial Gd3+ concentrations, and adsorption time. PAMAM@GTA-NH 2 -MSF performed better than PAMAM@GTA-NH 2 -KCC-1, with exceptionally high adsorption capacity (ca. 132 mg/g) and recyclability with reasonable selectivity for potential commercial use. Gd3+ selectivity against competing ions could be further enhanced to ca. 86% by successive functionalization with N-(phosphonomethyl) iminodiacetic acid on PAMAM@GTA-NH 2 -MSF. [ABSTRACT FROM AUTHOR]

[Display omitted] • The working capacity and stability of absorbent were studied for CO 2 capture. • MPS-supported epoxide-functionalization of PEHA absorbent was synthesized. • PO-PEHA/MPS adsorbent exhibited the working capacity of 1.8 mmol g−1 in 20 cycle. • When the adsorption time was reduced, the regeneration heat was 2.86 GJ tCO 2 -1. • Adsorbent that is regenerated in 100% CO 2 , not inert (N 2 , He) conditions was developed. N -functionalized solid adsorbents have been studied for post-combustion CO 2 capture. Most studies have focused only on the adsorption condition of the adsorbents. Few studies have focused on the regeneration condition of adsorbents. Regeneration is required under the condition of 100 % CO 2 for high-purity CO 2 separation. Regeneration under inert conditions such as N 2 or He, not under the condition of 100 % CO 2 regeneration are required additional cost for high-purity CO 2 separation. In this study, a macroporous silica (MPS) support, which combined a high surface area, large porosity and large pore volume, was selected as the support to achieve high CO 2 capture performance. Pentaethylenehexamine (PEHA) was selected because of its high amine content, high adsorption capacity, high thermal stability, and low cost. The epoxide functionalization of PEHA was used to suppress the urea formation under regeneration conditions. The working capacity and cyclic stability of epoxide functionalization of MPS-based PEHA adsorbents were investigated. A working capacity of 1.8 mmol g−1 was maintained by repeating adsorption and desorption experiments 20 times under an adsorption condition of 15 % CO 2 and a desorption condition of 100 % CO 2. Additionally, the stability of the adsorbent under a 100 % CO 2 regeneration condition was confirmed by maintaining the working capacity constant during 20 repeated adsorption and desorption cycle experiments. When the adsorption time was reduced to minimize H 2 O adsorption, the regeneration heat of the adsorbent was 2.86 GJ tCO 2 -1. These results demonstrated that the regeneration ability was excellent under the condition of 100 % CO 2 , which is the actual process application condition. This approach is promising for industrial applications of CO 2 capture technology. [ABSTRACT FROM AUTHOR]