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Highly microporous adsorbents have been under considerable scrutiny for efficient adsorptive storage of H-2. Of specific interest are sustainable, chemically activated, microporous carbon adsorbents, especially from renewable and organic precursor materials. In this article, six peat-derived microporous carbon materials were synthesized by chemical activation with ZnCl2. N-2 and CO2 gas adsorption data were measured and simultaneously fitted with the 2D-NLDFT-HS model. Thus, based on the obtained results, the use of a low ratio of ZnCl2 for chemical activation of peat-derived carbon yields highly ultramicroporous carbons which are able to adsorb up to 83% of the maximal adsorbed amount of adsorbed H-2 already at 1 bar at 77 K. This is accompanied by the high ratio of micropores, 99%, even at high specific surface area of 1260 m(2) g(-1), exhibited by the peat-derived carbon activated at 973 K using a 1:2 ZnCl2 to peat mass ratio. These results show the potential of using low concentrations of ZnCl2 as an activating agent to synthesize highly ultramicroporous carbon materials with suitable pore characteristics for the efficient low-pressure adsorption of H-2.

Highly microporous adsorbents have been under considerable scrutiny for efficient adsorptive storage of H2. Of specific interest are sustainable, chemically activated, microporous carbon adsorbents, especially from renewable and organic precursor materials. In this article, six peat-derived microporous carbon materials were synthesized by chemical activation with ZnCl2. N2 and CO2 gas adsorption data were measured and simultaneously fitted with the 2D-NLDFT-HS model. Thus, based on the obtained results, the use of a low ratio of ZnCl2 for chemical activation of peat-derived carbon yields highly ultramicroporous carbons which are able to adsorb up to 83% of the maximal adsorbed amount of adsorbed H2 already at 1 bar at 77 K. This is accompanied by the high ratio of micropores, 99%, even at high specific surface area of 1260 m2 g−1, exhibited by the peat-derived carbon activated at 973 K using a 1:2 ZnCl2 to peat mass ratio. These results show the potential of using low concentrations of ZnCl2 as an activating agent to synthesize highly ultramicroporous carbon materials with suitable pore characteristics for the efficient low-pressure adsorption of H2.

Microporous fish waste-based activated carbon material (MFC) was prepared, with a large surface area of 2,193.52 m²/g, a pore size of 2.67 nm and micropore and total pore volumes of 0.9168 cm³/g and 0.9975 cm³/g, respectively. Adsorption efficiency of MFC was investigated by removal of methylene blue dye from wastewater. The Langmuir model and pseudo-second-order kinetics adequately described the adsorption process. MFC exhibited a high adsorption capacity of 476.19 mg/g at 30 °C, and reached equilibrium within 1 h. MFC could be an efficient and low-cost adsorbent for cationic dye removal during wastewater treatment.

This chapter contains sections titled: Introduction [2 + 2] Photodimerization in the Solid State [2 + 2] Photodimerizations Integrated into Mofs Cyclobutanes as Organic Bridges of MOFs Conclusion References

This chapter contains sections titled: Introduction Microporous Carbon Materials Mesoporous Carbon Materials Macroporous Carbon Materials References

Potassium‐ion batteries (PIBs) have been considered as potential alternatives for lithium‐ion batteries since there is a demand for better anode with superior energy, excellent rate capability, and long cyclability. The high‐capacity zinc selenide (ZnSe) anode, which combines the merits of conversion and alloying reactions, is promising for PIBs but suffers from poor cyclability and low electronic conductivity. To effectively boost electrochemical performance of ZnSe, a “dual‐carbon‐confined” structure is constructed, in which an inner N‐doped microporous carbon (NMC)‐coated ZnSe wrapped by outer‐rGO (ZnSe@i‐NMC@o‐rGO) is synthesized. Combining finite element simulation, dynamic analysis, and density functional theory calculations, the respective roles of inner‐ and outer‐carbon in boosting performance are revealed. The inner‐NMC increased the reactivity of ZnSe with K+ and alleviated the volume expansion of ZnSe, while outer‐rGO further stabilized the structure and promoted the reaction kinetics. Benefiting from the synergistic effect of dual‐carbon, ZnSe@i‐NMC@o‐rGO exhibited a high specific capacity 233.4 mAh g−1 after 1500 cycles at 2.0 A g−1. Coupled with activated carbon, a potassium‐ion hybrid capacitor displayed a high energy density of 176.6 Wh kg−1 at 1800 W kg−1 and a superior capacity retention of 82.51% at 2.0 A g−1 after 11000 cycles. An inner N‐doped microporous carbon (NMC) coated ZnSe wrapped by outer‐rGO (ZnSe@i‐NMC@o‐rGO) is synthesized. As expected, the ZnSe@i‐NMC@o‐rGO with “dual‐carbon confinement” structure is used to assemble potassium‐ion hybrid capacitors, exhibiting an extraordinarily energy density of 176.6 Wh kg−1 at 1800 W kg−1 and a superior capacity retention of 82.51% even after 11 000 cycles.

Microporous organic polymers (MOPs) are technologically important for low-dielectric materials, gas separation and gas-storage applications. A class of amorphous MOPs prepared by cycloaddition modification is shown to exhibit outstanding CO 2 separation performance and super-permeable characteristics Microporous organic polymers (MOPs) are of potential significance for gas storage 1 , 2 , 3 , gas separation 4 and low-dielectric applications 5 . Among many approaches for obtaining such materials, solution-processable MOPs derived from rigid and contorted macromolecular structures are promising because of their excellent mass transport and mass exchange capability. Here we show a class of amorphous MOP, prepared by [2+3] cycloaddition modification of a polymer containing an aromatic nitrile group with an azide compound, showing super-permeable characteristics and outstanding CO 2 separation performance, even under polymer plasticization conditions such as CO 2 /light gas mixtures. This unprecedented result arises from the introduction of tetrazole groups into highly microporous polymeric frameworks, leading to more favourable CO 2 sorption with superior affinity in gas mixtures, and selective CO 2 transport by presorbed CO 2 molecules that limit access by other light gas molecules. This strategy provides a direction in the design of MOP membrane materials for economic CO 2 capture processes.

Rising carbon dioxide (CO2) levels in the atmosphere are recognized as a threat to atmospheric stability and life. Although this greenhouse gas is being produced on a large scale, there are solutions to reduction and indeed utilization of the gas. Many of these solutions involve costly or unstable technologies, such as air‐sensitive metal–organic frameworks (MOFs) for CO2 capture or “non‐green” systems such as amine scrubbing. Conjugated microporous polymers (CMPs) represent a simpler, cheaper, and greener solution to CO2 capture and utilization. They are often easy to synthesize at scale (a one pot reaction in many cases), chemically and thermally stable (especially in comparison with their MOF and covalent organic framework (COF) counterparts, owing to their amorphous nature), and, as a result, cheap to manufacture. Furthermore, their large surface areas, tunable porous frameworks and chemical structures mean they are reported as highly efficient CO2 capture motifs. In addition, they provide a dual pathway to utilize captured CO2 via chemical conversion or electrochemical reduction into industrially valuable products. Recent studies show that all these attractive properties can be realized in metal‐free CMPs, presenting a truly green option. The promising results in these two fields of CMP applications are reviewed and explored here. Conjugated microporous polymers (CMPs) enable the chemical conversion or electrochemical reduction of CO2, resulting in the production of industrially valuable products. Recent studies demonstrate that these desirable properties can be attained in metal‐free CMPs, offering a route to sustainable and green long‐term solutions. This review provides an overview of the use of these promising materials to address globally significant challenges.

HighlightsAn ultra-microporous carbon material simultaneously with high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3) is designed and fabricated.The resulting carbon material integrates the high gravimetric and volumetric capacitance (430 F g−1 and 507 F cm−3 at 0.5 A g−1) and thereof provides the robust all-solid-state cellulose supercapacitor with high areal and volumetric density.A breakthrough in advancing power density and stability of carbon-based supercapacitors is trapped by inefficient pore structures of electrode materials. Herein, an ultra-microporous carbon with ultrahigh integrated capacitance fabricated via one-step carbonization/activation of dense bacterial cellulose (BC) precursor followed by nitrogen/sulfur dual doping is reported. The microporous carbon possesses highly concentrated micropores (~ 2 nm) and a considerable amount of sub-micropores (< 1 nm). The unique porous structure provides high specific surface area (1554 m2 g−1) and packing density (1.18 g cm−3). The synergistic effects from the particular porous structure and optimal doping effectively enhance ion storage and ion/electron transport. As a result, the remarkable specific capacitances, including ultrahigh gravimetric and volumetric capacitances (430 F g−1 and 507 F cm−3 at 0.5 A g−1), and excellent cycling and rate stability even at a high current density of 10 A g−1 (327 F g−1 and 385 F cm−3) are realized. Via compositing the porous carbon and BC skeleton, a robust all-solid-state cellulose-based supercapacitor presents super high areal energy density (~ 0.77 mWh cm−2), volumetric energy density (~ 17.8 W L−1), and excellent cyclic stability.

Biobased carbon materials (BBC) obtained from Norway spruce (Picea abies Karst.) bark was produced by single-step chemical activation with ZnCl2 or KOH, and pyrolysis at 800 °C for one hour. The chemical activation reagent had a significant impact on the properties of the BBCs. KOH-biobased carbon material (KOH-BBC) had a higher specific surface area (SBET), equal to 1067 m2 g−1, larger pore volume (0.558 cm3 g−1), more mesopores, and a more hydrophilic surface than ZnCl2-BBC. However, the carbon yield for KOH-BBC was 63% lower than for ZnCl2-BBC. Batch adsorption experiments were performed to evaluate the ability of the two BBCs to remove two dyes, reactive orange 16 (RO-16) and reactive blue 4 (RB-4), and treat synthetic effluents. The general order model was most suitable for modeling the adsorption kinetics of both dyes and BBCs. The equilibrium parameters at 22 °C were calculated using the Liu model. Upon adsorption of RO-16, Qmax was 90.1 mg g−1 for ZnCl2-BBC and 354.8 mg g−1 for KOH-BBC. With RB-4, Qmax was 332.9 mg g−1 for ZnCl2-BBC and 582.5 mg g−1 for KOH-BBC. Based on characterization and experimental data, it was suggested that electrostatic interactions and hydrogen bonds between BBCs and RO-16 and RB-4 dyes played the most crucial role in the adsorption process. The biobased carbon materials showed high efficiency for removing RO-16 and RB-4, comparable to the best examples from the literature. Additionally, both the KOH- and ZnCl2-BBC showed a high ability to purify two synthetic effluents, but the KOH-BBC was superior.