A Robust 3D Cage‐like Ultramicroporous Network Structure with High Gas‐Uptake Capacity

A three‐dimensional (3D) cage‐like organic network (3D‐CON) structure synthesized by the straightforward condensation of building blocks designed with gas adsorption properties is presented. The 3D‐CON can be prepared using an easy but powerful route, which is essential for commercial scale‐up. The resulting fused aromatic 3D‐CON exhibited a high Brunauer–Emmett–Teller (BET) specific surface area of up to 2247 m² g^?1. More importantly, the 3D‐CON displayed outstanding low pressure hydrogen (H₂, 2.64 wt %, 1.0 bar and 77 K), methane (CH₄, 2.4 wt %, 1.0 bar and 273 K), and carbon dioxide (CO₂, 26.7 wt %, 1.0 bar and 273 K) uptake with a high isosteric heat of adsorption (H₂, 8.10 kJ mol^?1; CH₄, 18.72 kJ mol^?1; CO₂, 31.87 kJ mol^?1). These values are among the best reported for organic networks with high thermal stability (ca. 600 °C).     

Synthesis of High‐Surface‐Area Nitrogen‐Doped Porous Carbon Microflowers and Their Efficient Carbon Dioxide Capture Performance

Sustainable carbon materials have received particular attention in CO₂ capture and storage owing to their abundant pore structures and controllable pore parameters. Here, we report high‐surface‐area hierarchically porous N‐doped carbon microflowers, which were assembled from porous nanosheets by a three‐step route: soft‐template‐assisted self‐assembly, thermal decomposition, and KOH activation. The hydrazine hydrate used in our experiment serves as not only a nitrogen source, but also a structure‐directing agent. The activation process was carried out under low (KOH/carbon=2), mild (KOH/carbon=4) and severe (KOH/carbon=6) activation conditions. The mild activated N‐doped carbon microflowers (A‐NCF‐4) have a hierarchically porous structure, high specific surface area (2309 m² g^?1), desirable micropore size below 1 nm, and importantly large micropore volume (0.95 cm³ g^?1). The remarkably high CO₂ adsorption capacities of 6.52 and 19.32 mmol g^?1 were achieved with this sample at 0 °C (273 K) and two pressures, 1 bar and 20 bar, respectively. Furthermore, this sample also exhibits excellent stability during cyclic operations and good separation selectivity for CO₂ over N₂.     

Porous‐Organic‐Framework‐Templated Nitrogen‐Rich Porous Carbon as a More Proficient Electrocatalyst than Pt/C for the Electrochemical Reduction of Oxygen

Porous nitrogen‐rich carbon (POF‐C‐1000) that was synthesized by using a porous organic framework (POF) as a self‐sacrificing host template in a nanocasting process possessed a high degree of graphitization in an ordered structural arrangement with large domains and well‐ordered arrays of carbon sheets. POF‐C‐1000 exhibits favorable electrocatalytic activity for the oxygen‐reduction reaction (ORR) with a clear positive shift of about 40 mV in the onset potential compared to that of a traditional, commercially available Pt/C catalyst. In addition, irrespective of its moderate surface area (785 m² g^?1), POF‐C‐1000 showed a reasonable H₂ adsorption of 1.6 wt % (77 K) and a CO₂ uptake of 3.5 mmol g^?1 (273 K).     

A Versatile CuII Metal–Organic Framework Exhibiting High Gas Storage Capacity with Selectivity for CO2: Conversion of CO2 to Cyclic Carbonate and Other Catalytic Abilities

A linear tetracarboxylic acid ligand, H₄L, with a pendent amine moiety solvothermally forms two isostructural metal–organic frameworks (MOFs) L_M (M=Zn^II, Cu^II). Framework L_Cu can also be obtained from L_Zn by post‐ synthetic metathesis without losing crystallinity. Compared with L_Zn , the L_Cu framework exhibits high thermal stability and allows removal of guest solvent and metal‐bound water molecules to afford the highly porous, L_Cu′ . At 77 K, L_Cu′ absorbs 2.57 wt % of H₂ at 1 bar, which increases significantly to 4.67 wt % at 36 bar. The framework absorbs substantially high amounts of methane (238.38 cm³ g^?1, 17.03 wt %) at 303 K and 60 bar. The CH₄ absorption at 303 K gives a total volumetric capacity of 166 cm³ (STP) cm^?3 at 35 bar (223.25 cm³ g^?1, 15.95 wt %). Interestingly, the NH₂ groups in the linker, which decorate the channel surface, allow a remarkable 39.0 wt % of CO₂ to be absorbed at 1 bar and 273 K, which comes within the dominion of the most famous MOFs for CO₂ absorption. Also, L_Cu′ shows pronounced selectivity for CO₂ absorption over CH₄, N₂, and H₂ at 273 K. The absorbed CO₂ can be converted to value‐added cyclic carbonates under relatively mild reaction conditions (20 bar, 120 °C). Finally, L_Cu′ is found to be an excellent heterogeneous catalyst in regioselective 1,3‐dipolar cycloaddition reactions (“click” reactions) and provides an efficient, economic route for the one‐pot synthesis of structurally divergent propargylamines through three‐component coupling of alkynes, amines, and aldehydes.     

Microporous Polymers from a Carbazole‐Based Triptycene Monomer: Synthesis and Their Applications for Gas Uptake

Two kinds of novel organic microporous polymers TCP s ( TCP‐A and TCP‐B ) were prepared by two cost‐effective synthetic strategies from the monomer of tricarbazolyltriptycene ( TCT ). Their structure and properties were characterized by FT‐IR, solid ¹³C NMR, powder XRD, SEM, TEM, and gas absorption measurements. TCP‐B displayed a high surface area (1469 m² g^?1) and excellent H₂ storage (1.70 wt % at 1 bar/77 K) and CO₂ uptake abilities (16.1 wt % at 1 bar/273 K), which makes it a promising material for potential application in gas storage.     

Water‐Stable Zirconium‐Based Metal–Organic Framework Material with High‐Surface Area and Gas‐Storage Capacities

We designed, synthesized, and characterized a new Zr‐based metal–organic framework material, NU‐1100 , with a pore volume of 1.53 ccg^?1 and Brunauer–Emmett–Teller (BET) surface area of 4020 m²g^?1; to our knowledge, currently the highest published for Zr‐based MOFs. CH₄/CO₂/H₂ adsorption isotherms were obtained over a broad range of pressures and temperatures and are in excellent agreement with the computational predictions. The total hydrogen adsorption at 65 bar and 77 K is 0.092 g g^?1, which corresponds to 43 g L^?1. The volumetric and gravimetric methane‐storage capacities at 65 bar and 298 K are approximately 180 v_STP/v and 0.27 g g^?1, respectively.     

Synthesis of Two‐dimensional Microporous Carbonaceous Polymer Nanosheets and Their Application as High‐performance CO2 Capture Sorbent

The synthesis of two‐dimensional (2D) polymer nanosheets with a well‐defined microporous structure remains challenging in materials science. Here, a new kind of 2D microporous carbonaceous polymer nanosheets was synthesized through polymerization of a very low concentration of 1,4‐dicyanobenzene in molten zinc chloride at 400–500 °C. This type of nanosheets has a thickness in the range of 3–20 nm, well‐defined microporosity, a high surface area (～537 m² g^?1), and a large micropore volume (～0.45 cm³ g^?1). The microporous carbonaceous polymer nanosheets exhibit superior CO₂ sorption capability (8.14 wt % at 298 K and 1 bar) and a relatively high CO₂ selectivity toward N₂ (25.6). Starting from different aromatic nitrile monomers, a variety of 2D carbonaceous polymer nanosheets can be obtained showing a certain universality of the ionothermal method reported herein.     

New Multifunctional Porous Materials Based on Inorganic–Organic Hybrid Single‐Walled Carbon Nanotubes: Gas Storage and High‐Sensitive Detection of Pesticides

Single‐walled carbon nanotubes (SWNTs) that are covalently functionalized with benzoic acid (SWNT‐PhCOOH) can be integrated with transition‐metal ions to form 3D porous inorganic–organic hybrid frameworks (SWNT‐Zn). In particular, N₂‐adsorption analysis shows that the BET surface area increases notably from 645.3 to 1209.9 m² g^?1 for SWNTs and SWNT‐Zn, respectively. This remarkable enhancement in the surface area of SWNT‐Zn is presumably due to the microporous motifs from benzoates coordinated to intercalated zinc ions between the functionalized SWNTs; this assignment was also corroborated by NLDFT pore‐size distributions. In addition, the excess‐H₂‐uptake maximum of SWNT‐Zn reaches about 3.1 wt. % (12 bar, 77 K), which is almost three times that of the original SWNTs (1.2 wt. % at 12 bar, 77 K). Owing to its inherent conductivity and pore structure, as well as good dispersibility, SWNT‐Zn is an effective candidate as a sensitive electrochemical stripping voltammetric sensor for organophosphate pesticides (OPs): By using solid‐phase extraction (SPE) with SWNT‐Zn‐modified glassy carbon electrode, the detection limit of methyl parathion (MP) is 2.3 ng mL^?1.     

Synthesis of Hierarchically Porous Sandwich‐Like Carbon Materials for High‐Performance Supercapacitors

For the first time, hierarchically porous carbon materials with a sandwich‐like structure are synthesized through a facile and efficient tri‐template approach. The hierarchically porous microstructures consist of abundant macropores and numerous micropores embedded into the crosslinked mesoporous walls. As a result, the obtained carbon material with a unique sandwich‐like structure has a relatively high specific surface (1235 m² g^?1), large pore volume (1.30 cm³ g^?1), and appropriate pore size distribution. These merits lead to a comparably high specific capacitance of 274.8 F g^?1 at 0.2 A g^?1 and satisfying rate performance (87.7 % retention from 1 to 20 A g^?1). More importantly, the symmetric supercapacitor with two identical as‐prepared carbon samples shows a superior energy density of 18.47 Wh kg^?1 at a power density of 179.9 W kg^?1. The asymmetric supercapacitor based on as‐obtained carbon sample and its composite with manganese dioxide (MnO₂) can reach up to an energy density of 25.93 Wh kg^?1 at a power density of 199.9 W kg^?1. Therefore, these unique carbon material open a promising prospect for future development and utilization in the field of energy storage.     

An Azine‐Linked Covalent Organic Framework: Synthesis,Characterization and Efficient Gas Storage

A azine‐linked covalent organic framework, COF‐JLU2, was designed and synthesized by condensation of hydrazine hydrate and 1,3,5‐triformylphloroglucinol under solvothermal conditions for the first time. The new covalent organic framework material combines permanent micropores, high crystallinity, good thermal and chemical stability, and abundant heteroatom activated sites in the skeleton. COF‐JLU2 possesses a moderate BET surface area of over 410 m² g^?1 with a pore volume of 0.56 cm³ g^?1. Specifically, COF‐JLU2 displays remarkable carbon dioxide uptake (up to 217 mg g^?1) and methane uptake (38 mg g^?1) at 273 K and 1 bar, as well as high CO₂/N₂ (77) selectivity. Furthermore, we further highlight that it exhibits a higher hydrogen storage capacity (16 mg g^?1) than those of reported COFs at 77 K and 1 bar.     

Hierarchical Activated Mesoporous Phenolic‐Resin‐Based Carbons for Supercapacitors

A series of hierarchical activated mesoporous carbons (AMCs) were prepared by the activation of highly ordered, body‐centered cubic mesoporous phenolic‐resin‐based carbon with KOH. The effect of the KOH/carbon‐weight ratio on the textural properties and capacitive performance of the AMCs was investigated in detail. An AMC prepared with a KOH/carbon‐weight ratio of 6:1 possessed the largest specific surface area (1118 m² g^?1), with retention of the ordered mesoporous structure, and exhibited the highest specific capacitance of 260 F g^?1 at a current density of 0.1 A g^?1 in 1 M H₂SO₄ aqueous electrolyte. This material also showed excellent rate capability (163 F g^?1 retained at 20 A g^?1) and good long‐term electrochemical stability. This superior capacitive performance could be attributed to a large specific surface area and an optimized micro‐mesopore structure, which not only increased the effective specific surface area for charge storage but also provided a favorable pathway for efficient ion transport.     

Polymer Composite Membrane with Penetrating ZIF‐7 Sheets Displays High Hydrogen Permselectivity

Oriented and penetrating molecular sieving membranes display enhanced separation performance. A polyimide (PI) solution containing highly dispersed ZIF‐7(III) sheets in CHCl₃ was deposited on a glass side and subjected to flat‐scraping with a membrane fabricator. In this way we developed a novel oriented and penetrating ZIF‐7@PI mixed matrix membrane (MMM) with 50 wt. % ZIF‐7 loading. Because the height of the ZIF‐7 sheets (5 μm) is higher than the film thickness, every ZIF‐7 sheet penetrates both surfaces of the polyimide film. Since the ZIF‐7 channels are the dominant pathway for gas permeation, the ZIF‐7@PI MMM displays a high molecular sieve performance for the separation of H₂ (0.29 nm) from larger gas molecules. At 100 °C and 2 bar, the mixture separation factors of H₂/CO₂ and H₂/CH₄ are 91.5 and 128.4, with a high H₂ permeance of about 3.0×10^?7 mol m^?2 s^?1 Pa^?1, which is promising for hydrogen separation by molecular sieving.     

Octa[4‐(9‐carbazolyl)phenyl]silsesquioxane‐Based Porous Material for Dyes Adsorption and Sensing of Nitroaromatic Compounds

A new fluorescent hybrid porous polymer (HPP) is synthesized by an anhydrous FeCl₃‐mediated oxidative coupling reaction of octa[4‐(9‐carbazolyl)phenyl]silsesquioxane (OCPS). The polymer possesses a surface area of 1741 m² g^?1 and hierarchical bimodal micropores (1.41 and 1.69 nm) and mesopores (2.65 nm). The material serves as an excellent adsorbent for CO₂ and dyes with high adsorption capacity for CO₂ (8.53 wt %,1.94 mmol g^?1), congo red (1715 mg g^?1) and rhodamine B (1501 mg g^?1). In addition, the presence of peripheral cabozolyl groups with extended π‐conjugation in the crosslinked framework imparts luminescent character to the polymer and offers the detection of nitroaromatic compounds.     

Synthesis of Nanostructured Carbon through Ionothermal Carbonization of Common Organic Solvents and Solutions

A combination of ionothermal synthesis and hot‐injection techniques leads to novel nanocarbons made from organic solvents. Controlled addition of commonly used organic solvents into a hot ZnCl₂ melt gives rise to spherical, sheetlike, and branched nanofibrous carbon nanoparticles with surprisingly high carbon efficiency. When heteroatom‐containing solvents were used, the doping levels reach up to 14 wt. % nitrogen and 13 wt. % sulfur. Materials with high surface areas and large pore volumes of solvent carbons as high as 1666 m² g^?1 and 2.80 cm³ g^?1 in addition to CO₂ adsorption capacities of 4.13 mmol g^?1 at 273 K and 1 bar can be obtained. The new method works not only for pure carbon materials, but was also extended for the synthesis of carbon/inorganic nanocomposites. ZnS@C, Ni@C, and Co@C were successfully prepared with this straightforward procedure. The obtained Ni@C nanocomposites perform well in the electrocatalytic water oxidation, comparable with commercial noble‐metal catalysts.     

In Situ Pyrolysis Tracking and Real‐Time Phase Evolution: From a Binary Zinc Cluster to Supercapacitive Porous Carbon

The in situ tracking of the pyrolysis of a binary molecular cluster [Zn₇(μ₃‐CH₃O)₆(L)₆][ZnLCl₂]₂ is presented with one brucite disk and two mononuclear fragments (L=mmimp: 2‐methoxy‐6‐((methylimino)‐methyl)phenolate) to porous carbon using TG‐MS from 30 to 900 °C. Following up the spilled gas product during the decomposed reaction of zinc cluster along the temperature rising, and in conjunction with XRD, SEM, BET and other materials characterization, where three key steps were observed: 1) cleavage of the bulky external ligand; 2) reduction of ZnO and 3) volatilization of Zn. The real‐time‐dependent phase‐sequential evolution of the remaining products and the processing of pore forming template transformation are proposed simultaneously. The porous carbon structure featuring a uniform nano‐sized pore distribution synthesized at 900 °C with the highest surface area of 1644 m² g^?1 and pore volume of 0.926 cm³ g^?1 exhibits the best known capacitance of 662 F g^?1 at 0.5 A g^?1.     

3D Hexagonal Mesoporous Silica and Its Organic Functionalization for High CO2 Uptake

Highly ordered 3D‐hexagonal mesoporous silica HMS‐3 and its vinyl‐ and 3‐chloropropyl‐functionalized analogues HMS‐4 and ‐5, respectively, are synthesized under strongly alkaline conditions at 277 K. Tetraethyl orthosilicate, vinyltrimethoxysilane, and 3‐chloropropyltrimethoxysilane are used as silica sources, and cetyltrimethylammonium bromide as the structure‐directing agent. The 3D‐hexagonal pore structures of HMS‐3, 4‐, and ‐5 were confirmed by powder XRD and high‐resolution TEM studies. Brunauer–Emmett–Teller surface areas of these materials are 1353, 1211, and 603 m² g^?1 for HMS‐3, ‐4, and ‐5, respectively. Among these materials, vinyl‐functionalized mesoporous material HMS‐4 adsorbs the highest CO₂ (5.5 mmol g^?1, 24.3 wt %) under 3 bar pressure at 273 K. The 3D‐hexagonal pore openings, very high surface area, and cagelike mesopores as well as organic functionalization could be responsible for very high CO₂ uptakes of these materials compared to other related mesoporous silica‐based materials.     

Eosin Y‐Functionalized Conjugated Organic Polymers for Visible‐Light‐Driven CO2 Reduction with H2O to CO with High Efficiency

Visible‐light‐driven photoreduction of CO₂ to energy‐rich chemicals in the presence of H₂O without any sacrifice reagent is of significance, but challenging. Herein, Eosin Y‐functionalized porous polymers (PEosinY‐N, N=1–3), with high surface areas up to 610 m² g^?1, are reported. They exhibit high activity for the photocatalytic reduction of CO₂ to CO in the presence of gaseous H₂O, without any photosensitizer or sacrifice reagent, and under visible‐light irradiation. Especially, PEosinY‐1 derived from coupling of Eosin Y with 1,4‐diethynylbenzene shows the best performance for the CO₂ photoreduction, affording CO as the sole carbonaceous product with a production rate of 33 μmol g^?1 h^?1 and a selectivity of 92 %. This work provides new insight for designing and fabricating photocatalytically active polymers with high efficiency for solar‐energy conversion.     

Metal Microporous Aromatic Polymers with Improved Performance for Small Gas Storage

A novel metal‐doping strategy was developed for the construction of iron‐decorated microporous aromatic polymers with high small‐gas‐uptake capacities. Cost‐effective ferrocene‐functionalized microporous aromatic polymers (FMAPs) were constructed by a one‐step Friedel–Crafts reaction of ferrocene and s‐triazine monomers. The introduction of ferrocene endows the microporous polymers with a regular and homogenous dispersion of iron, which avoids the slow reunion that is usually encountered in previously reported metal‐doping procedures, permitting a strong interaction between the porous solid and guest gases. Compared to ferrocene‐free analogues, FMAP‐1, which has a moderate BET surface area, shows good gas‐adsorption capabilities for H₂ (1.75 wt % at 77 K/1.0 bar), CH₄ (5.5 wt % at 298 K/25.0 bar), and CO₂ (16.9 wt % at 273 K/1.0 bar), as well as a remarkably high ideal adsorbed solution theory CO₂/N₂ selectivity (107 v/v at 273 K/(0–1.0) bar), and high isosteric heats of adsorption of H₂ (16.9 kJ mol^?1) and CO₂ (41.6 kJ mol^?1).     

Enhanced CO2 Adsorption Affinity in a NbO‐type MOF Constructed from a Low‐Cost Diisophthalate Ligand with a Piperazine‐Ring Bridge

A metal–organic framework (NPC‐6) with an NbO topology based on a piperazine ring‐bridged diisophthalate ligand was synthesized and characterized. The incorporated piperazine group leads to an enhanced adsorption affinity for CO₂ in NPC‐6, in which the CO₂ uptake is 4.83 mmol g^?1 at 293 K and 1 bar, ranking among the top values of CO₂ uptake on MOF materials. At 0.15 bar and 293 K, the NPC‐6 adsorbs 1.07 mmol g^?1 of CO₂, which is about 55.1 % higher than that of the analogue MOF NOTT‐101 under the same conditions. The enhanced CO₂ uptake combined with comparable uptakes for CH₄ and N₂ leads to much higher selectivities for CO₂/CH₄ and CO₂/N₂ gas mixtures on NPC‐6 than on NOTT‐101. Furthermore, an N‐alkylation is used in the synthesis of the PDIA ligand, leading to a much lower cost compared with that in the synthesis of ligands in the NOTT series, as the former does not require a palladium‐based catalyst and borate esters. Thus, we conclude that NPC‐6 is a promising candidate for CO₂ capture applications.     

A New Synthetic Route to Microporous Silica with Well‐Defined Pores by Replication of a Metal–Organic Framework

Microporous amorphous hydrophobic silica materials with well‐defined pores were synthesized by replication of the metal–organic framework (MOF) [Cu₃(1,3,5‐benzenetricarboxylate)₂] (HKUST‐1). The silica replicas were obtained by using tetramethoxysilane or tetraethoxysilane as silica precursors and have a micro–meso binary pore system. The BET surface area, the micropore volume, and the mesopore volume of the silica replica, obtained by means of hydrothermal treatment at 423 K with tetraethoxysilane, are 620 m²g^?1, 0.18 mL g^?1, and 0.55 mL g^?1, respectively. Interestingly, the silica has micropores with a pore size of 0.55 nm that corresponds to the pore‐wall thickness of the template MOF. The silica replica is hydrophobic, as confirmed by adsorption analyses, although the replica has a certain amount of silanol groups. This hydrophobicity is due to the unique condensation environment of the silica precursors in the template MOF.