Chemically Activated Covalent Triazine Frameworks with Enhanced Textural Properties for High Capacity Gas Storage

Porous organic polymers (POPs) for environmental remediation

Modern global industrialization along with the ever-increasing growth of the population has resulted in continuous enhancement in the discharge and accumulation of various toxic and hazardous chemicals in the environment. These harmful pollutants, including toxic gases, inorganic heavy metal ions, anthropogenic waste, persistent organic pollutants, toxic dyes, pharmaceuticals, volatile organic compounds, etc., are destroying the ecological balance of the environment. Therefore, systematic monitoring and effective remediation of these toxic pollutants either by adsorptive removal or by catalytic degradation are of great significance. From this viewpoint, porous organic polymers (POPs), being two- or three-dimensional polymeric materials, constructed from small organic molecules connected with rigid covalent bonds have come forth as a promising platform toward various leading applications, especially for efficient environmental remediation. Their unique chemical and structural features including high stability, tunable pore functionalization, and large surface area have boosted the transformation of POPs into various macro-physical forms such as thick and thin-film membranes, which led to a new direction in advanced level pollutant removal, separation and catalytic degradation. In this review, our focus is to highlight the recent progress and achievements in the strategic design, synthesis, architectural-engineering and applications of POPs and their composite materials toward environmental remediation. Several strategies to improve the adsorption efficiency and catalytic degradation performance along with the in-depth interaction mechanism of POP-based materials have been systematically summarized. In addition, evolution of POPs from regular powder form application to rapid and more efficient size and chemo-selective, "real-time" applicable membrane-based application has been further highlighted. Finally, we put forward our perspective on the challenges and opportunities of these materials toward real-world implementation and future prospects in next generation remediation technology.

Hexaazatrinaphthalene-Based Covalent Triazine Framework-Supported Rhodium(III) Complex: A Recyclable Heterogeneous Catalyst for the Reductive Amination of Ketones to Primary Amines

The development of efficient and recyclable heterogeneous catalysts is an important topic. Herein, a rhodium(III) complex Cp*Rh@HATN-CTF was synthesized by the coordinative immobilization of [Cp*RhCl₂]₂ on a hexaazatrinaphthalene-based covalent triazine framework. In the presence of Cp*Rh@HATN-CTF (1 mo l% Rh), a series of primary amines could be obtained via the reductive amination of ketones in high yields. Moreover, catalytic activity of Cp*Rh@HATN-CTF is well maintained during six runs. The present catalytic system was also applied for the large scale preparation of a biologically active compound. It would facilitate the development of CTF-supported transition metal catalysts for sustainable chemistry.

Portable and on-site electrochemical sensor based on surface molecularly imprinted magnetic covalent organic framework for the rapid detection of tetracycline in food

In this study, for the first time, surface molecularly imprinted magnetic covalent organic frameworks (Fe₃O₄@COFs@MIPs) were combined with disposable screen-printed electrode (SPE) to construct a portable and on-site electrochemical sensor for the rapid detection of tetracycline (TC). The Fe₃O₄@COFs@MIPs, which was prepared by layer-by-layer modification method, had good magnetism and excellent adsorption ability. With the help of disposable SPE, equipped with a magnet, the electrode modification process was simplified and the detection efficiency was improved. Under optimal conditions, the fabricated electrochemical sensor exhibited linearity ranging from 1 × 10^-10 to 1 × 10^-4 g mL^-1. It had good selectivity, excellent reproducibility, desirable stability and remarkable applicability. The fabricated sensor was successfully applied to detect TC in real samples with satisfactory recoveries (96.15-106.20%). The detection strategy separated the recognition and adsorption process from the electrochemical detection process, providing a design idea for the application of COFs in the construction of high-efficiency molecularly imprinted electrochemical sensors.

Graphitic Aza-Fused π-Conjugated Networks: Construction, Engineering, and Task-Specific Applications

2D π-conjugated networks linked by aza-fused units represent a pivotal category of graphitic materials with stacked nanosheet architectures. Extensive efforts have been directed at their fabrication and application since the discovery of covalent triazine frameworks (CTFs). Besides the triazine cores, tricycloquinazoline and hexaazatriphenylene linkages are further introduced to tailor the structures and properties. Diverse related materials have been developed rapidly, and a thorough outlook is necessitated to unveil the structure-property-application relationships across multiple subcategories, which is pivotal to guide the design and fabrication toward enhanced task-specific performance. Herein, the structure types and development of related materials including CTFs, covalent quinazoline networks, and hexaazatriphenylene networks, are introduced. Advanced synthetic strategies coupled with characterization techniques provide powerful tools to engineer the properties and tune the associated behaviors in corresponding applications. Case studies in the areas of gas adsorption, membrane-based separation, thermo-/electro-/photocatalysis, and energy storage are then addressed, focusing on the correlation between structure/property engineering and optimization of the corresponding performance, particularly the preferred features and strategies in each specific field. In the last section, the underlying challenges and opportunities in construction and application of this emerging and promising material category are discussed.

Nanostructured Hypercrosslinked Porous Organic Polymers: Morphological Evolution and Rapid Separation of Polar Organic Micropollutants

Nanostructured hypercrosslinked porous organic polymers have triggered immense research interest for a broad spectrum of applications ranging from catalysis to molecular separation. However, it still remains a challenge to tune their nanoscale morphology. Herein, we demonstrated a remarkable variation of morphologies of triptycene-based hypercrosslinked microporous polymers starting from irregular aggregates (FCTP) to rigid spheres (SCTP) to two-dimensional nanosheets (SKTP) from three distinct polymerization methodologies, Friedel-Crafts knitting using an external crosslinker, Scholl reaction, and solvent knitting, respectively. Further, the dramatic role of reaction temperatures, catalysts, and solvents resulting in well-defined morphologies was elucidated. Mechanistic investigations coupled with microscopic and computational studies revealed the evolution of 2D nanosheets of a highly porous solvent-knitted polymer (SKTP, 2385 m² g^-1), resulting from the sequential hierarchical self-assembly of nanospheres and nanoribbons. A structure-activity correlation of hypercrosslinked polymers and their sulfonated counterparts for the removal of toxic polar organic micropollutants from water was delineated based on the chemical functionalities, specific surface area, pore size distribution, dispersity, and nanoscale morphology. Furthermore, a sulfonated 2D sheet-like solvent-knitted polymer (SKTPS) exhibited rapid adsorption kinetics (within 30 s) for a large array of polar organic micropollutants, including plastic components, steroids, antibiotic drugs, herbicides, and pesticides with remarkable uptake capacity and excellent recyclability. The current study provides the impetus for designing morphology-controlled functionalized porous polymers for task-specific applications.

Impact of Imine Bond Orientations on the Geometric and Electronic Structures of Imine-based Covalent Organic Frameworks

Many efforts are currently devoted to improving the stability and crystallinity of imine-based two-dimensional (2D) covalent organic frameworks (COFs) given their wide range of potential applications. The variation in the relative orientations of the imine bonds has been found to be a critical factor that impacts the stacking of the 2D COF layers, leads to the formation of isomer structures, and influences the crystallinity of the final product. Most investigations to date have focused only on the structural properties, while the role of the imine orientations on the electronic properties has not been studied systematically. Here, we explore this effect by examining how the electronic band structures, electronic couplings, and effective masses evolve when considering four isomeric structures of an imine-linked tetraphenyl-pyrene naphthalene-diimide COF. Our results provide an understanding of the impact of the imine orientations and how they need to be controlled to realize COF inter-layer stackings that can lead to efficient cross-plane electron transport. They can be used to guide the design and synthesis of imine-based COFs for applications where charge transport needs to be optimized.

Role of ultramicropores in the remarkable gas storage in hypercrosslinked polystyrene networks studied by positron annihilation

In this paper, hypercrosslinked polystyrene (HCLPS) networks were synthesized by radical bulk polymerization and Friedel-Crafts alkylation reactions using vinylbenzyl-co-divinylbenzene chloride (VBC-DVB) as the precursors. A series of HCLPS was prepared with varying content of DVB from 0 to 10% in the precursor. Both N2 adsorption and positron annihilation measurements reveal micropores in the HCLPS. Especially, the existence of ultramicropores with a size in the range of 0.63-0.7 nm is confirmed by positron lifetime measurements. With increasing DVB content from 0 to 10%, the number of ultramicropores shows a gradual increase. Both the H2 and CO2 adsorption capacity increase monotonously with the increase of the DVB content. With 10% DVB in the HCLPS, the H2 storage increases to 10.3 mmol g-1 (2.05 wt%) at 77 K and 1 bar and the CO2 capture reaches 2.81 mmol g-1 (12.4 wt%) at 273 K and 1 bar. The remarkable gas storage ability is ascribed to the existence of the ultramicropores, which result in a stronger affinity to the gas molecules. By using positrons as a new probe for the pores, our results provide convincing evidence of the role of ultramicropores in the gas adsorption performance in microporous organic polymers.

Molten Salt Templated Synthesis of Covalent Isocyanurate Frameworks with Tunable Morphology and High CO2 Uptake Capacity

The use of reactive molten salts, i.e., ZnCl₂, as a soft template and a catalyst has been actively investigated in the preparation of covalent triazine frameworks (CTFs). Although the soft templating effect of the salt melt is more prominent at low temperatures, close to the melting point of ZnCl₂, leading to the formation of abundant micropores, a significant mesopore formation is observed that is due to the partial carbonization and other side reactions at higher temperatures (>400 °C). Evidently, high-temperature synthesis of CTFs in various eutectic salt mixtures of ZnCl₂ with alkali metal chloride salts also leads to mesopore formation. We reasoned that using the isocyanate moieties instead of cyano groups in the monomer, 1,4-phenylene isocyanate, could enable efficient interactions between carbonyl moieties and alkali metal ions to realize efficient salt templating to form covalent isocyanurate frameworks (CICFs). In this direction, the trimerization of 1,4-phenylene diisocyanate was carried out under ionothermal conditions at different reaction temperatures using ZnCl₂ (CICF) and the eutectic salt mixture of KCl/NaCl/ZnCl₂ (CICF-KCl/NaCl) as the reactive solvents. We observed notable differences in the morphologies of the two polymers, whereas CICF showed irregular-shaped micrometer-sized particles, the CICF-KCl/NaCl exhibited a filmlike morphology. Moreover, favorable ion-dipole interactions between alkali metal cations and oxygen atoms of the monomer facilitated two-dimensional growth and the formation of a purely microporous framework in the case of CICF-KCl/NaCl along with a near theoretical retention of the nitrogen content at 500 °C. The CICF-KCl/NaCl showed a BET surface area of 590 m² g^-1 along with a CO₂ uptake capacity of 5.9 mmol g^-1 at 273 K and 1.1 bar because of its high microporosity and nitrogen content. On the contrary, in the absence of alkali metal ions, CICF showed high mesopore content and a moderate CO₂ uptake capacity. This study underscores the importance of the strength of the interactions between the salts and the monomer in the ionothermal synthesis to control the morphology, porosity, and gas uptake properties of the porous organic polymers.

Recent advances in porous nanostructures for cancer theranostics

Porous nanomaterials with high surface area, tunable porosity, and large mesopores have recently received particular attention in cancer therapy and imaging. Introduction of additional pores to nanostructures not only endows the tunability of optoelectronic and optical features optimal for tumor treatment, but also modulates the loading capacity and controlled release of therapeutic agents. In recognition, increasing efforts have been made to fabricate various porous nanomaterials and explore their potentials in oncology applications. Thus, a systematic and comprehensive summary is necessary to overview the recent progress, especially in last ten years, on the development of various mesoporous nanomaterials for cancer treatment as theranostic agents. While outlining their individual synthetic mechanisms after a brief introduction of the structures and properties of porous nanomaterials, the current review highlighted the representative applications of three main categories of porous nanostructures (organic, inorganic, and organic-inorganic nanomaterials). In each category, the synthesis, representative examples, and interactions with tumors were further detailed. The review was concluded with deliberations on the key challenges and future outlooks of porous nanostructures in cancer theranostics.

Synthesis methods of microporous organic polymeric adsorbents: a review

MOPs can be synthesized in a large variety of ways, which affect their pores and surface area. Variation in synthesis and porosity has a significant effect on their adsorption properties.

Metal-Assisted and Solvent-Mediated Synthesis of Two-Dimensional Triazine Structures on Gram Scale

Covalent triazine frameworks are an emerging material class that have shown promising performance for a range of applications. In this work, we report on a metal-assisted and solvent-mediated reaction between calcium carbide and cyanuric chloride, as cheap and commercially available precursors, to synthesize two-dimensional triazine structures (2DTSs). The reaction between the solvent, dimethylformamide, and cyanuric chloride was promoted by calcium carbide and resulted in dimethylamino-s-triazine intermediates, which in turn undergo nucleophilic substitutions. This reaction was directed into two dimensions by calcium ions derived from calcium carbide and induced the formation of 2DTSs. The role of calcium ions to direct the two-dimensionality of the final structure was simulated using DFT and further proven by synthesizing molecular intermediates. The water content of the reaction medium was found to be a crucial factor that affected the structure of the products dramatically. While 2DTSs were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs or only graphitic material (GM) was obtained in aqueous solutions. Due to the straightforward and gram-scale synthesis of 2DTSs, as well as their photothermal and photodynamic properties, they are promising materials for a wide range of future applications, including bacteria and virus incapacitation.

A Covalent Organic Framework for Fast-Charge and Durable Rechargeable Mg Storage

High-safety, low-cost, and high-volumetric-capacity rechargeable magnesium batteries (RMBs) are promising alternatives to lithium ion batteries. However, lack of high-power, high-energy, and stable cathodes for RMBs hinders their commercialization. Herein, an environmentally benign, low-cost, and sustainable covalent organic framework (COF) cathode for Mg storage is reported for the first time. It delivers a high power density of 2.8 kW kg^-1, a high specific energy density of 146 Wh kg^-1, and an ultralong cycle life of 3000 cycles with a very slow capacity decay rate of 0.0196% per cycle, representing one of the best cathodes to date. The comprehensive electrochemical analysis proves that triazine ring sites in the COF are redox centers for reversible reaction with magnesium ions, and the ultrafast reaction kinetics are mainly attributed to pseudocapacitive behavior. The high-rate Mg storage of the COF offers new opportunities for the development of ultrastable and fast-charge RMBs.

Effect of Building Block Transformation in Covalent Triazine-Based Frameworks for Enhanced CO2 Uptake and Metal-Free Heterogeneous Catalysis

Covalent triazine frameworks (CTFs) have provided a unique platform in functional material design for a wide range of applications. This work reports a series of new CTFs with two new heteroaromatic building blocks (pyrazole and isoxazole groups) through a building-block transformation approach aiming for carbon capture and storage (CCS) and metal-free catalysis. The CTFs were synthesized from their respective building blocks [(4,4'-(1H-pyrazole-3,5-diyl)dibenzonitrile (pyz) and 4,4'-(isoxazole-3,5-diyl)dibenzonitrile (isox))] under ionothermal conditions using ZnCl₂ . Both of the building blocks were designed by an organic transformation of an acetylacetone containing dinitrile linker to pyrazole and isoxazole groups, respectively. Due to this organic transformation, (i) linker aromatization, (ii) higher surface areas and nitrogen contents, (iii) higher aromaticity, and (iv) higher surface basicity was achieved. Due to these enhanced properties, CTFs were explored for CO₂ uptake and metal-free heterogeneous catalysis. Among all, the isox-CTF, synthesized at 400 °C, showed the highest CO₂ uptake (4.92 mmol g^-1 at 273 K and 2.98 mmol g^-1 at 298 K at 1 bar). Remarkably, these CTFs showed excellent metal-free catalytic activity for the aerobic oxidation of benzylamine at mild reaction conditions. On studying the properties of the CTFs, it was observed that organic transformations and ligand aromatization of the materials are crucial factor to tune the important parameters that influence the CO₂ uptake and the catalytic activity. Overall, this work highlights the substantial effect of designing new CTF materials by building-block organic transformations resulting in better properties for CCS applications and heterogeneous catalysis.

Playing with covalent triazine framework tiles for improved CO2 adsorption properties and catalytic performance

The rational design and synthesis of covalent triazine frameworks (CTFs) from defined dicyano-aryl building blocks or their binary mixtures is of fundamental importance for a judicious tuning of the chemico-physical and morphological properties of this class of porous organic polymers. In fact, their gas adsorption capacity and their performance in a variety of catalytic transformations can be modulated through an appropriate selection of the building blocks. In this contribution, a set of five CTFs (CTF1-5) have been prepared under classical ionothermal conditions from single dicyano-aryl or heteroaryl systems. The as-prepared samples are highly micro-mesoporous and thermally stable materials featuring high specific surface area (up to 1860 m2·g-1) and N content (up to 29.1 wt %). All these features make them highly attractive samples for carbon capture and sequestration (CCS) applications. Indeed, selected polymers from this series rank among the CTFs with the highest CO2 uptake at ambient pressure reported so far in the literature (up to 5.23 and 3.83 mmol·g-1 at 273 and 298 K, respectively). Moreover, following our recent achievements in the field of steam- and oxygen-free dehydrogenation catalysis using CTFs as metal-free catalysts, the new samples with highest N contents have been scrutinized in the process to provide additional insights to their complex structure-activity relationship.

Substantial LIB Anode Performance of Graphitic Carbon Nanoflakes Derived from Biomass Green-Tea Waste

Biomass-derived carbonaceous constituents constitute fascinating green technology for electrochemical energy-storage devices. In light of this, interconnected mesoporous graphitic carbon nanoflakes were synthesized by utilizing waste green-tea powders through the sequential steps of air-assisted carbonization, followed by potassium hydroxide activation and water treatment. Green-tea waste-derived graphitic carbon displays an interconnected network of aggregated mesoporous nanoflakes. When using the mesoporous graphitic carbon nanoflakes as an anode material for the lithium-ion battery, an initial capacity of ~706 mAh/g and a reversible discharge capacity of ~400 mAh/g are achieved. Furthermore, the device sustains a large coulombic efficiency up to 96% during 100 operation cycles under the applied current density of 0.1 A/g. These findings depict that the bio-generated mesoporous graphitic carbon nanoflakes could be effectively utilized as a high-quality anode material in lithium-ion battery devices.

Fast Microwave Synthesis of Hierarchical Porous Carbons from Waste Palm Boosted by Activated Carbons for Supercapacitors

The synthesis of biomass-derived porous carbons (PCs) for supercapacitors by conventional two-steps method (chemical activation after carbonization) is complicated and time-consuming. In this study, we present a one-step microwave activation strategy to prepare hierarchically PCs from waste palm boosted by activated carbons (ACs). ACs with various specific surface areas (14, 642, and 1344 m²·g^-1) were used for the first time to fast absorb microwave energy for converting waste palm into hierarchically PCs, that is, PC1, PC2, and PC3, respectively. The morphological and structural characterizations of PCs were studied. Also, the electrochemical performances of supercapacitors based on PCs as electrodes were further investigated. The results showed that the PC (PC1) boosted by AC with the lowest specific surface area possessed a porous structure (containing micro-, meso-, and macro- pores) with the largest specific surface area (1573 m²·g^-1) and the highest micropore volume (0.573 cm³·g^-1), as well as the suitable mesoporosity (29.69%). The as-prepared PC1 supercapacitor even in a gel electrolyte (PVA/LiCl) exhibited a high specific capacitance of 226.0 F·g^-1 at 0.5 A·g^-1 and presented excellent charge-discharge performance with an energy density of 72.3 Wh·kg^-1 at a power density of 1.4 kW·kg^-1 and 50.0 Wh·kg^-1 at 28.8 kW·kg^-1. Moreover, this promising method exhibited a simple, rapid, and cost-effective preparation of carbon materials from renewable biomass for energy storage applications.

New and Advanced Porous Carbon Materials in Fine Chemical Synthesis. Emerging Precursors of Porous Carbons

The efficiency of porous carbons in fine chemical synthesis, among other application fields, has been demonstrated since both the porous structure and chemical surface provide the appropriated chemical environment favoring a great variety of relevant chemical transformations. In recent years, metal organic frameworks (MOFs) and covalent organic frameworks (COFs) have emerged as interesting opportunities in the preparation of porous carbons with improved physico-chemical properties. Direct calcination of MOFs or COFs, in the presence or not of others carbon or heteroatom sources, could be considered an easy and practical approach for the synthesis of highly dispersed heteroatom-doped porous carbons but also new porous carbons in which single atoms of metallic species are present, showing a great development of the porosity; both characteristics of supreme importance for catalytic applications. The goal of this review is to provide an overview of the traditional methodologies for the synthesis of new porous carbon structures together with emerging ones that use MOFs or COFs as carbon precursors. As mentioned below, the catalytic application in fine chemical synthesis of these kinds of materials is at present barely explored, but probably will expand in the near future.

A highly soluble, crystalline covalent organic framework compatible with device implementation

Covalent organic frameworks (COFs) have emerged as a tailor-made platform for designing next-generation two-dimensional materials. However, COFs are produced as insoluble and unprocessable solids, which precludes the preparation of thin films for optoelectronic applications. Here, we report designed synthesis of a highly soluble yet crystalline COF material through the regulation of its inter-layer interactions. The resulting COF is remarkably soluble in a variety of organic solvents and forms stable true solutions with retention of its layered structure. These unique features endow the COF with solution processability; high-quality, large-area COF films can be produced on various substrates in a high-throughput and efficient manner, with good control over the film thickness, making this material compatible with a variety of device applications. The films are electrically anisotropic; the intra-layer carrier conduction is inhibited, while the inter-layer carrier migration is outstanding, showing the highest conductivity among all reported COF materials. Our highly soluble and processable COF may open new pathways for realising high-performance COF-based optoelectronic devices with diverse functions.

Recent Advancements in the Synthesis of Covalent Triazine Frameworks for Energy and Environmental Applications

Covalent triazine frameworks (CTFs) are a unique type of porous materials, comprised of triazine units. Owing to the strong linkage of triazine, the most important advantage of CTFs lies in their high chemical and thermal stabilities and high nitrogen content as compared to other porous organic polymers (POPs). Therefore, CTFs are one of the most promising materials for practical applications. Much research has been devoted to developing new methods to synthesize CTFs and explore their potential applications. Nowadays, energy and environmental issues have attracted enormous attention. CTFs are particular promising for energy- and environment-related applications, due to their nitrogen-rich scaffold and robust structure. Here, we selected some typical examples and reviewed recent advancements in the synthesis of CTFs and their applications in gas adsorption, separation, and catalysis in relation to environment and energy issues.

Role of Surface Phenolic-OH Groups in N-Rich Porous Organic Polymers for Enhancing the CO2 Uptake and CO2/N2 Selectivity: Experimental and Computational Studies

Design and successful synthesis of phenolic-OH and amine-functionalized porous organic polymers as adsorbent for postcombustion CO₂ uptake from flue gas mixtures along with high CO₂/N₂ selectivity is a very demanding research area in the context of developing a suitable adsorbent to mitigate greenhouse gases. Herein, we report three triazine-based porous organic polymers TrzPOP-1, -2, and -3 through the polycondensation of two triazine rings containing tetraamine and three dialdehydes. These porous organic polymers possess high Brunauer-Emmett-Teller (BET) surface areas of 995, 868, and 772 m² g^-1, respectively. Out of the three materials, TrzPOP-2 and TrzPOP-3 contain additional phenolic-OH groups along with triazine moiety and secondary amine linkages. At 273 K, TrzPOP-1, -2, and -3 displayed CO₂ uptake capacities of 6.19, 7.51, and 8.54 mmol g^-1, respectively, up to 1 bar pressure, which are considerably high among all porous polymers reported till date. Despite the lower BET surface area, TrzPOP-2 and TrzPOP-3 containing phenolic-OH groups showed higher CO₂ uptakes. To understand the CO₂ adsorption mechanism, we have further performed the quantum chemical studies to analyze noncovalent interactions between CO₂ molecules and different polar functionalities present in these porous polymers. TrzPOP-1, -2, and -3 have the capability of selective CO₂ uptake over that of N₂ at 273 K with the selectivity of 61:1, 117:1, and 142:1 by using the initial slope comparing method, along with 108.4, 140.6, and 167.4 by using ideal adsorbed solution theory (IAST) method, respectively. On the other hand, at 298 K, the calculated CO₂/N₂ selectivities in the initial slope comparing method for TrzPOP-1, -2, and -3 are 27:1, 72:1, and 96:1, whereas those using IAST method are 42.1, 75.7, and 94.5, respectively. Cost effective and scalable synthesis of these porous polymeric materials reported herein for selective CO₂ capture has a very promising future for environmental clean-up.

Palladium Supported on an Amphiphilic Triazine-Urea-Functionalized Porous Organic Polymer as a Highly Efficient Electrocatalyst for Electrochemical Sensing of Rutin in Human Plasma

Metal nanoparticle-containing porous organic polymers have gained great interest in chemical and pharmaceutical applications owing to their high reactivity and good recyclability. In the present work, a palladium nanoparticle-decorated triazine-urea-based porous organic polymer (Pd@TU-POP) was designed and synthesized using 1,3-bis(4-aminophenyl)urea with cyanuric chloride and palladium acetate. The porous structure and physicochemical properties of the electrode material Pd@TU-POP were observed using a range of standard techniques. The Pd@TU-POP material on the electrode surface showed superior sensing ability for rutin (RT) because the Pd dispersion facilitated the electrocatalytic performance of TU-POP by reducing the overpotential of RT oxidation dramatically and improving the stability significantly. Furthermore, TU-POP provides excellent structural features for loading Pd nanoparticles, and the resulting Pd@TU-POP exhibited enhanced electron transfer and outstanding sensing capability in a linear range between 2 and 200 pM having a low detection value of 5.92 × 10^-12 M (S/N = 3). The abundant porous structure of Pd@TU-POP not only provides electron transport channels for RT diffusion but also offers a facile route for quantification sensing of RT with satisfactory recoveries in aqueous electrolyte containing human plasma and red wine. These data reveal that the synthetic Pd@TU-POP is an excellent potential platform for the detection of RT in biological samples.

Rational Design of Porous Covalent Triazine-Based Framework Composites as Advanced Organic Lithium-Ion Battery Cathodes

In an effort to explore the use of organic high-performance lithium ion battery cathodes as an alternative to resolve the current bottleneck hampering the development of their inorganic counterparts, a rational strategy focusing on the optimal composition of covalent triazine-based frameworks (CTFs) with carbon-based materials of varied dimensionalities is delineated. Two-dimensional reduced graphene oxide (rGO) with a compatible structural conformation with the layered CTF is the most suitable scaffold for the tailored mesopores in the polymeric framework, providing outstanding energy storage ability. Through facile ionothermal synthesis and structure engineering, the obtained CTF-rGO composite possesses a high specific surface area of 1357.27 m²/g, and when used as a lithium ion battery cathode it delivers a large capacity of 235 mAh/g in 80 cycles at 0.1 A/g along with a stable capacity of 127 mAh/g over 2500 cycles at 5 A/g. The composite with modified pore structure shows drastically improved performance compared to a pristine CTF, especially at large discharge currents. The CTF-rGO composite with excellent capacity, stability, and rate performance shows great promise as an emerging high-performance cathode that could revolutionize the conventional lithium-ion battery industry.

Recent advances in functionalized micro and mesoporous carbon materials: synthesis and applications

Functionalized nanoporous carbon materials have attracted the colossal interest of the materials science fraternity owing to their intriguing physical and chemical properties including a well-ordered porous structure, exemplary high specific surface areas, electronic and ionic conductivity, excellent accessibility to active sites, and enhanced mass transport and diffusion. These properties make them a special and unique choice for various applications in divergent fields such as energy storage batteries, supercapacitors, energy conversion fuel cells, adsorption/separation of bulky molecules, heterogeneous catalysts, catalyst supports, photocatalysis, carbon capture, gas storage, biomolecule detection, vapour sensing and drug delivery. Because of the anisotropic and synergistic effects arising from the heteroatom doping at the nanoscale, these novel materials show high potential especially in electrochemical applications such as batteries, supercapacitors and electrocatalysts for fuel cell applications and water electrolysis. In order to gain the optimal benefit, it is necessary to implement tailor made functionalities in the porous carbon surfaces as well as in the carbon skeleton through the comprehensive experimentation. These most appealing nanoporous carbon materials can be synthesized through the carbonization of high carbon containing molecular precursors by using soft or hard templating or non-templating pathways. This review encompasses the approaches and the wide range of methodologies that have been employed over the last five years in the preparation and functionalisation of nanoporous carbon materials via incorporation of metals, non-metal heteroatoms, multiple heteroatoms, and various surface functional groups that mostly dictate their place in a wide range of practical applications.

Creation and bioapplications of porous organic polymer materials

Emerging porous organic polymers can serve as promising platforms for bio-related applications.