A Comprehensive Review of MXene-Based Emerging Materials for Energy Storage Applications and Future perspectives.

MXenes is a rapidly emerging class of two-dimensional (2D) materials. It exhibits unique properties that make it suitable for a wide range of applications. This review provides a comprehensive overview of the synthesis and processing techniques for MXenes including both bottom-up and top-down approaches.

Iron Sulfide Microspheres Supported on Cellulose-Carbon Nanotube Conductive Flexible Film as an Electrode Material for Aqueous-Based Symmetric Supercapacitors with High Voltage.

Nanostructured iron disulfide (FeS) was uniformly deposited on regenerated cellulose (RC) and oxidized carbon nanotube (CNT)-based composite films using a simple chemical bath deposition method to form RC/CNT/FeS composite films. The RC/CNT composite film served as an ideal substrate for the homogeneous deposition of FeS microspheres due to its unique porous architecture, large specific surface area, and high conductivity. Polypyrrole (PPy), a conductive polymer, was coated on the RC/CNT/FeS composite to improve its conductivity and cycling stability.

Covalent-Organic-Framework-Modified Quartz Crystal Microbalance Sensor for Selective Detection of Hazardous Formic Acid.

Covalent organic frameworks (COFs) are a novel family of porous crystalline materials utilized in various advanced applications. However, applying COFs as a hazardous organic acid gas sensor is substantial but still challenging. Herein, a phenylenediamine-based covalent organic framework (TPDA-TPB COF) featuring excellent crystallinity, ultrastable thermal stability, and high surface area was successfully constructed.

Room-Temperature Synthesis of Covalent Organic Frameworks using Gamma-Irradiation in Open-Air Conditions.

Covalent organic frameworks (COFs), which have layered stacking structures, extended π-conjugation, and periodic frameworks have become a promising class of materials for a wide range of applications. However, their synthetic pathways frequently need high temperatures, enclosed systems under high pressures, an inert atmosphere, and extended reaction time, which restrict their practicality in real-world applications. Herein, the use of gamma irradiation is presented to synthesize highly crystalline COFs at room temperature under an open-air condition within a short time.

Designing of covalent organic framework/2D g-CN heterostructure using a simple method for enhanced photocatalytic hydrogen production.

Designing heterostructure photocatalysts is a promising approach for developing highly efficient photocatalysts for hydrogen energy production. In this work, we synthesized a series of a covalent organic framework (COF)/g-CN (CN) heterojunction photocatalysts, denoted as x % COF/CN (in which x indicates the weight % of COF and x  = 5, 10, 20, 30, 40, 50, 90, 95, 100), for hydrogen production. The COF, which is a key component of the photocatalyst, was prepared by assembling benzothiadiazole (BT) and pyrene (Py) derivatives as building blocks.

π-Electron-Extended Triazine-Based Covalent Organic Framework as Photocatalyst for Organic Pollution Degradation and H Production from Water.

Herein, we report the efficient preparation of π-electron-extended triazine-based covalent organic framework (TFP-TPTPh COF) for photocatalysis and adsorption of the rhodamine B (RhB) dye molecule, as well as for photocatalytic hydrogen generation from water. The resultant TFP-TPTPh COF exhibited remarkable porosity, excellent crystallinity, high surface area of 724 m g, and massive thermal stability with a char yield of 63.41%.

Design and synthesis of metal-free ethene-based covalent organic framework photocatalysts for efficient, selective, and long-term stable CO conversion into methane.

The efficient and selective photocatalytic CO conversion into higher-valued hydrocarbon products (e.g., methane and ethane) over covalent organic frameworks (COFs) remains a challenge, with all previously reported attempts producing carbon monoxide as the dominant product.

Effective remediation of Pb polluted environment by adsorption onto recyclable hydroxyl bearing covalent organic framework.

The removal of heavy metal ions from wastewater has attracted considerable interest because of their toxicity. Adsorption is one of the most promising methods for the removal of heavy metal ions due to its simplicity and effectiveness. Recently, covalent organic frameworks (COFs) have become promising adsorbents for effective wastewater remediation.

High Thermal Resistance of Epoxy/Cyanate Ester Hybrids Incorporating an Inorganic Double-Decker-Shaped Polyhedral Silsesquioxane Nanomaterial.

In this study, we prepared a difunctionalized cyanate ester double-decker silsesquioxane (DDSQ-OCN) cage with a char yield and thermal decomposition temperature () which were both much higher than those of a typical bisphenol A dicyanate ester (BADCy, without the DDSQ cage) after thermal polymerization. Here, the inorganic DDSQ nanomaterial improved the thermal behavior through a nano-reinforcement effect. Blending the inorganic DDSQ-OCN cage into the epoxy resin improved its thermal and mechanical stabilities after the ring-opening polymerization of the epoxy units during thermal polymerization.

Hydroxyl-Functionalized Covalent Organic Frameworks as High-Performance Supercapacitors.

Covalent organic frameworks (COFs) have attracted significant interest because of their heteroatom-containing architectures, high porous networks, large surface areas, and capacity to include redox-active units, which can provide good electrochemical efficiency in energy applications. In this research, we synthesized two novel hydroxy-functionalized COFs-TAPT-2,3-NA(OH) TAPT-2,6-NA(OH) COFs-through Schiff-base [3 + 2] polycondensations of 1,3,5-tris-(4-aminophenyl)triazine (TAPT-3NH) with 2,3-dihydroxynaphthalene-1,4-dicarbaldehyde (2,3-NADC) and 2,6-dihydroxynaphthalene-1,5-dicarbaldehyde (2,6-NADC), respectively. The resultant hydroxy-functionalized COFs featured high BET-specific surface areas up to 1089 m g, excellent crystallinity, and superior thermal stability up to 60.

Metal Complexes of the Porphyrin-Functionalized Polybenzoxazine.

New porphyrin-functionalized benzoxazine (Por-BZ) in high purity and yield was synthesized in this study based on H and C NMR and FTIR spectroscopic analyses through the reduction of Schiff base formed from tetrakis(4-aminophenyl)porphyrin (TAPP) and salicylaldehyde and the subsequent reaction with CHO. Thermal properties of the product formed through ring-opening polymerization (ROP) of Por-BZ were measured using DSC, TGA and FTIR spectroscopy. Because of the rigid structure of the porphyrin moiety appended to the benzoxazine unit, the temperature required for ROP (314 °C) was higher than the typical Pa-type benzoxazine monomer (ca.

Carbazole- and thiophene-containing conjugated microporous polymers with different planarity for enhanced photocatalytic hydrogen evolution.

We report the synthesis of two carbazole-thiophene-based conjugated microporous polymers (Cz-3Th and Cz-4Th CMPs) with different degrees of planarity for photocatalytic hydrogen evolution from water. Depending upon the building linker's planarity, we found that the porous structure, hydrogen-evolution rate, and photocatalytic stability of the resultant CMPs varied.

One-Pot Synthesis of Some New -Triazole Derivatives and Their Potential Application for Water Decontamination.

A rapid, efficient, and one-pot protocol has been developed for the synthesis of cyclized 2,6-dimethyl-5-substituted-thiazolo[3,2-]--triazoles () through the interaction of 5-methyl-1--triazole-3-thiol () with aliphatic ketones () in refluxing acetic acid in the presence of a catalytic amount of sulfuric acid (AcOH/H) while with aromatic ketones (), a mixture of uncyclized 3-methyl--triazolylthioacetophenone derivatives () and cyclized 6-aryl-2-methyl-thiazolo[3,2-]--triazoles () has been produced. With this catalytic system, inexpensive sulfuric acid was utilized as a catalyst, which prevented the production of poisonous and irritating halo carbonyl compounds. On the other hand, the interaction of -triazole with cyano compounds () afforded the corresponding 6-amino-2-methyl-5-substituted-thiazolo[3,2-]--triazoles ().

High-Performance Supercapacitor Electrodes Prepared From Dispersions of Tetrabenzonaphthalene-Based Conjugated Microporous Polymers and Carbon Nanotubes.

In this study, we prepared a series of conjugated microporous polymers (CMPs) through Sonogashira-Hagihara cross-couplings of a tetrabenzonaphthalene (TBN) monomer with pyrene (Py), tetraphenylethylene (TPE), and carbazole (Car) units and examined their chemical structures, thermal stabilities, morphologies, crystallinities, and porosities. TBN-TPE-CMP possessed a high surface area (1150 m g) and thermal stability ( = 505 °C; char yield = 68 wt %) superior to those of TBN-Py-CMP and TBN-Car-CMP. To improve the conductivity of the TBN-CMP materials, we blended them with highly conductive single-walled carbon nanotubes (SWCNTs).

A Tröger's Base-Derived Covalent Organic Polymer Containing Carbazole Units as a High-Performance Supercapacitor.

Porous organic polymers have been received considerable attention due to their heteroatom-containing structures and high surface areas, which can offer high electrochemical performance in energy applications. The majority of reported Tröger's base-functionalized porous organic polymers have been applied as effective candidates for sensing and gas separation/adsorption, while their use as electrode materials in supercapacitors is rare. Here, a novel covalent microporous organic polymer containing carbazole and Tröger's base CzT-CMOP has been successfully synthesized through the one-pot polycondensation of 9-(4-aminophenyl)-carbazole-3,6-diamine (Cz-3NH) with dimethoxymethane.

Multifunctional Hypercrosslinked Porous Organic Polymers Based on Tetraphenylethene and Triphenylamine Derivatives for High-Performance Dye Adsorption and Supercapacitor.

We successfully prepared two different classes of hypercrosslinked porous organic polymers (HPPs)-the tetraphenylethene (TPE) and (4-(5,6-Diphenyl-1H-Benzimidazol-2-yl)-triphenylamine (DPT) HPPs-through the Friedel-Crafts polymerization of tetraphenylethene and 4-(5,6-diphenyl-1H-benzimidazol-2-yl)-triphenylamine, respectively, with 1,4-bis(chloromethyl)benzene (Ph-2Cl) in the presence of anhydrous FeCl as a catalyst. Our porous materials exhibited high BET surface areas (up to 1000 m g) and good thermal stabilities. According to electrochemical and dyes adsorption applications, the as-prepared DPT-HPP exhibited a high specific capacitance of 110 F g at a current density of 0.

High-Molecular-Weight PLA--PEO--PLA Triblock Copolymer Templated Large Mesoporous Carbons for Supercapacitors and CO Capture.

High-molecular-weight PLA--PEO--PLA (LEL) triblock copolymer was synthesized through simple ring-opening polymerization (ROP) by using the commercial homopolymer HO-PEO-OH as the macro-initiator. The material acted as a single template to prepare the large mesoporous carbons by using resol-type phenolic resin as a carbon source. Self-assembled structures of phenolic/LEL blends mediated by hydrogen bonding interaction were determined by FTIR and SAXS analyses.

Synthesis of Schiff and Mannich bases of new -triazole derivatives and their potential applications for removal of heavy metals from aqueous solution and as antimicrobial agents.

An efficient, simple, and one-pot double Mannich reaction was performed for the synthesis of cyclized 2-methyl-6-substituted-6,7-dihydro-5-triazolo[5,1-]-1,3,5-thiadiazines a reaction of 5-methyl-1-triazole-3-thiol (1) with formaldehyde and primary aliphatic amines in ethanol at room temperature, while with primary aromatic amines, uncyclized 3-methyl-1-((substituted-amino)methyl)-1-triazole-5-thiols were produced. Under Mannich reaction conditions, 4-amino-3-methyl--triazole-5-thiol (8) reacted with formaldehyde only in boiling ethanol or at room temperature to afford 3-methyl-5,6-dihydro--triazolo[3,4-]-1,3,4-thiadiazole without incorporation of secondary amine. Furthermore, after reaction of compound 8 with aromatic aldehydes under different reaction conditions, uncyclized Schiff's bases were produced.

Direct synthesis of nitrogen-doped mesoporous carbons from triazine-functionalized resol for CO uptake and highly efficient removal of dyes.

In this study we synthesized a triazine-formaldehyde phenolic resin as a nitrogen-containing resol (N-resol) through the condensation of 2,4,6-tris(4-hydroxyphenyl)triazine and formaldehyde. We then used this N-resol as a carbon and nitrogen atom source, mixing it with a diblock copolymer of PEO-b-PCL as the soft template, for the direct synthesis of N-doped mesoporous carbons. Interestingly, the self-assembled N-resol/PEO-b-PCL blends underwent a mesophase transition from cylinder to gyroid and back again to cylinder structures upon increasing the N-resol concentration (i.

Direct Synthesis of Microporous Bicarbazole-Based Covalent Triazine Frameworks for High-Performance Energy Storage and Carbon Dioxide Uptake.

In this study a series of bicarbazole-based covalent triazine frameworks (Car-CTFs) were synthesized under ionothermal conditions from [9,9'-bicarbazole]-3,3',6,6'-tetracarbonitrile (Car-4CN) in the presence of molten zinc chloride. Thermogravimetric and Brunauer-Emmett-Teller analyses revealed that these Car-CTFs possessed excellent thermal stabilities and high specific surface areas (ca. 1400 m /g).

Ultrastable tetraphenyl-p-phenylenediamine-based covalent organic frameworks as platforms for high-performance electrochemical supercapacitors.

In this study we synthesized two tetraphenyl-p-phenylenediamine-based covalent organic frameworks (TPPDA-TPPyr and TPPDA-TPTPE COFs) for potential use in high-performance electrochemical supercapacitors. This excellent performance arose from their structures containing redox-active triphenylamine derivatives and their high surface areas.

A Convenient One-Pot and Rapid Microwave-Assisted Synthesis of Biologically Active -Triazolo[3,4-b][1,3,4]Thiadiazine and -Triazolo[3,4-b][1,3,4]Thiadiazole Nanoarchitectonics.

A rapid and efficient one-pot protocol has been developed for the synthesis of s-triazolo[3,4-b][1,3,4]thiadiazine and s-triazolo[3,4-b][1,3,4]thiadiazole nanoarchitectonics through the reaction of s-triazoles with ketones and nitriles in acetic acid containing a catalytic amount of sulfuric acid under microwave irradiation in excellent yields. With this catalytic reaction, the cheap sulfuric acid as well as other acids were examined as catalysts and the highly toxic and irritating haloketones and halonitriles were avoided to form. The effects of microwave power, temperature, time, solvent and catalyst were examined.

A Hollow Microtubular Triazine- and Benzobisoxazole-Based Covalent Organic Framework Presenting Sponge-Like Shells That Functions as a High-Performance Supercapacitor.

In this paper we report the construction of a hollow microtubular triazine- and benzobisoxazole-based covalent organic framework (COF) presenting a sponge-like shell through a template-free [3+2] condensation of the planar molecules 2,4,6-tris(4-formylphenyl)triazine (TPT-3CHO) and 2,5-diaminohydroquinone dihydrochloride (DAHQ-2HCl). The synthesized COF exhibited extremely high crystallinity, a high surface area (ca. 1855 m  g ), and ultrahigh thermal stability.

Hollow Microspherical and Microtubular [3 + 3] Carbazole-Based Covalent Organic Frameworks and Their Gas and Energy Storage Applications.

Covalent organic frameworks (COFs) are a family of crystalline porous networks having applications in various fields, including gas and energy storage. Despite respectable progress in the synthesis of such crystalline materials, examples of the use of template-free methods to construct COFs having hollow nano- and microstructures are rare. Furthermore, all reported methods for synthesizing these hollow structural COFs have involved [4 + 2] and [3 + 2] condensations.