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Lithium–sulfur (Li–S) batteries are among the most promising new-generation energy storage devices due to their abundant reserves, low price, and high theoretical specific capacity (1675 mA h g−1). However, Li–S batteries still face challenges such as the "shuttle effect" and slow redox kinetic reactions during charging and discharging. Here, we report a covalent organic skeleton with a bisulfite (EB-COF:HSO3) modified separator, which is capable of mitigating the shuttle effect of polysulfide anions and accelerating Li–S transport. Specifically, negatively charged sulfate groups can inhibit identically charged polysulfide anions through electrostatic repulsion, thereby improving the cycling stability of the battery. At the same time, positively charged lithium ions are promoted to pass through the separator. As a result, the EB-COF:HSO3-modified separator exhibited excellent electrochemical performance at a current density of 1C, with an initial specific capacity of 968 mA h g−1, and maintained a capacity of 785 mA h g−1 after 500 cycles with a decay rate of only 0.04%. In comparison, EB-COF under the same conditions has an initial capacity of 813 mA h g−1 and a high decay rate of 0.12%. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) containing S heteroatom are promising materials for applications in photocatalysis due to their donor–acceptor-type structures, which can improve the mobility of carriers in polymers. Herein, a series of composites (TTBT-COF@PEGx, x = 10, 20, and 30) were prepared based on CTF containing S heteroatom and polyethylene glycol (PEG) by a two-step reaction. The results show that the photocatalytic hydrogen evolution rate of TTBT-COF@PEG30 is 1.51 times that of pristine TTBT-COF. This significant improvement was attributed to PEG in the pores, which resulted in a stable layered structure, reuced distortion and deformation of the skeleton, and rapid separation and transportation of photogenerated electron holes. [ABSTRACT FROM AUTHOR]

Herein, a covalent organic framework (SO3-COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO3-COF@Al2O3. The experimental results show that SO3-COF@Al2O3 can effectively inhibit the shuttle effect of soluble lithium polysulfide (LiPSs) in LSBs after loading the active material sulfur, and exhibits better cycling behavior than the initial polymer SO3-COF. The initial discharge specific capacity of this electrode material at 0.05C is as high as 1141 mA h g−1, and the capacity can be maintained at 466 mA h g−1 after 500 cycles with a capacity decay rate of 0.08% per cycle. [ABSTRACT FROM AUTHOR]

Currently, the preparation of high-performance electrode materials is urgently needed for supercapacitors. As a new kind of organic porous material, covalent organic frameworks (COFs) with an ordered pore structure, a high specific surface area and designability, have shown great potential application value as electrode materials for supercapacitors. However, their potential application in supercapacitors is limited by the poor conductivity of COFs. Here, we in situ grew the highly crystalline triazine-based covalent organic framework DHTA-COF on a modified -Al2O3 substrate to obtain the composites Al2O3@DHTA-COFs. Some of the obtained Al2O3@DHTA-COF composites can maintain some degree of crystallinity, good stability and a vesicular structure. Compared to the precursors -Al2O3 and DHTA-COF, the 50%Al2O3@DHTA-COF composite has superior electrochemical properties as electrode materials for supercapacitors. Under the same conditions, the specific capacitance values of 50%Al2O3@DHTA-COF (261.5 F g−1 at 0.5 A g−1) are 6.2 and 9.6 times higher than the values of DHTA-COF and -Al2O3–CHO, respectively. Additionally, the 50%Al2O3@DHTA-COF electrode material exhibited long-term cycling stability even after 6000 charge–discharge cycles. The study can provide some reference for the development of COF-based composite materials for energy storage. [ABSTRACT FROM AUTHOR]

Covalent triazine frameworks (CTFs) are considered as ideal potential cathode composites for anchoring lithium sulfide compounds. In this paper, five fluorine-containing CTF materials (FN-CTFs) were successfully prepared by modulating the molar ratio of the feeding monomers TFTN and DCB. During the experiment, the optimal content of sulfur was determined to be 71.92% (mass fraction) by adjusting the sulfur content. The initial discharge capacity of the composite electrode at a rate of 0.5C is 959.5 mA h g−1, and after 200 charge–discharge cycles, the residual rate of discharge capacity is 71.32%, and the discharge capacity is 684.3 mA h g−1. Sulfur utilization, cycling stability and multiplier performance of the SFN-CTF composite cathodes are all superior to those of sulfur cathodes. [ABSTRACT FROM AUTHOR]

As a rising class of crystallographic organic polymers, covalent-organic frameworks (COFs) have high specific surface areas, ordered pore structures, and designability, which exhibit broad application prospects in the energy storage sector. However, their low electrical conductivity hinders their potential use in supercapacitors. To improve the electrical conductivity, we introduced carboxylated multi-walled carbon nanotubes to obtain a series of carbon nanotube@COF composites by a facile one-pot method, in which 2D TFA-COFs are in situ grown on the surface of carboxylated multi-walled carbon nanotubes. Among them, the CNT@TFA-COF-3 composite exhibits good crystallinity, regular pores, excellent stability and a specific surface area of 1034 m2 g−1. As expected, as a capacitive electrode material, the CNT@TFA-COF composite shows improved electrochemical performance. Notably, the value of specific capacitance of the CNT@TFA-COF-3 composite (338 F g−1) is about 8.5, 4.9, and 7.5 times higher than those of TFA-COFs, CNTs, and the CNT/TFA-COF physically mixed complex at a current density of 1.0 A g−1, respectively. Furthermore, the CNT@TFA-COF-3 supercapacitor exhibits long-term cycle chemical stability and splendid rate capability even after 7000 charge–discharge cycles. The successful preparation of the CNT@TFA-COF-3 composite can provide new ideas for the construction of new COF-based composites and the development of new materials for energy storage. [ABSTRACT FROM AUTHOR]

By selecting the building blocks with different active sites, 4-formylphenylboronic acid (FBA), 3,3′,5,5′-tetrabromo-2,2′-benzothiophene (DDT) and N,N′,N′′,N′′′-tetra(p-phenylene)para-phenylenediamine (TABD), two conjugated microporous polymers (CMPs), SNCMP-1 and SNCMP-2, with multiple active sites were synthesized via a palladium(II)-catalyzed coupling reaction. They exhibited excellent performances in volatile iodine capture with iodine adsorption values of 570 and 698 wt%, respectively. In addition, SNCMP-1 and SNCMP-2 displayed outstanding CO2 adsorption capacities with uptakes up to 3894 and 3878 mg g−1 at 70 bar and 323 K conditions, respectively. [ABSTRACT FROM AUTHOR]

We present three novel conjugated microporous polymers (CMP@1–3), which were formed by an imidization reaction between tetra-(4-aminophenyl)ethylene and anhydrides. These CMPs exhibited high CO2 and organic vapor capture capacity. [ABSTRACT FROM AUTHOR]

Herein we present a rational strategy for the design of a porous organic structure based on conjugated microporous polymers (CMPs), aiming for the super absorption of CO2. The porous skeleton netted with thiophene- and carbazole- polar building blocks exhibits a synergistic effect on the absorption of CO2; the polar moiety facilitates the interaction between CO2 and the porous materials, and the high surface area provides a large interface. Among them, the task specific copolymer SN@CMP-6, exhibits a superior CO2 uptake at 1.05 bar and 273 K (86.46 cm3 g−1). All of the copolymers show high isosteric heats of CO2 adsorption (38.6–59.8 kJ mol−1). [ABSTRACT FROM AUTHOR]

A series of Zn–porphyrin dyes with different donor and π-linker groups based on the dye SM315 were systematically investigated to screen highly efficient candidates based on density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. Compared with SM315, dye 1 not only has stronger and broader absorption spectra and larger intramolecular charge transition (ICT) parameters, but also has a larger maximum short circuit density (JmaxSC) and an open-circuit photovoltage (VOC) due to the insertion of polyoxometalate (POM). In addition, dye 3 with an electron donor 3-ethynyl-7-(4-methoxyphenyl)-10-methyl-10,10a-dihydro-4aH-phenothiazine (D3) exhibits better photovoltaic performance among dyes 1–3 due to its broadest absorption spectra and largest JmaxSC, hence, D3 can act as a promising donor candidate for the construction of efficient dyes. Furthermore, the performance can be further improved by replacing the π-linker 2,1,3-benzothiadiazole (dye 3) with benzo[1,2-b:4,5-b′]difuran-2,6-dione (dye 4) and pyrrolo[2,3-f]indole-2,6(1H,5H)-dione (dye 5). Compared with dye 3, dyes 4 and 5 possess broader absorption spectra and light harvesting efficiency curves, larger ICT parameters, JmaxSC and conduction band energy shift. In particular, dye 4 might obtain a larger short-circuit photocurrent density, and dye 5 might obtain a larger VOC. [ABSTRACT FROM AUTHOR]

A series of conjugated microporous polymers (CMPs) have been synthesized based on zinc–porphyrin building blocks. Azide groups incorporated within the pores of the CMPs were subjected to alkyne click conditions via a facile, one-step quantitative procedure, the resultant porous frameworks exhibited enhanced CO2 sorption properties. [ABSTRACT FROM AUTHOR]

Conjugated microporous polymers (CMPs) are a class of organic porous polymers that combine π-conjugated skeletons with permanent nanopores, in sharp contrast to other porous materials that are not π-conjugated and with conventional conjugated polymers that are nonporous. As an emerging material platform, CMPs offer a high flexibility for the molecular design of conjugated skeletons and nanopores. Various chemical reactions, building blocks and synthetic methods have been developed and a broad variety of CMPs with different structures and specific properties have been synthesized, driving the rapid growth of the field. CMPs are unique in that they allow the complementary utilization of π-conjugated skeletons and nanopores for functional exploration; they have shown great potential for challenging energy and environmental issues, as exemplified by their excellent performance in gas adsorption, heterogeneous catalysis, light emitting, light harvesting and electrical energy storage. This review describes the molecular design principles of CMPs, advancements in synthetic and structural studies and the frontiers of functional exploration and potential applications. [ABSTRACT FROM AUTHOR]

Conjugated microporous polymers exhibit a synergistic structural effect on the exceptional uptake of amines, whereas the dense porphyrin units facilitate uptake, the high porosity offers a large interface and the swellability boosts capacity. They are efficient in the uptake of both vapor and liquid amines, are applicable to various types of amines, and are excellent for cycle use. [ABSTRACT FROM AUTHOR]

A core–shell strategy is demonstrated for designing a conjugated microporous polymer that allows the tuning of light emission over a wide wavelength range in a controlled manner. The polymers not only emit efficiently with an eight-fold enhanced luminescence but also sustain light emissions, irrespective of solvent and state. [ABSTRACT FROM AUTHOR]

Herein, a covalent organic framework (SO 3 -COF) containing sulfonic acid groups has been developed on the surface of alumina by a one-step method, labeled as SO 3 -COF@Al 2 O 3 . The experimental results show that SO 3 -COF@Al 2 O 3 can effectively inhibit the shuttle effect of soluble lithium polysulfide (LiPSs) in LSBs after loading the active material sulfur, and exhibits better cycling behavior than the initial polymer SO 3 -COF. The initial discharge specific capacity of this electrode material at 0.05C is as high as 1141 mA h g -1 , and the capacity can be maintained at 466 mA h g -1 after 500 cycles with a capacity decay rate of 0.08% per cycle.

Currently, the preparation of high-performance electrode materials is urgently needed for supercapacitors. As a new kind of organic porous material, covalent organic frameworks (COFs) with an ordered pore structure, a high specific surface area and designability, have shown great potential application value as electrode materials for supercapacitors. However, their potential application in supercapacitors is limited by the poor conductivity of COFs. Here, we in situ grew the highly crystalline triazine-based covalent organic framework DHTA-COF on a modified θ-Al 2 O 3 substrate to obtain the composites Al 2 O 3 @DHTA-COFs. Some of the obtained Al 2 O 3 @DHTA-COF composites can maintain some degree of crystallinity, good stability and a vesicular structure. Compared to the precursors θ-Al 2 O 3 and DHTA-COF, the 50%Al 2 O 3 @DHTA-COF composite has superior electrochemical properties as electrode materials for supercapacitors. Under the same conditions, the specific capacitance values of 50%Al 2 O 3 @DHTA-COF (261.5 F g -1 at 0.5 A g -1 ) are 6.2 and 9.6 times higher than the values of DHTA-COF and θ-Al 2 O 3 -CHO, respectively. Additionally, the 50%Al 2 O 3 @DHTA-COF electrode material exhibited long-term cycling stability even after 6000 charge-discharge cycles. The study can provide some reference for the development of COF-based composite materials for energy storage.

As a rising class of crystallographic organic polymers, covalent-organic frameworks (COFs) have high specific surface areas, ordered pore structures, and designability, which exhibit broad application prospects in the energy storage sector. However, their low electrical conductivity hinders their potential use in supercapacitors. To improve the electrical conductivity, we introduced carboxylated multi-walled carbon nanotubes to obtain a series of carbon nanotube@COF composites by a facile one-pot method, in which 2D TFA-COFs are in situ grown on the surface of carboxylated multi-walled carbon nanotubes. Among them, the CNT@TFA-COF-3 composite exhibits good crystallinity, regular pores, excellent stability and a specific surface area of 1034 m 2 g -1 . As expected, as a capacitive electrode material, the CNT@TFA-COF composite shows improved electrochemical performance. Notably, the value of specific capacitance of the CNT@TFA-COF-3 composite (338 F g -1 ) is about 8.5, 4.9, and 7.5 times higher than those of TFA-COFs, CNTs, and the CNT/TFA-COF physically mixed complex at a current density of 1.0 A g -1 , respectively. Furthermore, the CNT@TFA-COF-3 supercapacitor exhibits long-term cycle chemical stability and splendid rate capability even after 7000 charge-discharge cycles. The successful preparation of the CNT@TFA-COF-3 composite can provide new ideas for the construction of new COF-based composites and the development of new materials for energy storage.

A new luminescent Eu III complex, namely [Eu 2 (BTFA) 4 (OMe) 2 (dpq) 2 ] (1), in which BTFA = 3-benzoyl-1,1,1-trifluoroacetone and dpq = dipyrido [3,2- d :2',3'- f ] quinoxaline, has been designed and synthesized by employing two different ligands as sensitizers. Crystal structure analysis reveals that complex 1 is composed of dinuclear Eu III units crystallized in the monoclinic P 1̄ space group. Notably, 1 exhibits high thermal stability up to 270 °C and excellent water stability. The photoluminescence property of the complex is investigated. Further studies show 1 can recognize Fe 3+ ions with high selectivity from mixed metal ions in aqueous solution through the luminescence quenching phenomenon. Furthermore, the recyclability and stability of 1 after sensing experiments are observed to be adequate. By virtue of the superior stability, detection efficiency, applicability and reusability, the as-prepared Eu III complex can be a promising fluorescent material for practical sensing., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

A series of conjugated microporous polymers (CMPs) have been synthesized based on zinc-porphyrin building blocks. Azide groups incorporated within the pores of the CMPs were subjected to alkyne click conditions via a facile, one-step quantitative procedure, the resultant porous frameworks exhibited enhanced CO 2 sorption properties.

We report structural insights into the functional origin of conjugated microporous polymers (CMPs), by elucidating the vital role of linkage geometry in controlling the porosity, gas adsorption, conjugation, exciton transport and luminescence. This unprecedented yet crucial role of geometry constitutes a general principle for the rational design of CMPs.

Conjugated microporous polymers exhibit a synergistic structural effect on the exceptional uptake of amines, whereas the dense porphyrin units facilitate uptake, the high porosity offers a large interface and the swellability boosts capacity. They are efficient in the uptake of both vapor and liquid amines, are applicable to various types of amines, and are excellent for cycle use.

A horseradish peroxidase (HRP) biosensor based on alumina (Al(2)O(3)) nanoparticles-chitosan (CHIT) nanocomposites was developed for the detection of phenolic compounds. UV-Vis spectra and Fourier transform infrared spectra showed that HRP retained its original structure on the Al(2)O(3)/CHIT film. The surface morphologies of the composite films were characterized by scanning electron microscopy. Cyclic voltammetry and amperometry were used to study the proposed electrochemical biosensor. Optimization of the experimental parameters was performed with regard to pH, applied electrode potential and the concentration of hydrogen peroxide. The linear range, sensitivity and detection limit of the biosensor were investigated for eight phenolic compounds. In particular, the linearity of the biosensor for the detection of hydroquinone was obtained from 5 × 10(-9) M to 7 × 10(-5) M with a detection limit of 1 nM (based on the S/N = 3). The optimized biosensor for hydroquinone determination displayed a high sensitivity of 518.4 nA μM(-1) with a response time of ∼5 s.