Singlet oxygen (1O2) is of great interest because of its potential applications in photodynamic therapy, photooxidation of toxic molecules, and photochemical synthesis. Herein, we report novel ...metallophthalocyanine (MPc) based conjugated microporous polymers (MPc‐CMPs) as photosensitizers for the generation of 1O2. The rigid microporous structure efficiently improves the exposure of the majority of the MPc units to oxygen. The MPc‐CMPs also exhibit an enhanced light‐harvesting capability in the far‐red region through their extended π‐conjugation systems. Their microporous structure and excellent absorption capability for long‐wavelength photons result in the MPc‐CMPs showing high efficiency for 1O2 generation upon irradiation with 700 nm light, as evident by using 1,3‐diphenylisobenzofuran as an 1O2 trap. These results indicate that MPc‐CMPs can be considered as promising photosensitizers for the generation of 1O2.
In the red: The extended π‐conjugation systems of metallophthalocyanine‐based conjugated microporous polymers (MPc‐CMPs) results in an enhanced light‐harvesting capability in the far‐red region. The microporous structure of the MPc‐CMPs and their excellent absorption capability for long‐wavelength photons, result in them (especially ZnPc‐CMP and CuPc‐CMP) being promising photosensitizers with a high efficiency for 1O2 generation.
Polycarbazoles with rigid skeletons and electron‐rich conjugated systems are beneficial to form permanent porous materials with intrinsic photoelectric properties. In recent years, the research ...related to porous polycarbazoles becomes a hot topic in the field of porous organic polymers. The preparation methods for porous polycarbazoles are diverse, commonly represented by the oxidation coupling reaction and the Friedel–Crafts reaction. Other methods such as nitrile‐based trimerization, electrochemical polymerization, and classic C–C coupling reactions are also reported. Porous polycarbazoles generally possess large specific surface area, permanent pore structure, and high thermal and chemical stability, which show potential applications in gas storage and separation, catalysis, sensors, and electronics. In this review, the recent research progress on the synthetic methods, functions, and applications of porous polycarbazoles is summarized.
Porous polycarbazoles with large surface area, permanent pore structure, and intrinsic photoelectric properties show potential applications in gas storage and separation, catalysis, sensors, and electronics. Recent research progress on the synthetic methods, functions, and applications of porous polycarbazoles is reviewed.
Here, a Sn–C composite material prepared from bulk precursors (tin metal, graphite, and melamine) using ball milling and annealing is reported. The composite (58 wt% Sn and 42 wt% N‐doped carbon) ...shows a capacity up to 445 mAh gSn+C−1 and an excellent cycle life (1000 cycles). For the graphite, the ball milling leads to graphene nanoplatelets (GnP) for which the storage mechanism changes from solvent co‐intercalation to conventional intercalation. The final composite (Sn at nitrogen‐doped graphite nanoplatelets (SnNGnP)) is obtained by combining the GnPs with Sn and melamine as the nitrogen source. Rate‐dependent measurements and in situ X‐ray diffraction are used to study the asymmetric storage behavior of Sn, which shows a more sloping potential profile during sodiation and more defined steps during desodiation. The disappearance of two redox plateaus during desodiation is linked to the preceding sodiation current density (memory effect). The asymmetric behavior is also found by in situ electrochemical dilatometry. This method also shows that the effective electrode expansion during sodiation is much smaller (about +14%) compared to what is expected from Sn (+420%), which gives a reasonable explanation for the excellent cycle life for the SnNGnP (and likely other nanocomposites in general). Next to the advantages, challenges, which result from the nanocomposite approach, are also discussed.
Tin supported by nitrogen‐doped graphene nanoplatelets is found to be an efficient anode for sodium‐ion batteries. Rate‐dependent measurements and in situ diffraction reveal the asymmetric storage behavior of tin within a cycle as well as a memory effect. The in situ electrochemical dilatometry study shows the active role of the support in mitigating the large volume changes of tin during (de)sodiation.
We report a highly efficient iodine adsorbent achieved by rational design of a porous azo‐bridged porphyrin–phthalocyanine network (AzoPPN), which was synthesized by a catalyst‐free coupling reaction ...between free‐base 5,10,15,20‐tetrakis(4‐nitrophenyl)‐porphyrin and nickel tetraaminophthlocyanine. AzoPPN has a permanent porous structure and plenty of porphyrin and phthalocyanine units in the skeleton as effective sorption sites. It displays excellent adsorption of iodine vapor up to 290 wt. % and also shows remarkable capability as adsorbent for iodine in solution. This strategy of combining physisorption with chemisorption in one adsorbent will pave the way for the development of new materials for iodine capture.
Behind bars: A high efficient iodine adsorption was achieved by rational designing of a porous azo‐bridged porphyrin–phthalocyanine network (AzoPPN; see figure). The system displays excellent adsorption of iodine vapor up to 290 wt. % and also distinguished itself with remarkable capability as adsorbent for iodine in solution.
Defects are deliberately introduced into covalent organic frameworks (COFs) via a three‐component condensation strategy. The defective COFs (dCOF‐NH2‐Xs, X = 20, 40, and 60) possess favorable ...crystallinity and porosity, as well as have active amine functional groups as anchoring sites for further postfunctionalization. By introducing imidazolium functional groups onto the pore walls of COFs via the Schiff‐base reaction, dCOF‐ImBr‐Xs‐ and dCOF‐ImTFSI‐Xs‐based materials are employed as all‐solid‐state electrolytes for lithium‐ion conduction with a wide range of working temperatures (from 303 to 423 K), and the ion conductivity of dCOF‐ImTFSI‐60‐based electrolyte reaches 7.05 × 10−3 S cm−1 at 423 K. As far as it is known, it is the highest value for all polymeric crystalline porous material based all‐solid‐state electrolytes. Furthermore, Li/dCOF‐ImTFSI‐60@Li/LiFePO4 all‐solid Li‐ion battery displays satisfactory battery performance under 353 K. This work not only provides a new methodology to construct COFs with precisely controlled defects for postfunctionalization, but also makes them promising candidate materials as all‐solid‐state electrolytes for lithium‐ion batteries operate at high temperatures.
Defective COFs (dCOFs) with active amine functional groups as anchoring sites for postfunctionalization are constructed. After the postfunctionalization process, dCOF‐ImBr‐Xs‐ and dCOF‐ImTFSI‐Xs‐based materials are employed as all‐solid‐state electrolytes for lithium‐ion conduction. As a result, the dCOF‐ImTFSI‐60@Li‐based electrolyte exhibits outstanding lithium‐ion conductivity values, and the Li/dCOF‐ImTFSI‐60@Li/LiFePO4 all‐solid Li‐ion battery displays satisfactory battery performance under 353 K.
This review outlines the the current preparation methods and application of powders, nanosheets, and films of porphyrin- and phthalocyanine-based POPs. The main challenges and prospects for the ...materials are further discussed.
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•Structural design of porphyrin and phthalocyanine monomers.•Preparation methods of porphyrin- and phthalocyanine-based porous organic polymers.•Applications of porphyrin- and phthalocyanine-based porous organic polymers.•Effects of structural designs and material forms for applications.
Porphyrins and phthalocyanines are structurally related macrocyclic compounds with a highly conjugated π-electron system, which exhibit strong absorptions in the visible-light region and extraordinary thermal/chemical stability. Meanwhile, their photophysical properties and electronegativity can be adjusted by changing the metal centers or peripheral substituents. Porous organic polymers (POPs), as a class of emerging porous materials, have been researched extensively and applied in various fields. Porphyrins and phthalocyanines are significant buliding blocks widely used in the construction of POPs on account of their special properties. The incorporation of porphyrin or phthalocyanine in POPs makes the polymers versatile and the application of porphyrin- and phthalocyanine-based porous materials includes catalysis, adsorption, separation, degradation, therapy, and so on. Preparation strategies, structure designs, and monomer functionalizations essentially influence the properties in a certain application. In this review, we first summarize the current preparation methods of powders, nanosheets, and films of porphyrin- and phthalocyanine-based POPs. Then, we introduce the main applications of porphyrin- and phthalocyanine-based materials, focusing on the impact of material construction methods and structural design on performances. Finally, the main challenges and prospects for the materials are further discussed based on our knowledge.
Covalent organic frameworks (COFs) have attracted considerable attention as adsorbents for capturing and separating gold from electronic wastes. To enhance the binding capture efficiency, ...constructing hydrogen‐bond nanotraps along the pore walls was one of the most widely adopted approaches. However, the development of absorbing skeletons was ignored due to the weak binding ability of the gold salts (Au). Herein, we demonstrated skeleton engineering to construct highly efficiently absorbs for Au capture. The strong electronic donating feature of diarylamine units enhanced the electronic density of binding sites (imine‐linkage) and thus resulted in high capacities over 1750 mg g−1 for all three COFs. Moreover, the absorbing performance was further improved via the ionization of diarylamine units. The ionic COF achieved 90 % of the maximal adsorption capacity, 1.63 times of that from the charge‐neutral COF within ten minutes, and showed remarkable uptakes of 1834 mg g−1, exceptional selectivity (97.45 %) and cycling stability. The theoretical calculation revealed the binding sites altering from imine bonds to ionic amine sites after ionization of the frameworks, which enabled to bind the AuCl4− via coulomb force and contributed to enhanced absorbing kinetics. This work inspires us to design molecular/ionic capture based on COFs.
Skeleton engineering was used to form covalent organic frameworks (COFs) with diarylamine derivatives and ionized skeletons, thus overcoming the weak binding ability of Au ions, giving gold adsorbents with high selectivity and uptakes. Experiments and theoretical calculations show that the transition of binding sites from C=N bonds to ionic amine sites, thereby avoiding the protonation process, contributed to enhanced absorbing kinetics.
Photoredox catalysis has aroused great interest from chemists, as it offers a powerful tool for organic synthesis. Cationic polycarbazole networks (CPOP-28 and CPOP-29) were prepared via simple ...oxidative coupling reaction and applied as heterogeneous photocatalysts for a wide range of oxidative organic transformations, including oxidation of sulfides, hydroxylation of arylboronic acids, and cross-dehydrogenative coupling reactions, in the presence of visible light and air. Remarkably, photocatalytic activities are enhanced by ingenious introduction of trifluoromethyl groups to the polymeric network CPOP-29. The effects of the trifluoromethyl group on photocatalytic activities were elucidated in terms of photophysical and electrochemical properties. The appealing photocatalytic performance of the trifluoromethylated polymer is ascribed to superior light-absorption ability, longer fluorescence lifetime, and stronger oxidative capability. In addition, the photocatalysts showed good recyclability and could be reused after a simple separation workup.
A facile approach to disperse graphene in aqueous solution is described. Triblock copolymers (PEO-b-PPO-b-PEO) were employed as the solubilizing agent for chemically exfoliated graphite oxide, and ...graphene formed through in situ reduction by hydrazine. The formation of the stable aqueous copolymer-coated graphene solution is due to the noncovalent interaction between the hydrophobic PPO segments of the triblock copolymer and the hydrophobic graphene surface, whereas the hydrophilic PEO chains extend into water. It was characterized by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. Utilizing the dual roles of Pluronic copolymer in dispersing graphene in aqueous solution and forming supramolecular hydrogel with α-cyclodextrin through the penetration of PEO chains into the cyclodextrin cavities, we further developed a facile and effective method to hybridize the well-dispersed graphene into a supramolecular hydrogel, which was investigated by a variety of techniques, such as X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and rheometer. The supramolecular hybrid hydrogel possessed a cross-linked network and showed shear-thinning properties. The viscosity and strength of the supramolecular hybrid hydrogels decreased significantly as compared to those of the native hydrogel resulting from the lamellar structure of the hybrid hydrogel because of the presence of the graphene sheets. Furthermore, the supramolecular hybrid hydrogel transformed into a sol upon increase in temperature. All these features made our supramolecular hybrid hydrogel a nice candidate in a drug delivery and controlled release system.
We report a facile method for the fabrication of three-dimensional (3D) porous materials via the interaction between graphene oxide (GO) sheets and polyethylenimine (PEI) with high amine density at ...room temperature under atmospheric pressure without stirring. The structural and physical properties of GO–PEI porous materials (GEPMs) are investigated by scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and nitrogen adsorption–desorption measurement and their chemical properties are analyzed by X-ray photoelectron spectroscopy, infrared spectroscopy, and Raman spectroscopy. GEPMs possess low density and hierarchical morphology with large specific surface area, and big pore volume. Furthermore, the as-prepared 3D porous materials show an excellent adsorption capacity for acidic dyes on the basis of the pore-rich and amine-rich graphene structure. GEPMs exhibit an extremely high adsorption capacity for amaranth (800 mg g–1), which are superior to other carbon materials. In addition, GEPMs also exhibit good adsorption capacity for carbon dioxide (11.2 wt % at 1.0 bar and 273 K).
