Porphyrin Covalent Organic Framework Research Articles

One-Pot Green Synthesis of a PEO/TCPP/LiClO4 Solid Polymer Electrolyte with Improvement of Ion Transport

All-solid-state Li-ion batteries (ASSBs) composed of safe and reliable solid electrolyte materials have become increasingly important in energy storage systems. Poly(ethylene oxide) (PEO)-based electrolytes have been rapidly developed for ASSBs over recent years due to their nonflammability, shape flexibility, good interface contact with electrodes, and better electrochemical stability. Nevertheless, their low ionic conductivity remains a serious issue to be addressed urgently. Herein, we report a solid composite polymer electrolyte film with homogeneous network structures, which is composed of a LiClO4-added PEO-based polymer matrix plasticized with an additive meso-tetra (carboxyphenyl) porphyrin (TCPP), a kind of porphyrin covalent organic framework (COF) material, and obtained by a green and easy-to-scale solution-casting technique to improve the ionic conductivity and simplify the synthesis process. To the best of our knowledge, this is the first report on introducing TCPP into the PEO electrolyte. It demonstrates that the blending of PEO with TCPP can effectively suppress the PEO crystallinity and enhance the ion conductivity of the solid polymer electrolytes. As the content of TCPP reaches 8 wt %, it exhibits maximum ionic conductivities of 2.34 × 10–5 and 2.21 × 10–4 S cm–1 at 25 and 65 °C, respectively, which is about five times higher than that of the polymer reference electrolyte. It additionally brings an improved tLi+ value of 0.23 at room temperature with an electrochemical stability window of up to 5 V vs Li+/Li. In addition, when compared to the pure PEO film, a significant improvement in thermal stability is observed. This work may provide a new concept for building a new type of homogeneous COF-PEO-based composite polymer electrolyte film (CPE) that can be utilized as a desirable material in solid electrolytes for lithium-ion battery applications.

Ether-linked porphyrin covalent organic framework with broadband optical switch

SummaryIt is still a challenge to design and synthesize novel switchable optical materials with ultrafast nonlinear optical (NLO) response in a broad spectral range. These materials have exhibited great application potential in many high-technology fields such as biological imaging, chemical sensors, optical data storage, laser protection, and controllable intelligent and optoelectronic devices. By using porphyrins with highly delocalized 18 π-electron conjugated system as functional building blocks, the first ether-linked porphyrin covalent organic framework materials (COF-Pors) with highly ordered lattice structure have been successfully synthesized. In contrast to the starting porphyrins that only exhibit reverse saturable absorption (RSA) response at 532 nm, the as-prepared COF-Pors shows large NLO effect in a broad range from visible to near infrared. Upon laser illumination, COF-Pors exhibits typical saturable absorption (SA) effect at lower incident laser energy, and RSA response at higher pulse energy.

Synergistic Antibacterial and Anti-Inflammatory Effects of a Drug-Loaded Self-Standing Porphyrin-COF Membrane for Efficient Skin Wound Healing.

Chronic wound infections resulting from severe bacterial invasion have become a major medical threat worldwide. Herein, we report a large-area, homogeneous, and self-standing porphyrin-covalent organic framework (COF)-based membrane with encapsulated ibuprofen (IBU) via an in situ interfacial polymerization and impregnation approach. The obtained IBU@DhaTph-membrane exhibits highly effective antibacterial and anti-inflammatory effects via synergistic light-induced singlet oxygen (1 O2 ) generation and controllable IBU release, which is well supported by in vitro experiments. In addition, the IBU@DhaTph-membrane-based biocompatible "band-aid" type dressing is fabricated, and its excellent anti-infection and tissue remodeling activities are fully evidenced by in vivo chronic wound-healing experiments. This study may inspire and promote the fabrication of many more new types of COF-based multifunctional biomaterials for various skin injuries in clinical medicine.

Two-dimensional porphyrin covalent organic frameworks with tunable catalytic active sites for the oxygen reduction reaction.

Four novel two-dimensional porphyrin COFs (M-TP-COF, M = H2, Co, Ni and Mn) with donor-acceptor dyads were fabricated and served as electrocatalysts for the oxygen reduction reaction (ORR). The ORR catalytic activity of M-TP-COF was tuned by changing the M atom in the center of the porphyrin backbone. The experimental structure-function relationship was in accordance with the results of density functional theory calculations based on the O2-O2*-OOH*-O*-OH*-OH- route.

Fe3O4/Porphyrin Covalent Organic Framework Core–Shell Nanospheres as Interfacial Catalysts for Enzymatic Esterification

A nanoscale core-shell-structured magnetic microsphere (abbreviated as Fe3O4@DhaTph-lipase), which consists of an Fe3O4 core, a porphyrin covalent organic framework DhaTph shell with loaded lipase, is reported. The obtained Fe3O4@DhaTph-lipase microsphere can be a powerful emulsifier to stabilize the water-in-n-hexane Pickering emulsion for at least one month without any demulsification under ambient conditions. Furthermore, Fe3O4@DhaTph-lipase with lipase enzyme and a large specific surface area is a droplet microreactor and displays excellent interfacial catalytic activity to promote enzymatic esterification reaction via visible light-induced photothermal conversion. On the other hand, the magnetically triggered Pickering emulsion interfacial catalyst can be recycled at least 10 times with robust performance. The potential utility of this strategy is highlighted by the fabrication of many more multifunctional covalent organic framework-based Pickering emulsion catalytic systems to promote various organic transformations in a green, smart, and facile way.

2D sp2Carbon‐Conjugated Porphyrin Covalent Organic Framework for Cooperative Photocatalysis with TEMPO

Abstract2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2carbon‐conjugated porphyrin‐based covalent organic framework (Por‐sp2c‐COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light‐emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π‐conjugation of porphyrin linker leads to extensive absorption of red light; the sp2−C=C− double bonds linkage ensures the stability of Por‐sp2c‐COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por‐sp2c‐COF is pivotal for cooperative photocatalysis with (2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.

2D sp2 Carbon-Conjugated Porphyrin Covalent Organic Framework for Cooperative Photocatalysis with TEMPO.

2D covalent organic frameworks (COFs) are receiving ongoing attention in semiconductor photocatalysis. Herein, we present a photocatalytic selective chemical transformation by combining sp2 carbon-conjugated porphyrin-based covalent organic framework (Por-sp2 c-COF) photocatalysis with TEMPO catalysis illuminated by 623 nm red light-emitting diodes (LEDs). Highly selective conversion of amines into imines was swiftly afforded in minutes. Specifically, the π-conjugation of porphyrin linker leads to extensive absorption of red light; the sp2 -C=C- double bonds linkage ensures the stability of Por-sp2 c-COF under high concentrations of amine. Most importantly, we found that crystalline framework of Por-sp2 c-COF is pivotal for cooperative photocatalysis with (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO). This work foreshadows that the outstanding hallmarks of COFs, particularly crystallinity, could be exploited to address energy and environmental challenges by cooperative photocatalysis.

In Situ Bottom-up Synthesis of Porphyrin-Based Covalent Organic Frameworks.

Synthesis and processing of two- or three-dimensional covalent organic frameworks (COFs) have been limited by solvent intractability and sluggish condensation kinetics. Here, we report on the electrochemical deposition of poly(5,10,15,20-tetrakis(4-aminophenyl)porphyrin)-covalent organic frameworks (POR-COFs) via formation of phenazine linkages. By adjusting the synthetic parameters, we demonstrate the rapid and bottom-up synthesis of COF dendrites. Both experiment and density functional theory underline the prominent role of pyridine, not only as a polymerization promoter but as a stabilizing sublattice, cocrystallizing with the framework. The crucial role of pyridine in dictating the structural properties of such a cocrystal (Py-POR-COF) is discussed. Also, a structure-to-function relationship for this class of materials, governing their electrocatalytic activity for the oxygen reduction reaction in alkaline media, is reported.

Facile Synthesis of Porphyrin Based Covalent Organic Frameworks via an A2B2 Monomer for Highly Efficient Heterogeneous Catalysis

A new porphyrin covalent organic framework (A2B2-Por-COF) was readily constructed via self-polycondensation of an A2B2 porphyrin monomer. In contrast to the previously reported porphyrin COFs prepa...

Porphyrin Covalent Organic Framework (POF)‐Based Interface Engineering for Solar Steam Generation

AbstractThrough replacement of traditional energy sources with sunlight as the heat source, solar steam generation has emerged as a promising technology for water purification and residuals management. Despite significant efforts to develop efficient photothermal materials for solar steam devices, challenges associated with scalable fabrication of high‐performance materials remain. Moreover, most existing methods cannot be easily engineered to produce steam‐generating devices with both arbitrary control over shape and high photothermal efficiency. Herein, a flexible porphyrin organic framework (POF)‐based interface engineering method is introduced to produce high‐performance solar steam generators. POFs, a recently discovered class of materials, are demonstrated to grow readily on a diverse range of porous substrates, including membranes, fabrics, sponges, and wood. Wood@POF exhibits particularly strong performance, achieving ≈80% light‐to‐steam conversion efficiency. This study demonstrates a universal, simple, and scalable interface engineering strategy for the fabrication of solar steam generators based on POF materials.

Two-dimensional graphdiyne analogue Co-coordinated porphyrin covalent organic framework nanosheets as a stable electrocatalyst for the oxygen evolution reaction

Employing metalloporphyrin as monomer is an effective strategy to overcome the drawback of graphdiyne in electrocatalytic process. The Co–N4 active centers, expanded pores, and conjugated structure altogether endow the Co-PDY with excellent OER catalytic performance.

Fluorescence-enhanced covalent organic framework nanosystem for tumor imaging and photothermal therapy.

Fluorescent dyes, as a key factor in fluorescence imaging, usually exhibit a low signal-to-noise ratio (SNR) due to the limited loading capacities of delivery systems (usually less than 10.0 wt%) and their uncontrolled release. Herein, we developed a type of pH-responsive nanoplatform (MnO2/ZnCOF@Au&BSA) based on a zinc porphyrin covalent organic framework (COF), in which the zinc porphyrin (ZnPor) loading rate is 22.5 wt%. At pH = 7.4, the interlinked ZnPor in the assembly state did not show a fluorescence signal ("off" state). Together with the pH-triggered disintegration of ZnCOF in tumor cells (pH = 5.5), the scattered ZnPor displayed an obvious fluorescence signal recovery ("on" state). Simultaneously, the shed BSA-coated gold nanoparticles ingeniously caused the fluorescence signal to be further amplified through the metal-enhanced fluorescence effect, which was about 3.0-fold higher in vivo than in the free ZnPor group. Combined with the excellent photothermal therapy effect by the nanoplatform itself with the tumor inhibition rate of 79.5%, this nanosystem effectively solves the problem of low loading capacities and imaging SNR by traditional delivery systems, and successfully develops the potential of COFs for fluorescence imaging, achieving the purpose of integration of diagnosis and treatment.

Hydrogen adsorption in pyridine bridged porphyrin-covalent organic framework

Covalent organic frameworks (COFs), a class of carbon-based polymeric materials have the potential to be used as hydrogen adsorbent. Three dimensional (3D) COFs, due to their low density and high surface area, although have higher hydrogen adsorption, they have less stability than two dimensional (2D) COFs. Here we studied porphyrin group containing 2D COF, namely H2,P-COF for hydrogen storage using density functional theory (DFT) and grand canonical Monte Carlo (GCMC) simulations and the results were compared with the most common 2D COFs, COF-1 and COF-5. Cylindrical shaped 2D COFs where isolated unit blocks are stacked in multiple layers due to van der Waals interactions between individual layers, increase the effective surface area for hydrogen storage. A further modification has been done by bridging the inter-layer gap by pyridine molecules. Insertion of pyridine increases the separation distance of layers of 2D COFs as well as the free volume. Feasibility of the structure formation and stability of all the structures were checked using DFT study. To ensure the structural stability of bridged COFs after hydrogen loading, alternating layers of COF were bridged. Single, bi, tri and tetra -pyridine molecules were chemically bonded with the existing carbon ring present in between two C2O2B rings to form pyridine bridged H2,P-COFs. Our GCMC results show a significant increase in storage capacity which is mainly due to an increase in the free volume of the material. The highest capacity of ∼ 5.1 wt% and 20 g H2/L at 298 K and 100 bar, above the gravimetric DOE goal, has been found at room temperature for tetra-pyridine doped porphyrin COF structure.

A porphyrin covalent organic framework cathode for flexible Zn–air batteries

A porphyrin covalent organic framework cathode is fabricated under multiscale materials regulation for flexible Zn–air batteries.

A reduced graphene oxide/covalent cobalt porphyrin framework for efficient oxygen reduction reaction.

A reduced graphene oxide/covalent cobalt porphyrin framework has been synthesized by using pyridine-functionalized reduced graphene oxide (G-dye) as the building block. Due to the unique 3-dimensional architecture and good electronic properties of graphene, as well as the electron accepting ability of the nitrogen atoms in the G-dye, the as-synthesized CoCOF-Py-0.05rGO catalyst exhibits excellent oxygen reduction reaction (ORR) activity with superior long-term stability and methanol tolerance.

Novel imine-linked porphyrin covalent organic frameworks with good adsorption removing properties of RhB

A porphyrin COF was constructed and post-treated with FeCl3 which led to the CuP-DMNDA-COF/Fe material displaying superior adsorption performance for RhB.

Thermodynamic self-assembly of two-dimensional pi-conjugated metal-porphyrin covalent organic frameworks by "on-site" equilibrium polymerization.

Two-dimensional pi-conjugated metal-porphyrin covalent organic frameworks were produced in aqueous solution on an iodine-modified Au(111) surface by "on-site" azomethine coupling of Fe(III)-5,10,15,20-tetrakis(4-aminophenyl)porphyrin (FeTAPP) with terephthal dicarboxaldehyde and investigated in detail using in-situ scanning tunneling microscopy. Mixed covalent organic porphyrin frameworks consisting of FeTAPP and metal-free TAPP (H2TAPP) were prepared through simultaneous adsorption in a mixed solution as well as partial replacement of FeTAPP by H2TAPP in an as-prepared metal-porphyrin framework. In the mixed framework, the relative distribution of FeTAPP to H2TAPP was not random and revealed a preference for homo-connection rather than heteroconnection. The construction of substrate-supported, pi-conjugated covalent frameworks from multiple building blocks, including metal centers, will be of significant utility in the design of functional molecular nanoarchitectures.

A Squaraine‐Linked Mesoporous Covalent Organic Framework

π in the sky: A squaraine-linked, conjugated two-dimensional porphyrin covalent organic framework (COF; see scheme; C: gray, H: white, N: blue, Cu: red) was synthesized. Owing to the π-conjugated linkage together with the eclipsed stacking of the units, this COF exhibits enhanced chemical and thermal stabilities. It absorbs a broad range of light, from the ultraviolet to the visible, and near-infrared regions, and shows potential as a photocatalyst.

High‐Rate Charge‐Carrier Transport in Porphyrin Covalent Organic Frameworks: Switching from Hole to Electron to Ambipolar Conduction

High‐Rate Charge‐Carrier Transport in Porphyrin Covalent Organic Frameworks: Switching from Hole to Electron to Ambipolar Conduction

High‐Rate Charge‐Carrier Transport in Porphyrin Covalent Organic Frameworks: Switching from Hole to Electron to Ambipolar Conduction

Well conducted: a two-dimensional porphyrin covalent organic framework is described. Owing to the eclipsed stacking alignment, the framework is conductive and allows high-rate carrier transport through the porphyrin columns. The central metal in the porphyrin rings changes the conducting nature of the material from hole to electron, and to ambipolar conduction. It also drives the high on-off ratio photoconductivity of the framework.