An Elastic Monolithic Catalyst: A Microporous Metalloporphyrin‐Containing Framework‐Wrapped Melamine Foam for Process‐Intensified Acyl Transfer

Composite Graphene for the Dimension- and Pore-Size-Mediated Stem Cell Differentiation to Bone Regenerative Medicine

As one of the most promising means to repair diseased tissues, stem cell therapy with immense potential to differentiate into mature specialized cells has been rapidly developed. However, the clinical application of stem-cell-dominated regenerative medicine was heavily hindered by the loss of pluripotency during the long-term in vitro expansion. Here, a composite three-dimensional (3D) graphene-based biomaterial, denoted as GO-Por-CMP@CaP, with hierarchical pore structure (micro- to macropore), was developed to guide the directional differentiation of human umbilical cord MSCs (hucMSCs) into osteoblasts. GO-Por-CMP@CaP could act as a high-efficiency living composite material without a "dead space", effectively regulating the cellular response. The 3D topological structure generated via the two-step modification on two-dimensional graphene could effectively mimic the natural 3D microenvironment of cells, enhancing the stem cell attachment, which is not only conducive for the proliferation of stem cells but also beneficial for the osteogenic differentiation. Meanwhile, the wide existence of interconnected macropores was favorable for bone ingrowth, capillary formation, as well as the nutrients transportation. Furthermore, the concurrent existence of micro- and mesopores significantly promoted the extracellular matrix (ECM) adsorption, which ensured cellular attachment, leading to multiscale osteointegration. Both in vitro and in vivo assay demonstrated the above three factors collaborated mutually with nanosized calcium phosphate (CaP, with chemical similarities to the inorganic components of bone), which provided abundant adhesive sites to adequately induce osteogenic differentiation in the absence of any soluble growth factors. Proteomic analysis experiments confirmed that GO-Por-CMP@CaP promoted the differentiation of hucMSCs cells into osteoblasts by affecting the PI3K-Akt signaling pathway through the up-regulation of SPP1 protein. Our study offers a pure material-based stem cell differentiation regulating behavior via engineering the dimension and porosity of material, which provides insights into the design and development of substitutes to bone repair materials.

Three Birds with One Sulfur: Construction of Sulfur-Bridged Porous Organic Polymers for Efficient Gold Adsorption

Sulfur is a massive byproduct of the petrochemicals industry and hardly employed as a building block for porous organic polymers (POPs). Here, a new family of sulfur-bridged POPs has been prepared via a C-H insertion reaction between sulfur and polycyclic aromatic hydrocarbons. Sulfur works as a solvent, external cross-linker, and porogen simultaneously during the polymerization process. The products demonstrate high porosity and maximum surface area of 1050 m2 g-1 with abundant accessible active sites, contributing to the nanometerization of sulfur and significantly enhancing the inherent affinity between heteroatoms toward soft metal ions. Therefore, they exhibit a high absorption capacity for Au(III) of 3287 mg g-1 and excellent absorption selectivity and removal efficiency via a performance evaluation even in real electronic wastewater. This synthetic strategy to prepare high added-value functional POPs with sulfur not only sheds light on designing high-performance gold adsorption materials and emerging POPs, but also promotes a sustainable development protocol.

A heteropore covalent organic framework for highly selective enrichment of aryl-organophosphate esters in environmental water coupled with UHPLC-MS/MS determination

The identification of an increasing number of aryl organophosphate esters (aryl-OPEs) in environmental samples has led to growing attention recently. Due to the potential adverse effects on human health and environment, development of new analytical methods for sensitive and selective determination of aryl-OPEs in complex matrices is urgently needed. Here, a novel analytical method for the identification and determination of trace amounts of aryl-OPEs in water samples is developed by using melamine sponge@heteropore covalent organic framework (MS@HCOF) based on vortex-assisted extraction (VAE) prior to UHPLC-MS/MS analysis. The MS@HCOF was rationally designed and synthesized through an in-situ growth strategy and exhibited superior selectivity toward aryl-OPEs compared with that of MS@single-pore COF (MS@SCOF) due to steric effect. A systematic optimization was conducted on important parameters of VAE, resulting in the successful extraction of nine aryl-OPEs in just 6 min. Under optimized conditions, the limits of detection (S/N = 3) and quantification (S/N = 10) were within the ranges of 0.001-0.027 and 0.005-0.091 ng/L for nine aryl-OPEs, respectively. The validated method was proven applicable to real water samples, i.e., the recoveries were 65.3-119.5 % for seawater, 59.4-112.9 % for effluent, and 76.0-117.4 % for tap water. Furthermore, the adsorption mechanisms were explored through density functional theory (DFT) calculations. DFT results revealed that a notable selective enrichment capacity of MS@HCOF towards aryl-OPEs stems from π-π conjugation and hydrogen bonding. The established method benefits from the advantages of high selectivity and sensitivity for the ultra-trace determination of aryl-OPEs.

Composite porphyrin-based conjugated microporous polymer/graphene oxide capable of photo-triggered combinational antibacterial therapy and wound healing

Developing antibiotic-free treatment strategies to cope with the crisis on drug-resistant bacteria, are urgently needed. Antibiotics-independent physical approaches, especially the non-invasive phototherapies, worked through the assistance of photosensitizer (PS), have geared intensive attention and interests. Here, composite porphyrin-based conjugated microporous polymer/graphene oxide, denoted as GO-TAPP, combining the advantages of each component perfectly, was developed as broad-spectrum antibacterial agent. GO-TAPP, prepared via the self-oxidation coupling of tetraethynyl porphyrin on the surface of graphene oxide, could exert synergistic photothermal (PTT, ascribed to the graphene) and photodynamic (PDT, derived from the Porphyrin polymer) antimicrobial effectiveness. Both the in vivo and in vitro experiments have confirmed GO-TAPP are extremely potent against the Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) pathogens, which presents a remarkably enhanced sterilizing effect in comparison with its counterparts (the bare GO, and TAPP). Meanwhile, the synergistic effect of GO-TAPP could significantly accelerate the healing of open wound infected by bacterial. Altogether, this work proposed a new approach for the rational preparation of highly biocompatible graphene-based composite materials as antibiotic-free agents with synergistic antibacterial effect to combat bacterial infections.

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.

Pendant Length-Dependent Electrochemical Performances for Conjugated Organic Polymers as Solid-State Polymer Electrolytes in Lithium Metal Batteries

The development of solid-state polymer electrolytes (SPEs) has been plagued by poor ionic conductivity, low ionic transference number, and limited electrochemical potential window. The exploitation of ionized SPEs is a feasible avenue to solve this problem. Herein, conjugated organic polymers (COPs) with excellent designability and rich pore structures have been selected as platforms for exploration. Three cationic COPs with different chain lengths of quaternary ammonium salts (CbzT@C_x, x = 4, 6, 9) are designed and applied to SPEs for the first time. Meanwhile, the effects of chain lengths on their electrochemical performances are compared. Especially, CbzT@C₉ shows the most attractive electrochemical performance due to its high specific surface area of 212.3 m² g^-1. The larger specific surface area allows more exposure of the long-chain quaternary ammonium cation groups, which is more favorable for the dissociation of lithium salts. Moreover, the flexible long-chain structure increases the compatibility with poly(ethylene oxide) (PEO) and reduces the crystallinity of PEO to some extent. The richer pore structure can accommodate more PEO, further disrupting the crystallinity of PEO and creating more channels for the ether-oxygen chain to transport lithium ions. At 60 °C, the SPE (CbzTM@C₉) presents an excellent ionic conductivity (σ) of 8.00 × 10^-4 S cm^-1. CbzTM@C₉ has a lithium-ion transference number (t_Li+) of 0.48. Thus, the assembled Li/CbzTM@C₉/LiFePO₄ battery provides a good discharge capacity of 158.8 mAh g^-1 at 0.1C. After 70 cycles, the capacity retention rate is 93.8% with a Coulombic efficiency of 98%. The excellent flexibility brings stable power supply capability under various bending angles to the assembled Li/CbzTM@C₉/LiFePO₄ soft-packed battery. The project uses conjugated organic polymers in SPEs and creates an avenue to develop flexible energy storage equipment.

Processable Conjugated Microporous Polymer Gels and Monoliths: Fundamentals and Versatile Applications

Conjugated microporous polymers (CMPs) as a new type of conjugated polymers have attracted extensive attention in academia and industry because of the combination of microporous structure and π-electron conjugated structure. The construction and application of gels and monoliths based on CMPs constitute a fertile area of research, promising to provide solutions to complex environmental and energy issues. This review summarizes and objectively analyzes the latest advances in the construction and application of processable CMP gels and monoliths, linking the basic and enhanced properties to widespread applications. In this review, we open with a summary of the construction methods used to build CMP gels and monoliths and assess the feasibility of different preparation techniques and the advantages of the products. The CMP gels and monoliths with enhanced properties involving various special applications are then deliberated by highlighting relevant scientific literature and discussions. Finally, we present the issues and future of openness in the field, as well as come up with the major challenges hindering further development, to guide researchers in this field.

Enhancing Built-in Electric Field via Molecular Dipole Control in Conjugated Microporous Polymers for Boosting Charge Separation

The built-in electric field (BEF) has been considered as the key kinetic factor for facilitating efficient photoinduced carrier separation and migration of polymeric photocatalysts. Enhancing the BEF of the polymers could enable a directional migration of the photogenerated carriers to accelerate photogenerated charge separation and thus boost photocatalytic performances. However, achieving this approach remains a formidable challenge, which has never been realized in conjugated microporous polymers (CMPs). Herein, we developed a molecular dipole control strategy to modulate the BEF in CMPs by varying the nature of the core. As a result, a series of CMPs with a tunable BEF were designed and prepared via FeCl₃-mediated coupling of bicarbazole with different acceptor cores. The optimized CbzCMP-9 featured the strongest BEF induced by its high molecular dipole, which grants it with a powerful driving force to accelerate exciton dissociation into electron-hole pairs and facilitates charge transfer along the backbone of CMPs to the surface, resulting in a remarkable photocatalytic performance toward thiocyano chromones and C-3 thiocyanation of indoles (up to 95 and 98% yields, respectively) and prominently surpassing many other reported photocatalysts. In brief, the proposed strategy highlights that enhancing the BEF by modulating molecular dipole can lead to a dramatic improvement in photocatalytic performance, which is expected to be employed for constructing other photocatalytic systems with high performance.

Non-Precious Metal-Doped Carbon Materials Derived From Porphyrin-Based Porous Organic Polymers for Oxygen Reduction Electrocatalysis

The cathodic oxygen reduction reaction (ORR) is important in the development of renewable energy devices, to produce novel and non-precious metal catalysts with high electrocatalytic activity to reduce the consumption of non-renewable platinum (Pt) catalyst. In this work, we developed N-doped and Fe/N dual-doped porous carbons as catalysts for ORR simply by high-temperature pyrolysis of porphyrin-based conjugated microporous polymers (CMPs). By combination of heteroatom doping, highly porous structure and tubular morphology, the as-prepared carbon samples exhibited high electrocatalytic activity with 4-electron transfer mechanism, nearly close to the commercial Pt/C catalyst. In particular, among these samples, the Fe/N-CMP-1000 displayed a higher onset potential (0.95 eV), positive half-wave potential (0.85 eV) and limiting current density value (5.1 mA cm^-2 ) as well as good durability and better methanol tolerance contrasting with Pt/C catalyst, suggesting that the as-prepared metal-free catalysts from porphyrin-based CMPs show great potential for ORR.

Multivariate Synthetic Strategy for Improving Crystallinity of Zwitterionic Squaraine-Linked Covalent Organic Frameworks with Enhanced Photothermal Performance

Two-dimensional covalent organic frameworks (2D COFs) offer a designable platform to explore porous polyelectrolyte frameworks with periodic ionic skeletons and uniform pore channels. However, the crystallinity of ionized 2D COF is often far from satisfactory as the electrostatic assembly of structures impedes the ordered layered arrangement. Here, a multivariate synthetic strategy to synthesize a highly crystalline squaraine (SQ)-linked zwitterionic 2D COF is proved. A neutral aldehyde monomer copolymerizes with squaric acid (SA) and amines in a controlled manner, resulting in the ionized COF with linkage heterogeneity in one tetragonal framework. Thus, the zwitterions of SQ are spatially isolated to minimize the electrostatic interaction and maintain the highly ordered layered stacking. With the addition of 85%-90% SA (relative to a total of aldehydes and SA), a fully SQ-linked zwitterionic 2D COF is achieved by the in-situ conversion of imine to SQ linkages. Such a highly crystalline SQ-linked COF promotes absorptivity in a full spectrum and photothermal conversion performances, and in turn, it exhibits enhanced solar-to-vapor generation with an efficiency of as high as 92.19%. These results suggest that synthetically regulating charge distribution is desirable to constitute a family of new crystalline polyelectrolyte frameworks.

Removal of Chromium(VI) by Nanoscale Zero-Valent Iron Supported on Melamine Carbon Foam

The overuse of chromium (Cr) has significantly negatively impacted human life and environmental sustainability. Recently, the employment of nano zero-valent iron (nZVI) for Cr(VI) removal is becoming an emerging approach. In this study, carbonized melamine foam-supported nZVI composites, prepared by a simple impregnation–carbonization–reduction method, were assessed for efficient Cr(VI) removal. The prepared composites were characterized by XPS, SEM, TEM, BET and XRD. Batch experiments at different conditions revealed that the amount of iron added, the temperature of carbonization and the initial Cr(VI) concentration were critical factors. Fe@MF-12.5-800 exhibited the highest removal efficiency of 99% Cr(VI) (10 mg/L) at neutral pH among the carbonized melamine foam-supported nZVI composites. Its iron particles were effectively soldered onto the carbonaceous surfaces within the pore networks. Moreover, Fe@MF-12.5-800 demonstrated remarkable stability (60%, 7 days) in an open environment compared with nZVI particles.

Macroscale Conjugated Microporous Polymers: Controlling Versatile Functionalities Over Several Dimensions

Since discovered in 2007, conjugated microporous polymers (CMPs) have been developed for numerous applications including gas adsorption, sensing, organic and photoredox catalysis, energy storage, etc. While featuring abundant micropores, the structural rigidity derived from CMPs' stable π-conjugated skeleton leads to insolubility and thus poor processability, which severely limits their applicability, e.g., in CMP-based devices. Hence, the development of CMPs whose structure can not only be controlled on the micro- but also on the macroscale have attracted tremendous interest. In conventional synthesis procedures, CMPs are obtained as powders, but in recent years various bottom-up synthesis strategies have been developed, which yield CMPs as thin films on substrates or as hybrid materials, allowing to span length scales from individual conjugated monomers to micro-/macrostructures. This review surveys recent advances on the construction of CMPs into macroscale structures, including membranes, films, aerogels, sponges, and other architectures. The focus is to describe the underlying fabrication techniques and the implications which follow from the macroscale morphologies, involving new chemistry and physics in such materials for applications like molecular separation/filtration/adsorption, energy storage and conversion, photothermal transformation, sensing, or catalysis.

In situ construction of self-supporting Ni–Fe sulfide for high-efficiency oxygen evolution

2D nanosheet arrays comprising the self-supporting (Fe,Ni)3S4 composite not only exhibit excellent OER activity but also superior reaction stability due to the combined effect of mesopore-containing 2D nanosheets and the binary metal species.

Optimization, Characterization and Pharmacokinetic Study of Meso-Tetraphenylporphyrin Metal Complex-Loaded PLGA Nanoparticles

The selection of technological parameters for nanoparticle formulation represents a complicated development phase. Therefore, the statistical analysis based on Box-Behnken methodology is widely used to optimize technological processes, including poly(lactic-co-glycolic acid) nanoparticle formulation. In this study, we applied a two-level three-factor design to optimize the preparation of nanoparticles loaded with cobalt (CoTPP), manganese (MnClTPP), and nickel (NiTPP) metalloporphyrins (MeP). The resulting nanoparticles were examined by dynamic light scattering, X-ray diffraction, Fourier transform infrared spectroscopy, MTT test, and hemolytic activity assay. The optimized model of nanoparticle formulation was validated, and the obtained nanoparticles possessed a spherical shape and physicochemical characteristics enabling them to deliver MeP in cancer cells. In vitro hemolysis assay revealed high safety of the formulated MeP-loaded nanoparticles. The MeP release demonstrated a biphasic profile and release mechanism via Fick diffusion, according to release exponent values. Formulated MeP-loaded nanoparticles revealed significant antitumor activity and ability to generate reactive oxygen species. MnClTPP- and CoTPP-nanoparticles specifically accumulated in tissues, preventing wide tissue distribution caused by long-term circulation of the hydrophobic drug. Our results suggest that MnClTPP- and CoTPP-nanoparticles represent the greatest potential for utilization in in anticancer therapy due to their effectiveness and safety.

Hyperporous magnetic catalyst foam for highly efficient and stable adsorption and reduction of aqueous organic contaminants

The facile and low-cost fabrication of free-standing magnetic catalysts with high catalytic efficiency, rapid reaction rate and excellent recoverability has been pursued for various catalysis applications, e.g., treating aqueous organic 4-nitrophenol pollutants. Here, we design and fabricate a free-standing nickel-coated hyperporous polymer foam (Ni-HPF) with adjustable shapes and sizes, hierarchical multiscale porous structures, abundant catalytical interfaces and excellent super-paramagnetic properties. Due to the synergistical effect of abundant binding sites and highly catalytic reduction, the as-prepared Ni-HPF has demonstrated high conversion efficiency (> 90% at extremely low concentration of 7.5 μM) and rapid reaction rate (2.58 × 10^-3 s^-1) for the reduction of organic 4-nitrophenol. Moreover, the magnetic catalyst also holds excellent recoverability (>80% conversion rate even after 1000 cycles) and good reproducibility (>80% conversion rate after 3 months of storage). As such, this work with novel material design and working principle could provide a wide range of potential applications in water purification, chemical catalysis and energy storage devices.

Multi-Synergistic Removal of Low-Boiling-Point Contaminants with Efficient Carbon Aerogel-Based Solar Purifier

Solar steam generation is considered as an efficient way for addressing water shortage issues via seawater desalination and wastewater purification. In a solar evaporator, an absorber would convert optical energy to heat for evaporating nearby water. In this process, many low-boiling-point contaminants can also be evaporated along with water steam, which compromises the effectiveness of purification. There is, so far, no study on the removal of such low-boiling-point contaminants such as organic pesticides in wastewater. To address this problem, we demonstrate a versatile carbon hybrid aerogel (CHA) as a solar powered water purification platform. With an elaborate absorber design, the maximum solar evaporation rate of 2.1 kg m^-2 h^-1 is achieved under 1 sun illumination. More importantly, CHA can effectively suppress the evaporation of low-boiling-point contaminants including common pesticides and mercury ion via its strong adsorption and retention effect. Synergetic steaming and the adsorption of CHA will inspire more paradigms of solar steam generation technologies for applications relevant to detoxification and water remediation.

One-pot room-temperature synthesis of covalent organic framework-coated superhydrophobic sponges for highly efficient oil-water separation

Frequent oil-spill accidents not only cause serious and long-term damage to marine ecosystems, but also lead to a huge loss of valuable natural resources. To lighten the environmental pollution of oil spills as quickly as possible, an efficient and environment-friendly approach for oil-water separation is highly desirable. Herein, a facile one-pot room-temperature approach was developed for large-scale fabrication of covalent organic framework-coated superhydrophobic sponges (sponges@COFs). The as-prepared sponges@COFs possessed many superior properties, including superhydrophobicity with the water contact angle of approximately 154.3°, large specific surface area (153.059 m²/g), high porosity of the network structures, as well as good mechanical and chemical stability. Taking the aformentioned advantages together, the superhydrophobic sponges showed ultra-high adsorption capacity for oil and various organic solvents. In comparision with its own weight, the adsorption amount of the sponges@COFs for silicone oil was up to 150 times and for toluene was 125 times, respectively. Furthermore, the superhydrophobic sponges also showed fast and highly efficient oil-water separation, outstanding flame retardancy and recyclability. In addition, the sponges@COFs were successfully applied to the high-efficiency removal of oil suspension from industrial waste water, firmly confirming their application prospect in industrial wastewater treatment.

Conjugated microporous polymer foams with excellent thermal insulation performance in a humid environment

This work reported two monolithic conjugated microporous polymer (CMP) foams synthesized through the Sonogashira-Hagihara cross-coupling reaction without mechanical stirring. The as-synthesized (CMP-ED and CMP-PT) foams exhibited superior hydrophobicity and low apparent density of 58 mg cm-3 and 63 mg cm-3. In addition, CMP-ED displayed a low thermal conductivity of 34.04 mW m-1 K-1, which was comparable with commercial SiO2 aerogels (34.09 mW m-1 K-1) at 50% humidity conditions. When the environment humidity was raised from 50% to 70%, the thermal conductivity of CMP-ED and commercial SiO2 aerogels improved by 0.12% and 7%, respectively. Furthermore, XRD, FTIR, BET and TG were conducted to evaluate the bulk structure and stability of CMP-ED and CMP-PT. The results illustrated the thermal conductivity values were greatly affected by the pore structure of foams. And the strong hydrophobicity and the narrow pore structure were responsible for the good thermal insulation performance under humid conditions. Considering the low density, superhydrophobicity, excellent physicochemical stability and impervious thermal conductivity in a high humidity environment, this CMP-ED presented great potential as an insulating material in a humid environment.

A silsesquioxane-porphyrin-based porous organic polymer as a highly efficient and recyclable absorbent for wastewater treatment

Effective capture of pollutants from wastewater is crucial for protecting the environment and human health. An azo-based porous organic polymer (AzoPPOP) containing porphyrin and inorganics cage polyhedral oligomeric silsesquioxane units was synthesized via a catalyst-free coupling reaction. Results showed that AzoPPOP possess a high surface area, a hierarchically porous structure, good thermal stability, abundant adsorption sites, and an electronegative nature. Based on these properties, AzoPPOP had an extremely high adsorption capacity (1357.58 mg g^-1) for RhB, a fast adsorption rate, and good selectivity. Study of the mechanism revealed that in addition to electrostatic interactions, the high specific surface area, existence of -NH₂, and the strong π-π interaction between AzoPPOP and RhB also play important roles for the adsorption of RhB. AzoPPOP also displayed excellent adsorption properties for heavy metal ions (230.45, 192.24 and 162.11 mg g^-1 for Ag⁺, Hg²⁺, and Pb²⁺, respectively). More importantly, simulation of the purification experiment of waste water and the recycling regeneration experiment revealed that AzoPPOP has good high-level recyclability and could remove multi-pollutants in one pass through a simple adsorption column.

Nanoscale integration of porphyrin in GroEL protein cage: Photophysical and photochemical investigation

In this paper, we introduce a new type of functional, supramolecular porphyrin conjugate created using the bacterial GroEL protein cage based on non-specific hydrophobic interaction. The synthesis, structure and property of the porphyrin conjugate were characterized by dynamic light scattering, UV-vis spectroscopy and fluorescence spectroscopy. We observed that the model zinc-tetraphenylporphyrin (Zn-TPP) with high hydrophobicity can be well-dispersed in aqueous solutions with the aid of GroEL open chamber, which is known to be a favorable nanocompartment for aggregation-prone molecules. The maximal encapsulation efficiency of Zn-TPP in GroEL was determined to be ~98%. It is further seen that the constructed double Zn-TPP-GroEL complex exhibited good photocatalytic activity in the model reactions of the production of singlet oxygen and the reduction of methyl viologen under illumination with visible light. Moreover, we found that GroEL can significantly improve the photostability of Zn-TPP molecules as a result of nanoscale assembly within its hydrophobic chamber. Hence enhanced water solubility and photostability of Zn-TPP, which are considered as the first two hurdles for the wide usage of porphyrins, were achieved simultaneously by the development of GroEL cage as a building block. Supramolecular nanostructures formed from porphyrins (or related molecules) and GroEL for photocatalysis would greatly simplify applications of such structures.

Tailored Porous Organic Polymers for Task-Specific Water Purification

The Industrial Revolution has resulted in social and economic improvements, but unfortunately, with the development of manufacturing and mining, water sources have been pervaded with contaminants, putting Earth's freshwater supply in peril. Therefore, the segregation of pollutants-such as radionuclides, heavy metals, and oil spills-from water streams, has become a pertinent problem. Attempts have been made to extract these pollutants through chemical precipitation, sorbents, and membranes. The limitations of the current remediation methods, including the generation of a considerable volume of chemical sludge as well as low uptake capacity and/or selectivity, actuate the need for materials innovation. These insufficiencies have provoked our interest in the exploration of porous organic polymers (POPs) for water treatment. This category of porous material has been at the forefront of materials research due to its modular nature, i.e., its tunable functionality and tailorable porosity. Compared to other materials, the practicality of POPs comes from their purely organic composition, which lends to their stability and ease of synthesis. The potential of using POPs as a design platform for solid extractors is closely associated with the ease with which their pore space can be functionalized with high densities of strong adsorption sites, resulting in a material that retains its robustness while providing specified interactions depending on the contaminant of choice.POPs raise opportunities to improve current or enable new technologies to achieve safer water. In this Account, we describe some of our efforts toward the exploitation of the unique properties of POPs for improving water purification by answering key questions and proposing research opportunities. The design strategies and principles involved for functionalizing POPs include the following: increasing the density and flexibility of the chelator to enhance their cooperation, introducing the secondary sphere modifiers to reinforce the primary binding, and enforcing the orientation of the ligands in the pore channel to increase the accessibility and cooperation of the functionalities. For each strategy, we first describe its chemical basis, followed by presenting examples that convey the underlying concepts, giving rise to functional materials that are beyond the traditional ones, as demonstrated by radionuclide sequestration, heavy metal decontamination, and oil-spill cleanup. Our endeavors to explore the applicability of POPs to deal with these high-priority contaminants are expected to impact personal consumer water purifiers, industrial wastewater management systems, and nuclear waste management. In our view, more exciting will be new applications and new examples of the functionalization strategies made by creatively merging the strategies mentioned above, enabling increasingly selective binding and efficiency and ultimately promoting POPs for practical applications to enhance water security.

Efficient and Selective Methane Borylation Through Pore Size Tuning of Hybrid Porous Organic-Polymer-Based Iridium Catalysts

As a new energy source that could replace petroleum, the global reserves of methane hydrate (combustible ice) are estimated to be approximately 20 000 trillion cubic meters. A large amount of methane hydrate has been found under the seabed, but the transportation and storage of methane gas far from coastlines are technically unfeasible and expensive. The direct conversion of methane into value-added chemicals and liquid fuels is highly desirable but remains challenging. Herein, we prepare a series of iridium complexes based on porous polycarbazoles with high specific areas and good thermochemical stabilities. Through structure tuning we optimized their catalytic activities for the selective monoborylation of methane. One of these catalysts (CAL-3-Ir) can produce methyl boronic acid pinacol ester (CH₃ Bpin) in 29 % yield in 9 h with a turnover frequency (TOF) of approximately 14 h^-1 . Because its pore sizes favor monoborylated products, it has a high chemoselectivity for monoborylation (CH₃ Bpin:CH₂ (Bpin)₂ =16:1).

Porous metal-metalloporphyrin gel as catalytic binding pocket for highly efficient synergistic catalysis

Synergistic catalysis occurring in an enzyme pocket shows enhanced performance through supramolecular recognition and flexibility. This study presents an aerogel capable of similar function by fabricating a gel catalyst with hierarchical porosity. Here, the as-prepared Co-MMPG, a Co(II) metal-metalloporphyrin gel, maintains enough conformational flexibility and features a binding pocket formed from the co-facial arrangement of the porphyrin rings, as elucidated through the combined studies of solid-state NMR and X-ray absorption near-edge structure (XANES). The cooperativity between two Co(II) sites within the defined nanospace pocket facilitates the binding of different substrates with a favourable geometry thereby rendering Co-MMPG with excellent performance in the context of synergistic catalysis, especially for the kinetic control stereoselective reactions. Our work thus contributes a different enzyme-mimic design strategy to develop a highly efficient heterogeneous catalyst with high chemo/stereo selectivity.

Synergistic catalysis occurring in an enzyme pocket shows enhanced performance through supramolecular recognition and flexibility. Here the authors design an enzyme-mimic strategy to develop a Co(II) metal-metalloporphyrin gel with excellent synergistically catalytic performance and chemo/stereo selectivity.

Porous Polymers as Multifunctional Material Platforms toward Task-Specific Applications

Exploring advanced porous materials is of critical importance in the development of science and technology. Porous polymers, being famous for their all-organic components, tailored pore structures, and adjustable chemical components, have attracted an increasing level of research interest in a large number of applications, including gas adsorption/storage, separation, catalysis, environmental remediation, energy, optoelectronics, and health. Recent years have witnessed tremendous research breakthroughs in these fields thanks to the unique pore structures and versatile skeletons of porous polymers. Here, recent milestones in the diverse applications of porous polymers are presented, with an emphasis on the structural requirements or parameters that dominate their properties and functionalities. The Review covers the following applications: i) gas adsorption, ii) water treatment, iii) separation, iv) heterogeneous catalysis, v) electrochemical energy storage, vi) precursors for porous carbons, and vii) other applications (e.g., intelligent temperature control textiles, sensing, proton conduction, biomedicine, optoelectronics, and actuators). The key requirements for each application are discussed and an in-depth understanding of the structure-property relationships of these advanced materials is provided. Finally, a perspective on the future research directions and challenges in this field is presented for further studies.

Enhanced optomechanical properties of mechanochemiluminescent poly(methyl acrylate) composites with granulated fluorescent conjugated microporous polymer fillers

With the combination of mechanochemiluminescence from 1,2-dioxetane coupled polymers and conjugated microporous polymer nanosheets, a new kind of filling-type mechanolumninescent polymer composite was developed.

With the combination of mechanochemiluminescence from 1,2-dioxetane coupled polymers and granulated conjugated microporous polymer (CMP) nanosheets, a new kind of filling-type mechanolumninescent polymer composite was developed. Herein, polymeric 1,2-dioxetane performed as an autoluminescent probe of chain scission. Besides benefiting from their excellent optical properties and good interfacial compatibility with poly(methyl acrylate) (PMA) media, two stable and fluorescent CMP nanosheets were prepared and dispersed in crosslinked PMA, which can serve as effective energy acceptors and reinforcing nano-fillers. These polymer nanocomposites present both reinforced mechanical strength and mechanochemiluminescence, and offer exciting opportunities to study the failure process of polymer nanocomposites with unprecedented temporal and spatial resolution.

Variations in Surface Morphologies, Properties, and Electrochemical Responses to Nitro-Analyte by Controlled Electropolymerization of Thiophene Derivatives

Herein, we reported the fabrication of conjugated microporous polymer (CMP) films based on three thiophene derivatives using a one-step templateless electropolymerization in dichloromethane without any surfactants. The formation of hydrophilic or hydrophobic films with specific morphology is a comprehensive result of the polymerization sites in each monomer, the polymerization rate, and the gas bubble produced in situ during the polymerization process, which can be easily controlled by the experimental conditions, such as electropolymerization method, electrolyte, and "trace water" existed in the organic solvent. Moreover, the electrochemical reduction of metronidazole as a prototypical nitro-analyte at CMP-modified glassy carbon (GC) electrode shows remarkably increased current response compared to nonmodified GC electrode. The process is demonstrated to be typical adsorption-controlled, and the hydrophobic surface of the electrode coating film is more favorable to the absorption and thus reduction of metronidazole. This work provides a new perspective and a breakthrough point for the application of CMPs in the electrochemical sensors.

Hard-template synthesis of micro-mesoporous organic frameworks with controlled hierarchicity

A hard-template synthesis strategy has been developed to prepare hierarchically porous organic frameworks. The prepared materials exhibit uniform micropores and ordered mesopores.

Synthesis of a palladium acetylide-based tubular microporous polymer monolith via a self-template approach: a potential precursor of supported palladium nanoparticles for heterogeneous catalysis

A monolithic, palladium acetylide-based conjugated microporous polymer, Pd-CMP, was synthesized from a palladium dichloride and a trialkyne. The polymerization proceeded in two different ways, the dehydrohalogenation reaction between the alkyne and the palladium halide and the homocoupling reaction of the alkyne. Pd-CMP had a rigid hollow tubular structure. The in situ formed crystalline triethylammonium chloride (TEACl) rod played a critical role in the formation of the tubular morphology as a template. Through the attachment of the polymer particles to the surface of the rod and their reactions with soluble alkynes, a core–shell structure with a TEACl core and a polymer shell formed. The TEACl core was removed by washing with methanol to yield a hollow polymer tube. Pd-CMP showed a hierarchical pore structure and reversible compressibility. Supported Pd nanoparticles were prepared by one-step thermolysis of Pd-CMP as a heterogeneous catalyst. The average diameters of NPs in the products thermolyzed at 300 (Pd-CMP₃₀₀) and 500 °C (Pd-CMP₅₀₀) were 2.6 and 4.1 nm, respectively. Pd-CMP₃₀₀ was used in the heterogeneous catalysis of the 4-nitrophenol reduction reaction and Suzuki–Miyaura coupling between iodobenzene and phenylboronic acid. The reaction yields were higher than 95%. The catalyst could be used for a flow reaction and easily recycled without significant activity loss.

A monolithic palladium acetylide-based tubular microporous polymer was synthesized as a promising precursor of a palladium heterogeneous catalyst.

Preparation of a Sulfur-Functionalized Microporous Polymer Sponge and In Situ Growth of Silver Nanoparticles: A Compressible Monolithic Catalyst

We report a compressible monolithic catalyst based on a microporous organic polymer (MOP) sponge. The monolithic MOP sponge was synthesized via Sonogashira-Hagihara coupling reaction between 1,4-diiodotetrafluorobenzene and 1,3,5-triethynylbenzene in a cosolvent of toluene and TEA (2:1, v/v) without stirring. The MOP sponge had an intriguing microstructure, where tubular polymer fibers having a diameter of hundreds of nanometers were entangled. It showed hierarchical porosity with a Brunauer-Emmett-Teller (BET) surface area of 512 m² g^-1. The MOP sponge was functionalized with sulfur groups by the thiol-yne reaction. The functionalized MOP sponge exhibited a higher BET surface area than the MOP sponge by 13% due to the increase in the total pore and micropore volumes. A MOP sponge-Ag heterogeneous catalyst (S-MOPS-Ag) was prepared by in situ growth of silver nanoparticles inside the sulfur-functionalized MOP sponge by the reduction of Ag⁺ ions. The catalytic activity of S-MOPS-Ag was investigated for the reduction reaction of 4-nitrophenol in an aqueous condition. When S-MOPS-Ag was compressed and released during the reaction, the rate of the reaction was considerably increased. S-MOPS-Ag was easily removed from the reaction mixture owing to its monolithic character and was reused after washing and drying.

β-FeOOH Nanorods/Carbon Foam-Based Hierarchically Porous Monolith for Highly Effective Arsenic Removal

Arsenic pollution in waters has become a worldwide issue, constituting a severe hazard to whole ecosystems and public health worldwide. Accordingly, it is highly desirable to design high-performance adsorbents for arsenic decontamination. Herein, a feasible strategy is developed for in situ growth of β-FeOOH nanorods (NRs) on a three-dimensional (3D) carbon foam (CF) skeleton via a simple calcination process and subsequent hydrothermal treatment. The as-fabricated 3D β-FeOOH NRs/CF monolith can be innovatively utilized for arsenic remediation from contaminated aqueous systems, accompanied by remarkably high uptake capacity of 103.4 mg/g for arsenite and 172.9 mg/g for arsenate. The superior arsenic uptake performance can be ascribed to abundant active sites and hydroxyl functional groups available as well as efficient mass transfer associated with interconnected hierarchical porous networks. In addition, the as-obtained material exhibits exceptional sorption selectivity toward arsenic over other coexisting anions at high levels, which can be ascribed to strong affinity between active sites and arsenic. More importantly, the free-standing 3D porous monolith not only makes it easy for separation and collection after treatment but also efficiently prevents the undesirable potential release of nanoparticles into aquatic environments while maintaining the outstanding properties of nanometer-scale building blocks. Furthermore, the monolith absorbent is able to be effectively regenerated and reused for five cycles with negligible decrease in arsenic removal. In view of extremely high adsorption capacities, preferable sorption selectivity, satisfactory recyclability, as well as facile separation nature, the obtained 3D β-FeOOH NRs/CF monolith holds a great potential for arsenic decontamination in practical applications.

Anchoring Triazole-Gold(I) Complex into Porous Organic Polymer To Boost the Stability and Reactivity of Gold(I) Catalyst

Stability and reactivity have been recognized as some critical issues for gold(I) catalysts. Such issues can be well-circumvented by anchoring the gold(I) complex onto the backbones of porous organic polymer (POP) followed by coordination with a triazole ligand as illustrated in the present work via a series of gold(I)-catalyzed reactions. In this strategy, 1,2,3-triazole was used as the special "X-factor" to avoid the formation of solid AgCl involved in typical gold-activation processes. The catalyst could be readily recycled without loss of reactivity. Moreover, compared with the PPh₃-modified polystyrene beads, the POP support was advantageous by providing high surface area, hierarchical porosity, and better stabilization of cations. In some cases, significantly improved reactivity was observed, even more so than using the homogeneous system, which further highlighted the great potential of this heterogeneous gold catalyst.

Shaping of Metal-Organic Frameworks: From Fluid to Shaped Bodies and Robust Foams

The applications of metal-organic frameworks (MOFs) toward industrial separation, catalysis, sensing, and some sophisticated devices are drastically affected by their intrinsic fragility and poor processability. Unlike organic polymers, MOF crystals are insoluble in any solvents and are usually not thermoplastic, which means traditional solvent- or melting-based processing techniques are not applicable for MOFs. Herein, a continuous phase transformation processing strategy is proposed for fabricating and shaping MOFs into processable fluids, shaped bodies, and even MOF foams that are capable of reversible transformation among these states. Based on this strategy, a cup-shaped Cu-MOF composite and hierarchically porous MOF foam were developed for highly efficient catalytic C-H oxidation (conv. 76% and sele. 93% for cup-shaped Cu-MOF composite and conv. 92% and sele. 97% for porous foam) with ease of recycling and dramatically improved kinetics. Furthermore, various MOF-based foams with low densities (<0.1 g cm(-3)) and high MOF loadings (up to 80 wt %) were obtained via this protocol. Imparted with hierarchically porous structures and fully accessible MOFs uniformly distributed, these foams presented low energy penalty (pressure drop <20 Pa, at 500 mL min(-1)) and showed potential applications as efficient membrane reactors.

Polyamino amphiphile mediated support of platinum nanoparticles on polyHIPE as an over 1500-time recyclable catalyst

For supported metal nanoparticles, the ligand/support is crucial to their catalytic activity, stability and recyclability.