Conjugated Microporous Polymers Research Articles

Piezocatalytic Performances of Conjugated Microporous Polymers with Donor–Acceptor Structures for Overall Water Splitting

Piezocatalytic Performances of Conjugated Microporous Polymers with Donor–Acceptor Structures for Overall Water Splitting

Doping Ferrocene-Based Conjugated Microporous Polymers with 7,7,8,8-Tetracyanoquinodimethane for Efficient Photocatalytic CO2 Reduction.

The design and synthesis of organic photocatalysts remain a great challenge due to their strict structural constraints. However, this could be mitigated by achieving structural flexibility by constructing permanent porosity into the materials. Conjugated microporous polymers (CMPs) are an emerging class of porous materials with an amorphous, three-dimensional network structure, which makes it possible to integrate the elaborate functional groups to enhance photocatalytic performance. Here, we report the synthesis of a novel CMP, named TAPFc-TFPPy-CMP, constructed by 1,1'3,3'-tetra(4-aminophenyl)ferrocene (TAPFc) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) monomers. The integration of the p-type dopant 7,7,8,8-tetracyanoquinodimethane (TCNQ) into the TAPFc-TFPPy-CMP improved the light adsorption performance, leading to a decrease in the optical bandgap from 2.00 to 1.43 eV. The doped CMP (TCNQ@TAPFc-TFPPy-CMP) exhibited promising catalytic activity in photocatalytic CO2 reduction under visible light, yielding 546.8 μmol g-1 h-1 of CO with a selectivity of 96% and 5.2 μmol g-1 h-1 of CH4. This represented an 80% increase in the CO yield compared to the maternal TAPFc-TFPPy-CMP. The steady-state photoluminescence (PL) and fluorescence lifetime (FL) measurements reveal faster carrier separation and transport after the doping. This study provides guidance for the development of organic photocatalysts for the utilization of renewable energy.

2-Pyran-4-Ylidene Malononitrile Based Conjugated Microporous Polymers as Metal-Free Heterogeneous Photocatalysts for Organic Synthesis.

Photoactive conjugated microporous polymers (CMPs) as heterogeneous photocatalysts provide a sustainable alternative to classical metal-based semiconductor photosensitizers. However, previously reported CMPs are typically synthesized through metal catalyzed coupling reactions, which bears product separation, but also increases the price of materials. Herein, a new type of sp2 carbon linked DCM-CMPs are successfully designed and synthesized by organic base catalyzed Knoevenagel reaction using 2,6-Dimethyl-4H-pyran-4-ylidene-malononitrile and aromatic polyaldehydes as monomers. The new polymers feature inherent porosity, excellent stability, and fully π-conjugated skeleton with broad visible-light absorption. They effectively induce the synthesis of benzimidazole compounds under light irradiation, and exhibit wide substrate adaptability with outstanding recyclability.

Construction of cationic conjugated microporous polymers containing pyrene units through post-cationic modification for enhanced antibacterial performance

BackgroundThe development of effective antibacterial agents with minimal cytotoxicity to human cells is a subject of great interest. Conjugated microporous polymers (CMPs) are a rapidly expanding and significant class of porous organic polymers. They are distinguished by their robust microporous architecture and π-conjugated framework. The molecular-level control over the pore structure and chemical composition of CMPs allows for precise customization to fulfill particular requirements. MethodsWe synthesized a cationic conjugated microporous polymer named Pyr-T-DPM Me CMP. This was achieved through post-synthetic modification of a pyrene-T-linked conjugated microporous polymer, Pyr-T-DPM CMP, formed via the Sonogashira coupling reaction of ethynyl pyrene (Pyr-T) and 2,5-dibromopyrimidine (Pyrimidine-Br2). The comprehensive analysis involved various techniques, including Fourier transform infrared (FTIR) spectroscopy, N2 adsorption/desorption isotherm, 13C solid-state NMR, X-ray photoelectron spectroscopy (XPS), thermogravimetry, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Significant findingsThe antimicrobial efficacy of the newly synthesized CMPs was tested against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria. Due to the formation of N-methylpyrimidinium salts after quaternization, the cationic Pyr-T-DPM Me CMP exhibited enhanced bactericidal effectiveness against S. aureus compared to Pyr-T-DPM CMP, which lacked a positive charge. The viability of bacteria decreased with increasing concentrations of Pyr-T-DPM Me CMP, reaching maximum antimicrobial effectiveness at a concentration of 5 mg mL−1. To assess their impact on cell compatibility, we evaluated the cytotoxic effects on L929 cell fibroblasts, revealing minimal cytotoxicity towards L929 cells. Inspired by the superior antibacterial characteristics and exceptionally low toxicity of Pyr-T-DPM Me CMP, the novel cationic CMP developed in this study holds potential for application as beneficial antibacterial agent in the fields of environmental engineering and healthcare.

Positional isomerism engineering toward minimizing exciton binding energy in sulfone copolymers for enhanced uranyl photoreduction

Conjugated microporous polymers (CMPs) have emerged as promising platforms for photocatalytic separation and enrichment of radionuclides. However, the development of CMPs with efficient exciton dissociation and free charge generation is still highly hindered by their high exciton binding energy (Eb). Herein, for the first time, three sulfone-containing CMPs are fabricated to regulate Eb by position isomerism of altering linkage sites. Temperature-dependent photoluminescence spectra reveals that ECUT-3,7-SO with 3,7-site linkage achieves a diminished Eb of 40.1 meV. DFT calculation complementally demonstrate that the Eb is related to its strongly polarized electric field and large conjugation degree, which can be easily regulated via position isomerism of its building blocks. Among the three, ECUT-3,7-SO exhibits a completely conjugated structure and a large molecular dipole moment, thus significantly reducing the Eb. As a result, ECUT-3,7-SO exhibits the highest photoreduction uranium rate constant (k, T = 298.15 K) of 0.081 min−1, and the maximum uranium extraction capacity of 918.0 mg g−1 under visible-light irradiation. This work highlights the importance of positional isomerization to the development of low exciton binding energy photocatalyst for uranium resource field.

Selective oxidation of β-keto ester modulated by the d-band centers in D-A conjugated microporous metallaphotoredox catalysts containing M−salen (M[dbnd]Zn, Cu and Co) and triazine monomers

Photocatalytic selective oxidation plays an important role in developing green chemistry. However, it is challenging to design an efficient photocatalyst for controlling the selectivity of photocatalytic oxidation reaction and exploring its detailed mechanism. Here, we synthesized three conjugated microporous polymers (CMPs) with D-A structures, named M−SATE−CMPs (MZn, Cu and Co), with different d-band centers based on different metal centers, resulting in the discrepancy in adsorption and activation capacities for the reactants, which produces the selectivity of β-keto esters being catalyzed into α-hydroperoxide β-keto esters (ROOH) or to α-hydroxyl β-keto esters (ROH). Density functional theory (DFT) calculations also demonstrate that the adsorption and activation capacities of the metal active centers in M−SATE−CMPs (MZn, Cu and Co) for ROOH are the key factors to influence the photocatalytic selective oxidation of β-keto ester. This study provides a promising strategy for designing a metallaphotoredox catalyst whose photocatalytic selectivity depends on the d-band center of metal site in the catalyst.

Solvent-free synthesis of polytriazine-bithiophene for excellent lithium/sodium-ion storage

A conjugated microporous polymer (CMP) combining triazine and bithiophene units in the same framework is synthesized by a facile solvent-free one-pot method and employed as an anode material for lithium/sodium-ion batteries (LIBs/SIBs). It exhibits a large rate capability with a high reversible capacity for LIBs after activation, e.g., 1014 mAh g−1 at 0.1 A g−1 and 486 mAh g−1 at a current density of 5 A g−1 with outstanding cycling stability. Meanwhile, it delivers perfect electrochemical properties for SIBs, featuring high reversible specific capacities of 425/260/156 mAh g−1 at 0.1/1/5 A g−1. Especially, the CMP even outstrips most crystalline covalent organic frameworks (COFs) as SIB anodes at high current density. The lithium and sodium storage mechanisms of the CMP structural unit involve 11-electron redox reactions with four and three-step structure evolutions respectively, as follows from density functional theory calculations. The reported study demonstrates the CMP with redox-active electron donating units via triazine bonding as a promising electrode material for next-generation green sustainable energy storage devices.

Photothermal Conversion Porous Organic Polymers: Design, Synthesis, and Applications.

Solar energy is a primary form of renewable energy, and photothermal conversion is a direct conversion process with tunable conversion efficiency. Among various kinds of photothermal conversion materials, porous organic polymers (POP) are widely investigated owing to their controllable molecular design, tailored porous structures, good absorption of solar light, and low thermal conductivity. A variety of POP, such as conjugated microporous polymers (CMP), covalent organic frameworks (COF), hyper-crosslinked porous polymers (HCP), polymers of intrinsic microporosity (PIM), porous ionic polymers (PIP), are developed and applied in photothermal conversion applications of seawater desalination, latent energy storage, and biomedical fields. In this review, a comprehensive overview of the recent advances in POP for photothermal conversion is provided. The micro molecular structure characteristics and macro morphology of POP are designed for applications such as seawater desalination, latent heat energy storage, phototherapy and photodynamic therapy, and drug delivery. Besides, a probe into the underlying mechanism of structural design for constructing POP with excellent photothermal conversion performance is methodicalized. Finally, the remaining challenges and prospective opportunities for the future development of POP for solar energy-driven photothermal conversion applications are elucidated.

Confined synthesis of conjugated microporous polymers for selective photocatalytic oxidation of amines

Photocatalytic oxidative coupling of amines is considered a mild, efficient, and sustainable strategy for the synthesis of imines. As a versatile organic semiconductor, conjugated microporous polymers (CMPs) are attractive in photocatalysis areas due to the diversity of their polymeric monomers. Herein, we report that in addition to the design of monomers, size-confined polymerization is also a feasible strategy to modulate the structure and photocatalysis properties of CMPs. We adopted dibromopyrazine as polymeric units to prepare pyrazine-involved hollow spherical CMPs (H-PyB) using a template method and successfully performed size-confined polymerization of hollow samples by resizing the templates. Interestingly, the small confinement space induced the formation of CMPs with better conjugate extensibility, resulting in enhanced conductivity, narrowed bandgaps, improved photoelectric performance, etc. As a result, small-sized H-PyB CMPs had superior activity for the photocatalytic oxidation of amines. Particularly, the smallest H-PyB CMPs that we designed in the present work exhibited excellent performance for the photocatalytic coupling oxidation of amines. When using benzylamine as a model substrate, the yield of the corresponding imine reached ∼ 113 mmol·g−1·h−1, accompanied by almost 100 % selectivity. Furthermore, the as-designed confined samples exhibited stable photocatalytic activity as well as good applicability for oxidative coupling of different amines. This work not merely reports a kind of CMP photocatalysts with excellent performance for the imine coupling oxidation but also proposes an alternative strategy for constructing high-performance organic photocatalysts by size-confined synthesis.

Electropolymerization of Preferred-Oriented Conjugated Microporous Polymer Films for Enhanced Fluorescent Sensing.

High-quality conjugated microporous polymer (CMP) films with orientation and controlled structure are extremely desired for applications. Here, we report the effective construction of CMP 3D composite films (pZn/PTPCz) with a controlled porosity structure and preferred orientation using the template-assisted electropolymerization (EP) approach for the first time. The structure of pZn/PTPCz composite thin films and nitrophenol sensing performance were thoroughly studied. When compared to the control CMP film made on flat indium tin oxide (ITO) substrates, the as-prepared pZn/PTPCz composite films showed significantly enhanced fluorescent intensity and much better sensing performance for the model explosive. This was attributed to the metal-enhanced fluorescence (MEF) of porous nanostructured zinc (pZn) and the additional macroporosity of the pZn/PTPCz composite films. This work provides a feasible approach for creating oriented 3D CMP-based thin films for advanced applications.

Benzotrithiophene conjugated microporous polymer photocatalysts for selective aerobic sulfoxidation driven by green light

Porous organic materials with permanent skeletons, highly delocalized π–π conjugations, and stable chemical bonds have an excellent potential for visible light photocatalysts. Essentially, the efficiency depends on the building blocks, among which benzotrithiophene, electron-rich and planar, is highly favored. In this work, starting with benzo[1,2-b:3,4-b′:5,6-b′′]trithiophene-2,5,8-tricarbaldehyde (BTT), 1,4-phenylenediacetonitrile (PDAN) and 1,4-phenylenediamine (PDA) are adopted to synthesize two porous organic materials with vinylene and imine linkages, respectively. The lowly reversible vinylene only allows the formation of a conjugated microporous polymer (CMP), BTT-PDAN-CMP. In contrast, the highly reversible imine enables the construction of a covalent organic framework (COF), BTT-PDA-COF. Despite being amorphous, BTT-PDAN-CMP, with robust sp2-carbon skeletons, displays superior photoelectric performance than BTT-PDA-COF due to the enhanced electron transfer of vinylene linkage, which is beneficial to be an efficient photocatalyst. Therefore, it is shown that BTT-DPAN-CMP photocatalyst demonstrates better efficiency than BTT-PDA-COF for selective aerobic sulfoxidation driven by green light. This work underlines the importance of rational design for porous organic materials as selective visible light photocatalysts.

Powders to Thin Films: Advances in Conjugated Microporous Polymer Chemical Sensors.

Chemical sensing of harmful species released either from natural or anthropogenic activities is critical to ensuring human safety and health. Over the last decade, conjugated microporous polymers (CMPs) have been proven to be potential sensor materials with the possibility of realizing sensing devices for practical applications. CMPs found to be unique among other porous materials such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) due to their high chemical/thermal stability, high surface area, microporosity, efficient host-guest interactions with the analyte, efficient exciton migration along the π-conjugated chains, and tailorable structure to target specific analytes. Several CMP-based optical, electrochemical, colorimetric, and ratiometric sensors with excellent selectivity and sensing performancewere reported. This review comprehensively discusses the advances in CMP chemical sensors (powders and thin films) in the detection of nitroaromatic explosives, chemical warfare agents, anions, metal ions, biomolecules, iodine, and volatile organic compounds (VOCs), with simultaneous delineation of design strategy principles guiding the selectivity and sensitivity of CMP. Preceding this, various photophysical mechanisms responsible for chemical sensing are discussed in detail for convenience. Finally, future challenges to be addressed in the field of CMP chemical sensors are discussed.

Composite Flame Retardants Based on Conjugated Microporous Polymer Hollow Nanospheres with Excellent Flame Retardancy.

The development of polymer materials with excellent flame retardancy has been paid increasing attention for their valuable applications in saving energy in modern architecture. Herein, conjugated microporous polymers hollow nanospheres (CMPs-HNS) were prepared by Sonogashira-Hagihara cross-coupling reaction with 1,3,5-triacetylenebenzene, 3-amino-2,6-dibromopyridine, and 2,4,6-tribromoaniline as building blocks using SiO2 nanoparticles as hard templates. To enhance the flame-retardant performance of the CMPs-HNS, antimony pentoxide solution (Sb2O5) and bisphenol A-bis (diphenyl phosphate) (BDP) were coated onto the as-prepared CMP-HNS (CMPs-HNS-BSb) by a simple immersion method. The peak heat release (pHRR) from microscale combustion colorimeter (MCC) of CMPs-HNS-BSb was 76.5 and 73.05 W g-1, respectively. By introducing CMPs-HNS-BSb into the epoxy resin (EP) matrix, the CMP2-HNS-BSb/EP (0.5) composites show that the pHRR values were 809.3 and 645.2 kW m-2, reduced by 21% as measured by conical calorimetry (CC), and total heat release (THR) reduced by 29.7%, going from 101 to 70.8 MJ/m2 when compared to the pure sample. Besides, total smoke production (TSP) reduced about 23.7%. The hollow structure can enhance the thermal insulation performance. As measured, the thermal conductivity of CMP1-HNS-BSb and CMP2-HNS-BSb is 0.044 and 0.048 W m-1 K-1. Based on the advantages of simple manufacture, superior thermal insulation, and flame retardancy, our CMPs-HNS-BSb/EP composites may find useful applications in various aspects such as building energy saving in future development.

Utilizing Hairy Hollow Conjugated Microporous Polymers and Native Enzymes for Precise Aerobic Photocatalysis Under Near‐Infrared Wavelengths

AbstractUtilizing photoregenerated cofactors in conjunction with enzymes in a sequential manner presents an effective approach for the synthesis of targeted compounds in gentle reaction conditions. Nevertheless, the integration of enzymes and photocatalysts has faced challenges due to the swift breakdown of biomaterials caused by high‐energy or blue lights and photoinduced reactive oxygen species, leading to the denaturation and deactivation of enzymatic materials. This study details the deliberate development and production of hairy hollow conjugated microporous polymers (S‐hPrTZ‐P HCMPs), achieved via Sonogashira–Hagihara coupling on SiO2 templates, followed by sulfonation, polymer grafting and ultimately eliminating the SiO2 cores. This technique leverages the distinctive characteristics of low‐energy near‐infrared light, such as its superior penetration ability, to effectively regenerate the enzymatic cofactor NAD+ from NADH. It can accomplish this feat even when faced with synthetic or biological barriers that are impermeable to visible light. Simultaneously, photogenerated reactive oxygen species are captured and neutralized by the hydrophilic polymer brushes, safeguarding the integrity of the enzymatic material. The adaptability of S‐hPrTZ‐P with photocatalytic properties is showcased alongside glucose 1‐dehydrogenase and glycerol dehydrogenase. This structure and morphology‐controlled strategy offers a promising pathway for various enzymatic photobiocatalysis employing stable, efficient, and reusable hairy HCMPs.

Porphyrin-Based Conjugated Microporous Polymer Loaded with Nanoscale Zerovalent Iron for the Degradation of Organic Pollutants under Visible Light.

The degradation of organic dye from waterbodies is of great significance for clean production and environmental remediation. Herein, two porphyrin-based conjugated microporous polymers (CMPs) loaded with nanoscale zerovalent iron (named as Por-CMPs-1-2@nZVI) were successfully fabricated by Sonogashira-Hagihara coupling reactions and the liquid-phase method. The as-synthesized Por-CMPs-1-2@nZVI composites were characterized by various means of analysis, and it was confirmed that Por-CMPs-1-2 loaded with nZVI had good photocatalytic performance. Calculated by ultraviolet-visible spectrum, the band-gap energies of Por-CMPs-1@nZVI and Por-CMPs-2@nZVI were 1.45 and 1.32 eV, respectively, indicating that both can be activated by visible light. The photodegradation of organic dye experiments demonstrated that Por-CMPs-2@nZVI degraded 98.0% of 10 ppm Methylene Blue (MB) within 150 min, which is higher than that of Por-CMPs-1-2 and Por-CMPs-1@nZVI. The experiment of active substance capture and mechanism of ESR confirmed that superoxide anion and hydroxyl radical were the primary valid substances in the photodegradation process of MB. In addition, the preparation of membrane materials was shown to be a successful strategy to realize engineered scale-up production.

Ultra-stable hollow nanotube conjugated microporous polymer incorporating fluorenyl moieties for Co-capture of PM and CO2

Conjugated microporous polymers have a highly delocalized π-π conjugated porous skeleton connected by covalent bonds, which can combine their excellent stability with high adsorption, in order to be applied to the study of co-capture of harmful particulate matter (PM) and carbon dioxide (CO2) under high temperature and high humidity conditions. In this paper, fluorene-based coupled conjugated microporous polymers (D-CMPs) with functionalized hollow nanotubes and abundant microporous structures were proposed. Through mechanism exploration and molecular electrostatic potential (MESP) calculation, the capture efficiency, adsorption capacity and selectivity of PM and CO2 in the waste gas stream of carbon-based combustion were analyzed. The results indicate that D-CMPs, with their rigid carbon-based π-conjugated framework, exhibit excellent tolerance under prolonged high-humidity conditions, with a capture efficiency exceeding 99.87% for PM0.3 and exceeding 99.99% for PM2.5. Meanwhile, based on its chemical/thermal stability, it can realize the recycling of adsorption-regeneration. On this basis, the "slip effect" induced by the open three-dimensional hierarchical porous structure of D-CMPs significantly enhances airflow dispersion and improves gas throughput (with a minimal permeation resistance of only 15 Pa). At a pressure of 1 bar and a temperature of 273.15 K, D-CMP-2 exhibited a CO2 adsorption capacity of up to 2.69 mmol g−1. The fitting results of three isothermal adsorption models demonstrate that D-CMPs exhibit an outstanding equilibrium selectivity towards CO2. Therefore, prior to the widespread adoption of low-carbon and clean energy technologies, porous solid materials exhibiting excellent structural stability, equilibrium selectivity, environmental tolerance, and high adsorption capacity emerge as optimal candidates for the treatment of industrial waste gases.

An Appraisal for Providing Charge Transfer (CT) Through Synthetic Porous Frameworks for their Semiconductor Applications.

In recent years, there has been considerable focus on the development of charge transfer (CT) complex formation as a means to modify the band gaps of organic materials. In particular, CT complexes alternate layers of aromatic molecules with donor (D) and acceptor (A) properties to provide inherent electrical conductivity. In particular, the synthetic porous frameworks as attractive D-A components have been extensively studied in recent years in comparison to existing D-A materials. Therefore, in this work, the synthetic porous frameworks are classified into conjugated microporous polymers (CMPs), covalent organic frameworks (COFs), and metal-organic frameworks (MOFs) and compare high-quality materials for CT in semiconductors. This work updates the overview of the above porous frameworks for CT, starting with their early history regarding their semiconductor applications, and lists CT concepts and selected key developments in their CT complexes and CT composites. In addition, the network formation methods and their functionalization are discussed to provide access to a variety of potential applications. Furthermore, several theoretical investigations, efficiency improvement techniques, and a discussion of the electrical conductivity of the porous frameworks are also highlighted. Finally, a perspective of synthetic porous framework studies on CT performance is provided along with some comparisons.

Synthesis of conjugated microporous polymers rich in sulfonic acid groups for the highly efficient adsorption of Cs+

Conjugated microporous polymers (CMPs) with extended π-conjugated systems and permanent microporous scaffolders have broad application prospects in the treatment of radionuclides in nuclear wastewater. Herein, the Sonogashira–Hagihara coupling process was employed to generate three CMPs, called CMP1–3. CMP1S–3S with different degrees of sulfonation were produced and employed for Cs+ ion adsorption by adjusting the sulfonation time using chlorosulfonic acid as the sulfonating agent. This is the first attempt to apply CMPs containing sulfonic acid groups to Cs+ ion adsorption, which show excellent adsorption properties. CMP1S-48 with the highest surface sulfonic acid group density exhibited the fastest adsorption rate, and it reached adsorption equilibrium on Cs+ ion in an aqueous solution under 1 min. The adsorption process corresponded to the Freundlich isotherm model of multilayer adsorption, with an adsorption capacity of up to 288.1 mg g−1. Compare with CMP2S-48 and CMP3S-48, CMP1S-48 with more sulfonic acid groups shows the highest adsorption capacity. Moreover, the selectivity of CMP1S-48 adsorbing Cs+ ion was exceeded high. Notably, the adsorption mechanism of Cs+ ion by CMP1S–3S involved ion exchange with H+ in the sulfonic acid groups, as well as its complexation and electrostatic attraction with the sulfonic acid groups. This work opens up a new way for CMPs rich in sulfonic acid groups to treat Cs+ ion-contaminated water sources.

Self‐Floating Photocatalytic System for Highly Efficient Hydrogen Peroxide Production and Organic Synthesis on Carbon Dots Decorated Conjugated Microporous Polymer

AbstractPhotocatalytic oxygen (O2) reduction to hydrogen peroxide (H2O2) is considered to be a promising method for energy storage. However, it suffers from the rapid recombination of carriers, the limited solubility and slow diffusion of O2, and the self‐decomposition of H2O2 in traditional diphase systems. Here, a self‐floating carbon dots/conjugated microporous polymer (CDs/CMP) photocatalytic system is established for H2O2 production and organic synthesis. Due to the D–π–A structure, porous structure, and hydrophobicity, CMP induced the intramolecular charge transfer, exposed abundant reaction sites, and enhanced O2 adsorption. CDs act as “bridges” for electron transmission and regulate the surface hydrophobicity of CMP, further improving charge transfer and optimizing the reaction interface. CDs/CMP system exhibits a high H2O2 production of 8542.6 µmol g−1 h−1 and concurrent furoic acid production at 2.22 mm h−1. This H2O2 production rate is ≈90% higher than that in the diphase system, exceeding all previously reported photocatalysts in triphase systems. Notably, the CDs/CMP system achieves the relative separation of the photocatalysts and H2O2, suppressing the generated H2O2 self‐decomposition. Theoretical calculations and in situ characterizations reveal the mechanism of H2O2 and furoic acid evolution. This self‐floating system provides insights into exploring the application of metal‐free photocatalysts in heterogeneous reactions.

Conjugated microporous polymer chitosan hybrid materials for enhanced pollutant removal

Highly tailorable adsorbents are the key to addressing specialized pollution problems, such as the release of pharmaceuticals into our wastewaters. Conjugated microporous polymers (CMPs) pose a platform with modifiable functionality and pore system, allowing pollutant-customized adsorption. Herein novel phenanthren-dione based monomers are coupled to triethynylbenzene (TEB) forming new CMPs. These are compared with two literature-known, also TEB based CMPs regarding their adsorption properties towards the model drug diclofenac. To improve the handleability and enhance the adsorption the CMPs are integrated into chitosan gel beads, enabling simple removal using a sieve. The drying process of the beads turned out to significantly influence the swelling. Vacuum-dried beads exhibited 4–8 times higher water uptake than air-dried beads. Further, it proved beneficial to use hexanoyl modified chitosan as hybrid matrix, since it shows even further improved swelling capabilities, leading to a facilitated diffusion of the diclofenac through the chitosan matrix. This resulted in a notable enhancement of the adsorption efficiency of the CMPs, while concurrently exerting control over the adsorption process through the customization of swelling properties.