Covalent Organic Frameworks Materials Research Articles

Construction of 2D/2D Pd Metallene/COFs System with Strong Internal Electric Field for Outstanding Solar Energy Photocatalysis.

Due to the severe recombination of charge carriers, the photocatalytic activity of covalent organic frameworks (COFs) materials is limited. Herein, through simple ultrasound and stirring processes, the Pd metallene (Pde) is successfully combined with 2D COFs to form Pde/TpPa-1-COF (Pde/TPC) composites. Obviously, a strong internal electric field (IEF) is successfully formed in Pde/TPC hybrid materials, which significantly boosts the separation of photogenerated charges. In addition, the matched 2D structure of the two materials can also lead to electronic coupling effects, plentiful active sites, and shortened carrier migration paths. Thus, the Pde/TPC hybrid materials own extraordinary carrier separation ability with a longer carriers lifetime (3.3 ns for Pde/TPC and 2.7 ns for TPC), which can be proved series of photoelectrochemical and spectroscopic tests. Benefiting from the formation of IEF and the matched 2D structure, the 8% Pde/TPC demonstrates the highest photocatalytic H2 evolution efficiency, with H2 production rate reaching up to 5.85 mmolg-1h-1, which is over 25 times greater than that of pristine COFs, also exceeding that of many reported COFs-based photocatalysts. This research provides new perspectives and innovative approaches to further research on enhancing the internal electric field of COFs to promote their photocatalytic performance.

Achieving Sub-ppm Sensitivity in SO2 Detection with a Chemically Stable Covalent Organic Framework.

We report the inaugural experimental investigation of covalent organic frameworks (COFs) to address the formidable challenge of SO2 detection. Specifically, an imine-functionalized COF (SonoCOF-9) demonstrated a modest and reversible SO2 sorption of 3.5 mmol g-1 at 1 bar and 298 K. At 0.1 bar (and 298 K), the total SO2 uptake reached 0.91 mmol g-1 with excellent reversibility for at least 50 adsorption-desorption cycles. An isosteric enthalpy of adsorption (ΔHads) for SO2 equaled -42.3 kJ mol-1, indicating a relatively strong interaction of SO2 molecules with the COF material. Also, molecular dynamics simulations and Møller-Plesset perturbation theory calculations showed the interaction of SO2 with π density of the rings and lone pairs of the N atoms of SonoCOF-9. The combination of experimental data and theoretical calculations corroborated the potential use of this COF for the selective detection and sensing of SO2 at the sub-ppm level (0.0064 ppm of SO2).

Achieving Sub‐ppm Sensitivity in SO2 Detection with a Chemically Stable Covalent Organic Framework

AbstractWe report the inaugural experimental investigation of covalent organic frameworks (COFs) to address the formidable challenge of SO2 detection. Specifically, an imine‐functionalized COF (SonoCOF‐9) demonstrated a modest and reversible SO2 sorption of 3.5 mmol g−1 at 1 bar and 298 K. At 0.1 bar (and 298 K), the total SO2 uptake reached 0.91 mmol g−1 with excellent reversibility for at least 50 adsorption‐desorption cycles. An isosteric enthalpy of adsorption (ΔHads) for SO2 equaled −42.3 kJ mol−1, indicating a relatively strong interaction of SO2 molecules with the COF material. Also, molecular dynamics simulations and Møller–Plesset perturbation theory calculations showed the interaction of SO2 with π density of the rings and lone pairs of the N atoms of SonoCOF‐9. The combination of experimental data and theoretical calculations corroborated the potential use of this COF for the selective detection and sensing of SO2 at the sub‐ppm level (0.0064 ppm of SO2).

Synthesis of MOF@COF composites and study on dye adsorption properties

MOF@COF hybrid materials not only have high stability and adjustable function, but also have the characteristics of MOFs and COFs materials, which make them have important application value in the field of adsorption. This article employs 1,3,5-benzene tricarbonyl chloride and p-Phenylenediamine as covalent organic framework monomers. Through the in-situ growth of covalent organic frameworks (COF) on the surface of NH2-MIL-88(Fe) material, a novel, stable, and porous COF-on-MOF hybrid material (NH2-MIL-88(Fe)/COF) was synthesized. The structure, morphology, and performance of the hybrid material were thoroughly examined using characterization techniques, including Fourier-transform infrared spectroscopy (FT-IR), powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and thermal gravimetric analysis (TGA). Subsequently, We explored the MOF@COF hybrid material as an effective adsorbent for removing organic dyes, namely methylene blue (MB), methyl orange (MO), and crystal violet (CV). The influence of various adsorption parameters, such as adsorption time, initial dye concentration, and different pH values, on dye adsorption performance was systematically investigated. Experimental results revealed that at pH = 7, NH2-MIL-88(Fe)/COF demonstrates maximum adsorption capacities of 114 mg·g−1, 106 mg·g−1, and 102 mg·g−1 for methylene blue, methyl orange, and crystal violet, respectively. The adsorption process follows pseudo-second-order kinetics and Langmuir isotherm models. Lastly, NH2-MIL-88(Fe)/COF maintains high removal efficiency for the three dyes even after five repeated uses, establishing it as a stable and efficient adsorbent. The research findings suggest that MOF@COF hybrid materials hold promising applications in the treatment of dye-containing wastewater.

A needle-like covalent organic framework with highly accessible phenazine and π-conjugated structure for potassium storage and its reaction mechanism

Covalent organic frameworks (COFs) with features of light elements, tailored functional groups, and designable structures are regarded as promising candidates for future potassium ion batteries (PIBs), while the low electronic conductivity and intricate reaction mechanism restrict their practical application. Herein, a needle-like COF material, marked as CPT, was synthesized by an acid-catalyzed condensation reaction between cyclohexanehexone and 2,3,7,8-phenazine tetramine. It was constructed by interconnected phenazine with π-conjugated structures, displaying the advantages of rich electron delocalization, thin sheet thickness, and low dissolution in electrolytes. When applied as the anode of PIBs, the CPT anode delivered a high reversible capacity of 305 mAh g−1 at 0.1 A g−1 over 200 cycles. Besides, it also exhibited promising potential for “high-temperature” application potential by retaining a capacity of 400 mAh g−1 at 0.1 A g−1 after 100 cycles at 45 °C. Full cells with CPT anode and potassiathed organic cathode displayed good cycling and rate performances. Furthermore, the step-wise K-storage mechanism was jointly determined by in-situ characterization techniques and theoretical calculations. This study not only presents a molecular engineering approach for designing organic materials but also provides novel insights into the underlying mechanism governing potassium storage.

CuxOy Incorporated COF: A Potential Reusable Catalyst for the Synthesis of α‐Hydroxy Ketones and Oxazolidinones Under Atmospheric CO2 Pressure and Solvent‐Free Conditions

AbstractIn this present work, a newly designed metal‐oxide nanoparticle incorporated Covalent organic framework (COF), CuxOy@TFP‐ODA has been successfully synthesized and used for the effective synthesis of Oxazolidinones and a‐hydroxy ketones under mild conditions utilizing CO2. Initially, imine‐linked 2D COF, TFP‐ODA was synthesized by simple solvothermal method followed by the embedment of copper oxide nanoparticles (NPs) into the skeleton of the as‐synthesized COF. Different characterization techniques were employed to establish the physical and chemical characteristics of both CuxOy@TFP‐ODA and TFP‐ODA COF materials. To study the catalytic efficiency of the highly porous CuxOy@TFP‐ODA, three components coupling reaction involving primary amine, propargyl alcohol and CO2 to synthesize a series of 2‐Oxazolidinone and synthesis of α‐hydroxy ketones using CO2 as a Co‐catalyst were carried out over the as‐prepared catalyst under green and sustainable conditions which illustrated excellent yields and selectivity of the corresponding products. The synthesized catalyst was proved to be completely heterogeneous and especially, the catalyst material demonstrated significant potential for reuse across several catalytic cycles.

A Fully Saturated Covalent Organic Framework.

We report the design and synthesis of the first aliphatic covalent organic framework (COF), NUS-119, and its subsequent conversion to NUS-120, marking the first fully saturated COF. NUS-119 is built by imine-linkages exhibiting high crystallinity and porosity, achieved by using a Lewis acid as a reaction modulator to circumvent compatibility issues between the Brønsted acid and the strong basic monomer. The structure was successfully solved using 3D microelectron diffraction (microED) techniques. NUS-119 and NUS-120 demonstrated remarkable catalytic performance in base-catalyzed Knoevenagel condensation reactions, exhibiting high conversion rates, excellent size selectivity, and good recyclability. This work advances the understanding of COF materials and paves the way for future research and applications.

Core-shell structures assembled from magnetic covalent organic frameworks as a Ti4+-fixed affinity substrate for the identification of phosphopeptides in colorectal cancer serum.

When it comes to the early detection of colorectal cancer (CRC), the study of protein phosphorylation is crucial. This work used magnetic covalent organic framework (COF) materials as substrates. The magCOF@PM-Ti4+ composites were obtained by constructing the three-dimensional cross-linked structures and chelating them with Ti4+ in a green and economical way, which was utilized to identify the phosphopeptides. This material possesses magnetic properties that facilitate simplified experimental manipulation, has superior sensitivity (0.2 fmol), excellent selectivity (1000:1), and good reusability (10 cycles), and achieves outstanding recovery rates (103.4 ± 1.2%). In addition, magCOF@PM-Ti4+ was utilized to identify phosphopeptides in human serum. One hundred phosphopeptides were identified from three normal control serums, whereas 98 phosphopeptides were identified from three CRC serums. The results demonstrated that magCOF@PM-Ti4+ has great potential in efficiently identifying low-abundance phosphopeptides.

Metal Imidazole-Modified Covalent Organic Frameworks as Electrocatalysts for Alkaline Oxygen Evolution Reaction.

Since the product contains no carbon-based substances and can be driven by non-carbon-based electricity, electrocatalytic water splitting is considered to be among the most effective strategies for alleviating the energy crisis and environmental pollution. This process helps lower greenhouse gas emissions while also supporting the shift toward renewable energy sources. The anodic oxygen evolution reaction (OER) involves a more complex multi-electron transfer process, which is the principal limiting factor in overall water splitting. Extensive research has demonstrated that the controlled design of effective electrocatalysts can address this limitation. In this study, a previously unreported covalent organic framework material (COF-IM) was synthesized via a post-synthetic modification strategy. Notably, COF-IM contains imidazole nitrogen metal active sites. Transition metal-coordinated COF-IM@Co can function as a highly effective electrocatalyst, exhibiting a lower overpotential (403.8 mV@10 mA cm-2) in alkaline electrolytes, thereby highlighting its potential for practical applications in energy conversion technologies. This study offers new perspectives on the design and synthesis of COFs, while also making substantial contributions to the advancement and application of OER electrocatalysts.

Convenient Aqueous‐Phase Synthesis of Covalent Organic Frameworks for Anhydrous Proton Conduction

Covalent organic frameworks (COFs) as a kind of emerging materials has been widely concerned. Developing and recovering new COF materials is of great importance for anhydrous proton conduction, most of the synthesis methods are not organic solvent phase or convenient enough, which would inevitably lead to solvent waste and increase environmental burden. Herein, a method of COF synthesis in aqueous phase is developed, which is used for nonpolluting and sustainable fabrication. Benefits from the suitable channels and stability of HCOF‐1, the composite material H3PO4@HCOF‐1 exhibit high proton conductivity (1.29 × 10−4 S cm−1) at 413 K and the crystallinity of HCOF‐1 is maintained well after measurements. This work broadens the scope of COF synthesis and promotes the development of anhydrous proton conduction.

Robust Computation and Analysis of Vibrational Spectra of Layered Framework Materials Including Host-Guest Interactions.

Layered framework materials, a rapidly advancing class of porous materials, are composed of molecular components stitched together via covalent bonds and are usually synthesized through wet-chemical methods. Computational infrared (IR) and Raman spectra are among the most important characterization tools for this material class. Besides the a priori known spectra of the molecular building blocks and the solvent, they allow for in situ monitoring of the framework formation during synthesis. Therefore, they need to capture the additional peaks from host-guest interactions and the bands from emerging bonds between the molecular building blocks, verifying the successful synthesis of the desired material. In this work, we propose a robust computational framework based on ab initio molecular dynamics (AIMD), where we compute IR and Raman spectra from the time-correlation functions of dipole moments and polarizability tensors, respectively. As a case study, we apply our methodology to a covalent organic framework (COF) material, COF-1, and present its AIMD-computed IR and Raman spectra with and without 1,4-dioxane solvent molecules in its pores. To determine robust settings, we meticulously validate our model and explore how stacking disorder and different methods for computing dipole moments and polarizabilities affect IR and Raman intensities. Using our robust computational protocol, we achieve excellent agreement with experimental data. Furthermore, we illustrate how the computed spectra can be dissected into individual contributions from the solvent molecules, the molecular building blocks of COF-1, and the bonds connecting them.

A nickel porphyrin-based covalent organic framework modified electrode for the electrochemical detection of acetaminophen.

Covalent organic frameworks (COFs) can be rationally designed with functional organic ligands to improve the electrochemical responsiveness of the electrode toward certain medicinal compounds. In this study, we synthesized a COF-Ni electrocatalyst material, which is formed by covalent coupling of electron-rich 2,3,6,7-tetrakis (4-formylphenyl) tetrakis (4-imidazolyl) (TTF-4CHO) and hole-rich 5,10,15,20-tetrakis (4-aminophenyl) porphyrin nickel(II) (TAPP-Ni). The reasonable electron transfer path design, the large specific surface area of the COF and the physical properties of ordered nanopores, as well as the Ni-N4 bond as a highly active catalytic center, allow the COF-Ni material modified electrode to exhibit excellent sensing performance for acetaminophen (ACOP). The detection limit for ACOP is as low as 47.6 nM, with a linear range of 1-1500 μM, which is better than for most of the reported sensors. With superior interference resistance and good stability performance, COF-Ni is a highly suited electrode modification material for real-world sample detection, which provided a new perspective for application of COF materials in drug analysis.

Heat-Resistant Covalent Organic Framework (COF) PVA-Hybridized Gel Electrolyte for the Preparation of Dendrite-Free Zinc-Ion Batteries.

High-performance zinc-ion batteries (ZIBs) have attracted a great deal of attention due to their high theoretical capacity and high level of safety. Herein, we propose a covalent organic framework (COF) hybrid poly(vinyl alcohol) (PVA)-based gel electrolyte, which can induce the uniform deposition of Zn2+ and achieve dendrite-free formation. By grafting sulfonic acid groups on the surface of COFs to absorb Zn2+, we can strengthen the interaction between strong ions and dipoles in the electrolyte, improve the ionic conductivity, and achieve stable Zn2+ electroplating and stripping. Due to the good thermal stability of the COF material itself, the gel electrolyte hybrid with the PVA hydrogel shows high mechanical strength and good heat resistance and is capable of stable cycling for >1000 h at 50 °C, with a capacity retention rate of ≤75%. This study provides a new approach for developing high-temperature-resistant and highly stable dendrite-free ZIBs.

Lewis Acid Regulation Strategy for Constructing D-A-A Covalent Organic Frameworks with Enhanced Photocatalytic Organic Conversion.

Owing to their excellent photoelectric properties, donor-acceptor (D-A) type photocatalytic covalent organic frameworks (COFs) have attracted significant research interest in recent years. However, the limited D-A structural units of existing COFs restrict the development of novel and efficient photocatalytic COF materials. To solve this problem, we developed a series of D-A-A-type COFs utilizing a Lewis acid regulation strategy, in which Lewis acids act as the coordination centers, and pyridine and cyano groups act as ligands. Lewis acid sites in COFs serve as electron acceptors, facilitating the separation and transfer of photogenerated electron-hole pairs. This process is crucial for photocatalysis because it significantly increases the efficiency of the catalytic reaction by reducing the recombination rate of charge carriers. The developed Lewis acid-activated D-A-A COFs efficiently catalyzed the hydroxylation of various phenylboronic acid compounds under visible light. The developed catalysts are expected to contribute to increasing the fabrication efficiency of industrially important organic materials.

Rational Design of Regenerable Amino-Functionalized Fluorescent Covalent Organic Framework for the Exclusive Detection of Mercury(II).

Goal-oriented development of novel covalent organic frameworks (COFs) to construct a sensing platform for highly toxic mercury (II, Hg2+) is of tremendous significance. Recently, numerous COFs with sulfur-based ligands were developed for Hg2+ monitoring; however, strong binding of Hg2+ by sulfur makes their regeneration very tough. Herein, we designed and developed an amino-functionalized fluorescent COF (COF-NH2) through facile postmodification for Hg2+ detection in which the π-conjugation skeleton is the signal reader and the nitrogen-based side is the highly selective Hg2+ receptor. More importantly, this nitrogen-based receptor permits the reversible binding of Hg2+. As a sensing platform, the outstanding performance of COF-NH2 for Hg2+ detection was reached with respect to high sensitivity with an ultralow detection of 15.3 nM, real-time response with rapid signal change of 10 s, and facile visualization with significant fluorescence color change. Expectedly, COF-NH2 obtained facile recycling which still shows excellent response performance toward Hg2+ after six cycles based on the reversible interaction between amino groups and Hg2+. Our work not only shows an attractive foreground of fluorescent COF for Hg2+ detection but also emphasizes the easy construction of novel COF materials via the rational introduction of metal ligands for the recognition of other metal ions.

Determination of three dechloranes in environmental water by magnetic solid-phase extraction-gas chromatography-negative chemical ionization mass spectrometry based on the covalent organic framework material

Dechloranes are additive-type chlorine flame retardants that are widely used in processing industrial products, such as electronic equipment and textiles. Dechloranes, which can enter the human body through various routes, pose significant health risks because of their toxicity, persistence, and bioaccumulation. In 2023, dechlorane plus was listed in the Stockholm Convention on Persistent Organic Pollutants. In the same year, China recognized this compound as a priority-controlled substance. Dechloranes are commonly found at trace levels in water, which is extremely harmful to the environment and human health. Therefore, the development of detection methods for dechloranes is crucial. Magnetic solid-phase extraction (MSPE) has attracted considerable attention because of its low organic solvent consumption, simplicity of adsorbent separation, and ease of operation. In general, the selectivity and efficiency of MSPE depend on the characteristics of the adsorbent. Covalent organic frameworks (COFs) have regular porosity, structural predictability and stability, high specific surface areas, and adjustable pore sizes, which are advantageous for a wide range of separation and analysis applications. In this study, Fe3O4 magnetic nanoparticles and a COF material (TpBD) were combined to prepare Fe3O4@TpBD as an adsorbent for dechloranes. Subsequently, an effective method for analyzing dechlorane in environmental water was established by coupling MSPE with gas chromatography-negative chemical ionization mass spectrometry (GC-NCI/MS). The successful synthesis of Fe3O4@TpBD was confirmed using transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry. A single-factor method was used to optimize the extraction conditions, including the Fe3O4@TpBD dosage, pH of water sample, elution solvent type and volume, extraction time, elution time, and ionic strength. The target analytes were separated on a TG-5SILMS column (30 m×0.25 mm×0.25 μm) and quantified using the external standard method in the selected-ion monitoring (SIM) mode. Under the optimal extraction conditions, the method validation results showed a linear range of 2-1000 ng/L. The limits of detection (LODs) and quantification (LOQs) were 0.18-0.27 ng/L and 0.60-0.92 ng/L, respectively, for the three analytes. The intra-day and inter-day precisions at three spiked levels were 4.2%-16.2% and 6.9%-15.7%, respectively. This method was successfully applied to the determination of dechloranes in environmental water samples (laboratory tap water, reservoir water, wastewater treatment plant effluent, and landfill leachate treatment effluent). The recoveries of the three dechloranes at different spiked levels ranged from 77.8% to 113.3% with relative standard deviations (RSDs) of 2.5%-16.3% (n=3). With the advantages of operational simplicity, high sensitivity, and good reproducibility, the proposed method is suitable for the qualitative and quantitative determination of dechloranes in environmental water.

An Ultrastable Aqueous Ammonium-Ion Battery Using a Covalent Organic Framework Anode.

Aqueous ammonium ion batteries have garnered significant research interest due to their safety and sustainability advantages. However, the development of reliable ammonium-based full batteries with consistent electrochemical performance, particularly in terms of cycling stability, remains challenging. A primary issue stems from the lack of suitable anode materials, as the relatively large NH4 + ions can cause structural damage and material dissolution during battery operation. To address this challenge, an Aza-based covalent organic framework (COF) material is introduced as an anode for aqueous ammonium ion batteries. This material exhibits superior ammonium storage capabilities compared to existing anode materials. It operates effectively within a negative potential range of 0.3 to‒1.0 V versus SCE, achieves high capacity even at elevated current densities (≈74 mAh g-1 at 10 A g-1), and demonstrates exceptional stability, retaining a capacity over 20000 cycles at 1.0 A g-1. Furthermore, by pairing this COF anode with a Prussian blue cathode, an ammonium rocking-chair full battery is developedd that maintains 89% capacity over 20000 cycles at 1.0 A g-1, surpassing all previously reported ammonium ion full batteries. This study offers insights for the design of future anodes for ammonium ion batteries and holds promise for high-energy storage solutions.

A novel dual-detection electrochemiluminescence sensor for the selective detection of Hg2⁺ and Zn2⁺: Signal suppression and activation mechanisms

In this study, we developed a novel covalent organic framework (COF) material, termed RuCOFs, specifically designed and synthesized for electrochemiluminescence (ECL) sensor applications. RuCOFs are based on the classic ECL emitter Ru(dcbpy)32+, ingeniously integrating 4,4′,4''-(1,3,5-triazine-2,4,6-triyl) triphenylamine (TAPT) with [2,2′-bipyridine]-5,5′-diamine (BPYDA), forming a structure with a high specific surface area. This configuration not only significantly enhances the stability of the ECL signal but also provides ideal N,N′-bipyridine chelating sites for efficient metal ion recognition. Utilizing Ru(dcbpy)32+-functionalized COF (RuCOFs), a novel dual-function ECL sensor was developed, achieving high sensitivity and selectivity in detecting mercury (Hg2⁺) and zinc (Zn2⁺) ions. Experimental results indicate that Hg2⁺ significantly quenches the ECL signal, while Zn2⁺ markedly enhances it, with detection limits of 4.71 nM for Hg2⁺ and 6.57 nM for Zn2⁺ across a wide linear response range from 1 μM to 1 nM. This research not only demonstrates the significant advantages of COF-based ECL sensing platforms in tracking environmental metal ions but also opens new possibilities for environmental monitoring.

A Novel Sulfonated Polyimide Composite Membrane Containing a Sulfonated Porous Material for All-Vanadium Redox Flow Batteries.

To improve the battery efficiency and cycling stability of sulfonated polyimide (SPI), a polyphosphazene with built-in -SO3H moieties (PP-SO3H), which is a porous covalent organic framework (COF) material, is facilely synthesized by the polymeric combination of hexachlorocyclotriphosphazene (HCCP) and p-diaminobenzenesulfonic acid. Due to its tunable pore size and flexible molecular design, the COF material can address the trade-off between the conductivity and the ion permeability of ion exchange membranes well, thereby improving the ion selectivity of membranes. The experimental results show that the SPI/PP-SO3H composite membrane has an excellent conductivity (up to 114.8 mS cm-1); the ion selectivity of the SPI/2% PP-SO3H membrane is 11.69 × 104 S min cm-3, which is 2.18 times higher than that of the SPI base membrane. PP-SO3H also improves the SPI membrane's mechanical strength, and the effect of PP-SO3H on SPI intermolecular interactions is analyzed by surface electrostatic potential (ESP) theoretical calculations. The Coulombic efficiency (CE) of the SPI/2% PP-SO3H membrane is 98.92%, the energy efficiency (EE) is 84.1% at a current density of 100 mA cm-2, and the self-discharge time of the SPI/2% PP-SO3H membrane is 3.5 times compared with the SPI base membrane. To measure the cycling stability of the composite membrane, the SPI/2% PP-SO3H membrane is cycled in the VRFB for more than 400 cycles, which is more stable than that of the SPI base membrane. These results show that SPI/2% PP-SO3H composite membranes are viable for VRFB applications.

Constructing covalent organic frameworks with dense thiophene S sites for effective iodine capture

Developing versatile sorption materials for radionuclide capture (e.g. iodine) is critical for nuclear energy and environmental science. Covalent organic frameworks (COFs) have recently become a new platform for developing sorption materials because of their high surface area and functionalised skeleton structure. Herein, two types of COF materials containing thiophene were designed as iodine sorbents and synthesised via a Schiff base reaction of benzo[1,2-b:3,4-b’:5,6-b’’]trithiophene-2,5,8-tricarbaldehyde, benzidine (DADP) and p-phenylenediamine (DAB): DADP-COF and DAB-COF. DAB-COF exhibits a unique granular-rod-like morphology and has a higher surface area (1775 m2/g) than DADP-COF (1140 m2/g), which is clearly beneficial for the physical adsorption of iodine. Meanwhile, the COF backbone is rich in N and S sites, which are advantageous for the chemical adsorption of iodine. These two features make the two prepared COFs ideal iodine sorption materials. DAB-COF demonstrates an excellent gaseous iodine adsorption capacity of 4.2 g/g, ranking it as one of the most effective iodine sorption materials, while DADP-COF exhibits a good adsorption capacity of over 235 mg/g for iodine in cyclohexane solutions. Density functional theory calculations prove that imine N and thiophene S serve as active sites during the iodine adsorption. DAB-COF exposes more active sites because of its higher surface area, leading to a higher iodine adsorption capacity than DADP-COF. The results of this study indicate that introducing thiophene to COFs improves sorption efficacy for sorption applications in general and particularly paves the way for developing stable and effective COF sorbents for iodine capture from various environments.