Nature Protocols
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2024
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IF 13.1
Wang Zhifang,Zhang Yushu,Liu Jinjin,Chen Yao,Cheng Peng,Zhang Zhenjie
Covalent organic frameworks (COFs) are crystalline porous polymers constructed from organic building blocks into ordered two- or three-dimensional networks through dynamic covalent bonds. Attributed to their high porosity, well-defined structure, tailored functionality and excellent chemical stability, COFs have been considered ideal sorbents for various separation applications. The synthesis of COFs mainly employs the solvothermal method, which usually requires organic solvents in sealed Pyrex tubes, resulting in unscalable powdery products and environmental pollution that seriously limits their practical applications. Herein, our protocol focuses on an emerging synthesis method for COFs based on organic flux synthesis without adding solvents. The generality of this synthesis protocol has been applied in preparing various types of COFs, including olefin-linked, imide-linked, Schiff-based COFs on both gram and kilogram scales. Furthermore, organic flux synthesis avoids the disadvantages of solvothermal synthesis and enhances the crystallization and porosity of COFs. Typically, COF synthesis takes 3–5 d to complete, and subsequent washing procedures leading to pure COFs need 1 d. The procedure for kilogram-scale production of COFs with commercially available monomers is also provided. The resulting COFs are suitable for separation applications, particularly as adsorbent materials for industrial gas separation and water treatment applications. The protocol is suited for users with prior expertise in the synthesis of inorganic materials and porous organic materials.
研究领域:
材料科学
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化学工程
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环境科学
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PubMed
高影响因子
POLYMER
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2024
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IF 4.1
Xiaoshu Wei,Xin Dong,Meiying Huang,Zhipeng Zhou,Zihao Liang,Yuyao Li,Yonghang Yang,Jiaxing Lu,Zhilv Wang,Changye Zhan,Wei Liu,Zhikun Zheng
The central feature of covalent organic frameworks (COFs) is crystallinity which is conducive to forming a uniform pore structure . However, synthesis of highly crystalline COFs based on stable covalent bonds remains formidable task. In this paper, a highly crystalline acylhydrazone COF-BD was synthesized in aqueous phase. The synthesis mechanism was proposed that the protonated hydrazide monomers dissolved in aqueous phase reacted with aldehyde monomers by deprotonation into the micellar. By investigating the effects of experimental parameters on the crystallinity of COF-BD, it was founded that under C9–COONa as surfactant , 80 °C, and 1.0 eq acetic acid as catalyst, acylhydrazone COF-BD with good crystallinity could be prepared. To prove the extensibility of this method, another acylhydrazone COF was prepared successfully.
研究领域:
材料科学
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化学
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高影响因子
Materials Today Chemistry
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2022
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IF 7.613
Tian Xia,Zhuangzhuang Wu,Ying Liang,Wenxin Wang,Yongpeng Li,Zhuyin Sui,Linlin Shan,Chaokun Li,Ruimei Fan,Qi Chen
The design and fabrication of versatile covalent organic frameworks (COFs) with multiple properties for diverse applications is highly desirable. Here, the difunctional COFs material g–C 18 N 3 –COF was prepared and modified to be applied for efficient photocatalytic degradation of Rhodamine B (RhB) and pH detection, respectively. Owing to the triazine unit which was suitable for photocatalyst construction, g–C 18 N 3 –COF was sensitive to visible light and exhibited excellent photocatalysis capability toward RhB. Specially, the photocatalytic degradation of RhB with a high concentration of 300 ppm using g–C 18 N 3 –COF reached equilibrium within 6 h. Moreover, g–C 18 N 3 –COF was further grown in-situ onto the filter paper to generate a novel composite material g–C 18 N 3 –COF@Paper with bright yellow fluorescence. g–C 18 N 3 –COF@Paper could visualize the pH detection by remarkable changes in its fluorescent intensity and color in the range of pH value from 1 to 5, on account of the protonation of the nitrogen atoms from the triazine ring in g–C 18 N 3 –COF. The triazine-based sp 2 carbon-conjugated g–C 18 N 3 –COF, respectively, used as photocatalyst and sensor in this work offers a new strategy to construct the versatile COFs material, facilitating the application of functional COFs in the environmental protection field.
研究领域:
材料科学
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环境科学
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化学工程
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高影响因子
ACS Applied Materials & Interfaces
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2023
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IF 9.5
Yanqing Cong,Xinyue Li,Shiyi Zhang,Qiuang Zheng,Yi Zhang,Shi-Wen Lv
Photocatalytic technique is regarded as the cleanest approach for producing H2O2. Herein, two kinds of novel polyimide COFs decorated with CQDs (namely, MPa-COFs/CQDs and MNd-COFs/CQDs) were constructed by using the one-pot hydrothermal method. Due to the electron donor role of CQDs, the recombination of photoinduced electrons and holes was suppressed after the combination of polyimide COFs with CQDs. Importantly, the introduction of CQDs not only boosted the absorbing ability of polyimide COFs toward visible light but also reduced the impedance and improved the charge transfer efficiency. After CQDs were embedded into polyimide COFs, the surface hydrophilicity of catalysts was significantly improved, which provided convenience for the water oxidation reaction. Benefiting from the electron donor–acceptor interaction between polyimide COFs and CQDs, a step-by-step two-electron oxygen reduction reaction over polyimide COFs was enhanced. More interestingly, the embedding of CQDs can create a direct two-electron water oxidation reaction pathway, which played an important role in photocatalytic H2O2 generation. Meanwhile, H+ generated from water oxidation can also be used for the reduction of oxygen to form H2O2. Under the synergistic effects of water oxidation and oxygen reduction, as-prepared MPa-COFs/CQDs-2 displayed excellent performance in photocatalytic H2O2 generation, and its yield was as high as 540 μmol/g within 60 min. In short, the current work shared an effective strategy to improve the performance of polyimide COFs in photocatalytic H2O2 production.
研究领域:
材料科学
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环境科学
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化学工程
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PubMed
高影响因子
Energy Storage Materials
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2020
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IF 16.28
Mi Tang,Cheng Jiang,Shiyuan Liu,Xiang Li,Yuan Chen,Yanchao Wu,Jing Ma,Chengliang Wang
Various alternatives of Li-ion batteries (LIBs) have been developed due to the scarcity of Li resources and growing demand of LIBs. However, most of these candidates are suffering the challenges of sluggish intercalations of large-sized ions (e.g. Na + , K + or anions etc.), leading to low capacity, poor cycleability and particularly performance decay at high rate. Herein, we report the precise synthesis of a novel conjugated polymer (polypyrene sulfide, PPYS) and its application in storage of anions. Furthermore, we propose a novel concept that the electropositive covalent organic frameworks (COFs) could be able to adsorb anions by electrostatic attractions and thereby facilitate the transport of anions. This novel concept for enhancing the intercalation kinetics of large-sized anions is demonstrated by using the PPYS cathodes as proof-of-concept. After addition of small amount COFs, the capacity, the rate capability and the cycleability of PPYS are improved impressively. Such strategy can be expected to be universal to other redox polymers and may be also applicable to enhance the transport of other large-sized ions in multifunctional applications. These results will also extend the application fields of COFs.
研究领域:
材料科学
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电化学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Guiliang Li,Jianrong Ye,Qile Fang,Fu Liu
Covalent organic frameworks (COFs) materials with designed skeleton structure and controlled pore size are a new class of adsorbent materials for environment remediation. Here, we synthesize two amide-based COFs materials via a polymerization reaction of acyl chloride and amino groups by mechanical ball milling at room temperature for Pb 2+ removal as adsorbents. Two types of diamine monomers are selected to construct COFs with different framework structure and functional groups contents, i.e. COF-TP from aromatic diamine and COF-TE from linear diamine. The as-prepared COFs materials display typical lamellar structure, and the amide groups on COFs skeleton are confirmed to behave as active adsorption sites for Pb 2+ capture via multi-coordination. COF-TE exhibits superior Pb 2+ adsorption capacity to COF-TP, because that less aromatic skeleton and weak π-π stacking of COF-TE facilitate higher internal diffusion of Pb 2+ adsorption. Meanwhile, the higher amide group content on COF-TE leads to its higher saturated adsorption capacity of 185.7 mg/g than COF-TP of 140.0 mg/g. Finally, great recycling stability of Pb 2+ adsorption allows the amide-based COFs materials to be promising adsorbents for heavy metal Pb 2+ removal or recovery.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
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2022
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IF 5.876
Yanbo Zhang,Quan Wang,Yongqiang Li,Ronggui Hu
Covalent organic frameworks (COFs) are promising in the detection and removal of toxic heavy metal ions from water. However, achieving detection and removal functions requires systematic control of stability, porosity, pore environment, and luminescence properties, which remains a challenge for most COFs materials. Herein, we develop a bithiophene-based stable COF, TAPA-BTDC, with dual functions of simultaneous detection and removal of silver ions from aqueous solution through elaborate structural design and control of the pore environment. The obtained TAPA-BTDC has good thermal stability and chemical stability, possesses high crystallinity and moderate specific surface area (396.83 m 2 /g), and contains dense bithiophene-S chelating sites on the pore walls. These characteristics work together to give TAPA-BTDC the dual function of selective detection and effective removal of silver ions from aqueous solution. This dual function can be attributed to the π-complexation between bithiophene-S chelating sites and silver ions, as verified by X-ray photoelectron spectroscopy. The charge transfer between bithiophene-S and silver ions alters the weak fluorescence emission caused by the π−π layered structure, enabling TAPA-BTDC to selectively detect silver ions through fluorescence enhancement, and even trace amounts of Ag + (2.4 × 10 −4 mmol/L) can cause observable fluorescence emission. Meanwhile, these bithiophene-S scattered across the pore wall also provide a large number of accessible chelating sites for TAPA-BTDC, enabling it to effectively remove Ag + with a maximum adsorption capacity up to 398.61 mg/g, and TAPA-BTDC can be easily regenerated five times without loss of performance. The results of this study reveal the exceptional potential of COFs with reasonably tailor-made structure in dealing with heavy metal ion contamination.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2018
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IF 2.21
Xiaowei Mu,Ying Pan,Chao Ma,Jing Zhan,Lei Song
Co 3 O 4 /COFs nanohybrids are prepared through ball milling of covalent organic frameworks (COFs) nanosheets synthesized from condensation reaction between melamine and o -Phthalaldehyde and then modified with Co 3 O 4 particles first. Polypropylene (PP) composite with different weight loading of Co 3 O 4 /COFs nanohybrids has also been prepared. Successful preparation of Co 3 O 4 /COFs nanohybrids has been proved by the typical reflections of Co 3 O 4 including (111), (220) and (222) in XRD pattern, O–Co–O (663 cm −1 ) and Co–O (569 cm −1 ) stretching vibrations in FTIR spectrum and Co 3 O 4 particles with a diameter from 20 to 50 nm on COFs nanosheets in TEM image. Flame retardant , smoke and carbon monoxide (CO) suppression and thermal properties of PP have been enhanced obviously. The temperature at initial degradation and the maximum weight loss rate of PP loaded with 3.2 wt% Co 3 O 4 /COFs nanohybrids increase 21 °C and 49 °C under air compared with that of untreated PP, respectively. The total smoke release (TSR) of PP loaded with 0.2 wt% Co 3 O 4 /COFs nanohybrids decreases by 22% compared with that of PP 0. The pyrolysis products of PP composite including hydrocarbons, carbon dioxide and CO also decrease. The feasible mechanism for inhibiting fire hazard of PP composite has also been proved. This work broadens application of COFs derivative into polymer matrix .
研究领域:
材料科学
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高分子化学
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高影响因子
Materials
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2025
·Vol. 18
·期 8
·1874
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IF 3.2
Chao Wu,Haoyan Zhang,Xuan Zheng,Jing Ding,Yuanyuan Li,Feiyong Chen,Zhengfeng Zhao
The urgency of reducing pollution and developing clean energy storage requires efficient photocatalytic hydrogen evolution (PHE) tactics. To improve solar conversion efficiency, it is highly imperative to accelerate the photocarriers separation and transport through materials design. A stable hydrogen evolution photocatalyst based on TpPa-COFs (triformylphloroglucinol phenylenediamine covalent organic frameworks) was developed by a molecular-level design strategy. The study successfully introduced a molecular-scale Ir active site onto the surface of TpPa-COFs via coordination bonds. It verified the structural integrity of TpPa-COFs and the existence of Ir through the basic structural characterizations, such as Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). After the Ir-based coordination compound joining, the absorption edge of TpPa-COF-M1 and TpPa-COF-M2 was extended to 750 nm. The TpPa-COF + M1 exhibited the highest photocatalytic H2evolution rate of 662 µmol/h (10 mg catalyst) under visible-light (λ ≥ 420 nm) irradiation. The apparent quantum yield (AQY) of TpPa-COF-M1 is calculated to be 1.9%, 3.8%, 4.8%, 2.8%, 1.8%, and 0.3% at monochromatic wavelengths of 420, 450, 470, 500, 550, and 600 nm, respectively. Our findings confirm that the molecular-level design of photocatalysts can effectively boost performance and reduce cost in photocatalytic reactions and provide an important strategy for designing efficient photocatalysts.
研究领域:
材料科学
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能源化学
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光催化
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DOI
PubMed
高影响因子
MICROCHEMICAL JOURNAL
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2025
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IF 5.1
Xiuzhen Li,Yuanting Ni,Chenxi Liu,Shaohua Xu,Wei Shu,Hong Liang,Ming Chen
Background Homocysteine (Hcy) has been recognized as an independent risk factor for the development of cardiovascular disease. Many electrochemical detection methods have been developed for analyzing Hcy, however, the specificity of these methods is based on the interaction between the sulfhydryl groups in Hcy and the metallic materials, and thus the specificity of such detection is not satisfactory. Results In this study, an electrochemical sensor based on COFs and Pd@CuO was developed for the specific detection of Hcy. Firstly, COFs material was used as an immobilized carrier for cystathionine β-synthase (CBS), and the immobilized CBS as a recognition unit was able to catalyze the production of H 2 S from the substrates (Hcy and Cys) in a specific manner. Secondly, the Pd@CuO composite material has excellent conductivity and can catalyze H 2 S as a source of electrochemical signal generation. The electrochemical sensor constructed based on the above principles has a good electrochemical response to Hcy within the range of 5 μM to 100 μM, and the limit of detection can reach 0.11 μM (S/N = 3). In addition, the constructed sensor has good reproducibility, stability and specificity, and has good recoveries in the detection of real plasma samples, which provides a potential application for the diagnosis of homocysteinemia. Significance and Novelty The electrochemical sensor significantly increases the specificity of detection by utilizing immobilized Hcy specific catalytic enzymes CBS. In addition, Pd modified CuO@COFs electrode greatly increases the conductivity of the electrode, thereby increasing the sensitivity of detection. These characteristics make the electrochemical sensor have good application prospects for detecting the Hcy in clinic in the future.
研究领域:
生物医学工程
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分析化学
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临床诊断
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DOI
高影响因子
DESALINATION
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2024
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IF 8.3
Lin Yu,Aida Aibulatova,Zhen-Liang Xu,Li Li,Changqing Hao,Rui Jia,Yin-Xin Fang,Yan Zheng,Yong-Jian Tang
Covalent Organic Framework Materials (COFs) nanofiltration (NF) membranes have extensive applications in the field of separation. In this work, high performance TpPa COFs NF membranes were prepared with catalyst pre-diffused strategy. The catalyst pre-diffused method can let catalyst attached to the membrane surface, which can promote the formation of intermediates first, and then form a complete COFs separator layer in 30 min. The optimized membrane possesses an excellent performance of CR permeability of 97.57 L⋅m −2 ⋅h −1 ⋅bar −1 with a rejection of 99.25 % for CR. The dye/salt separation selectivity α was up to 480.16 (EB-T/NaCl). This markedly decreases the reaction duration for membrane production and enhances preparation efficiency. Consequently, the catalyst pre-diffusion strategy offers an innovative approach for the fabrication of COFs nanofiltration membranes.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
MICROCHEMICAL JOURNAL
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2026
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IF 5.2
Minghui Wang,Qiaolin Guo,Zhenyong Hu,Yue He,Lai Zhang,Cuifei Chen
An ultrasensitive biosensor has been developed for miR-375 detection. • HRP is embedded into COFs to form stable HRP@COFs co-precipitated nanospheres. • The HRP@COFs preserved enzymatic activity and enhanced catalytic efficiency. • The biosensor has been successfully validated using clinical samples. The dysregulated expression of microRNA (miRNA) in various cancers has attracted considerable attention owing to their crucial roles in tumor initiation and progression. Among them, miR-375 has been recognized as a prospective biomarker for early malignancy detection and therapeutic monitoring. In this study, a highly sensitive electrochemical biosensor has been developed based on horseradish peroxidase (HRP)-embedded covalent organic framework (HRP@COFs) co-precipitated nanospheres for the detection of miR-375. The HRP@COFs nanocomposite effectively preserves the enzymatic activity of HRP while providing the structural stability and high loading capacity of COFs, thereby enhancing catalytic efficiency and signal amplification. In the presence of target miR-375, the azide-modified H1 hairpin probes on the HRP@COFs surface are activated, leading to the formation of a rigid H1-H2 duplex structure through competitive hybridization with H2 hairpins. The resulting H2-H1-HRP@COFs complexes are subsequently anchored onto the electrode surface via click chemistry. Upon the addition of H 2 O 2 , HRP catalyzes aniline polymerization and deposition, resulting in a significant electrochemical response. This biosensor achieves ultrasensitive detection of miR-375 with a detection limit as low as 230 aM. It has been successfully validated using clinical samples, demonstrating great potential for reliable breast cancer diagnosis. This work highlights the synergistic advantages of integrating HRP with COFs, providing a robust and efficient platform for microRNA detection and expanding the applications of COFs-based materials in biosensing and clinical diagnostics. Download: Download high-res image (151KB) Download: Download full-size image
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高影响因子
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