Cu2+ coordination-induced in situ photo-to-heat on catalytic sites to hydrolyze ß-lactam antibiotics pollutants in waters.

For degradation of ß-lactam antibiotics pollution in waters, the strained ß-lactam ring is the most toxic and resistant moiety to biodegrade and redox-chemically treat among their functional groups. Hydrolytically opening ß-lactam ring with Lewis acid catalysts has long been recognized as a shortcut, but at room temperature, such hydrolysis is too slow to be deployed. Here, we found when Cu2+ was immobilized on imine-linked COF (covalent organic framework) (Cu2+/Py-Bpy-COF, Cu2+ load is 1.43 wt%), as-prepared composite can utilize the light irradiation (wavelength range simulated sunlight) to in situ heat anchored Cu2+ Lewis acid sites through an excellent photothermal conversion to open the ß-lactam ring followed by a desired full-decarboxylation of hydrolysates. Under 1 W/cm2 simulated sunlight, Cu2+/Py-Bpy-COF powders placed in a microfiltration membrane rapidly cause a temperature rising even to ~211.7 °C in 1 min. It can effectively hydrolyze common ß-lactam antibiotics in waters and even antibiotics concentration is as high as 1 mM and it takes less than 10 min. Such photo-heating hydrolysis rate is ~24 times as high as under dark and ~2 times as high as Cu2+ homogenous catalysis. Our strategy significantly decreases the interference from generally coexisting common organics in waters and potential toxicity concerns of residual carboxyl groups in hydrolysates and opens up an accessible way for the settlement of ß-lactam antibiotics pollutants by the only energy source available, the sunlight.

Linkage-Mixed Covalent Organic Frameworks Synthesized by a Liquid-Solid Two-Phase Strategy for Photoenhanced Uranium Extraction.

Synthesizing COFs with hybrid linkage coupling with both reversible and irreversible natures remains a challenging issue. Herein, we report the synthesis of two rare COFs constructed by both reversible and irreversible linkages through a liquid-solid two-phase strategy. A systematic study reveals a one-pot, two-step reaction mechanism for the two COFs, the first step being a reversible Schiff base reaction and the second step being an irreversible Knoevenagel reaction. Interestingly, this hybrid linkage COF is found to show an outstanding photoenhanced uranium extraction performance. The results not only provide a general and green approach to develop the linkage chemistry of COFs but also enrich the synthesis toolboxes and application of COFs.

Tunable Band Engineering Management on Perovskite MAPbBr3 /COFs Nano-Heterostructures for Efficient S-S Coupling Reactions.

Efficient artificial photosynthesis of disulfide bonds holds promises to facilitate reverse decoding of genetic codes and deciphering the secrets of protein multilevel folding, as well as the development of life science and advanced functional materials. However, the incumbent synthesis strategies encounter separation challenges arising from leaving groups in the ─S─S─ coupling reaction. In this study, according to the reaction mechanism of free-radical-triggered ─S─S─ coupling, light-driven heterojunction functional photocatalysts are tailored and constructed, enabling them to efficiently generate free radicals and trigger the coupling reaction. Specifically, perovskites and covalent organic frameworks (COFs) are screened out as target materials due to their superior light-harvesting and photoelectronic properties, as well as flexible and tunable band structure. The in situ assembled Z-scheme heterojunction MAPB-M-COF (MAPbBr3 = MAPB, MA+ = CH3 NH2 + ) demonstrates a perfect trade-off between quantum efficiency and redox chemical potential via band engineering management. The MAPB-M-COF achieves a 100% ─S─S─ coupling yield with a record photoquantum efficiency of 11.50% and outstanding cycling stability, rivaling all the incumbent similar reaction systems. It highlights the effectiveness and superiority of application-oriented band engineering management in designing efficient multifunctional photocatalysts. This study demonstrates a concept-to-proof research methodology for the development of various integrated heterojunction semiconductors for light-driven chemical reaction and energy conversion.

Imaging the Iodine Sorption-Induced Synchronous Skeleton-Pore Interactions of Single Covalent Organic Framework Particles.

Covalent organic frameworks (COFs) are promising iodine adsorbents. For improved performances, it is critical and essential to fundamentally understand the underlying mechanism. Here, using the operando dark-field optical microscopy (DFM) imaging technique, the observation of an extraordinary structure shrinkage of 2D triphenylbenzene (TPB)-dimethoxyterephthaldehyde (DMTP)-COF upon the adsorption of I2 vapor at the single-particle resolution is reported. Combining single-particle DFM imaging with other experimental and theoretical methods, it is revealed that the shrinkage mechanism of the TPB-DMTP-COF is attributed to the I2 sorption-induced synchronous skeleton-pore interactions. The redox reaction of I2 and TPB-DMTP-COF yields some cationic skeletons and I3 - species, which triggers the multi-directional halogen-bonding interactions of I2 and I3 - as well as strong cation-π interactions between neutral and cationic skeletons, accompanying the synchronous in-plane skeleton shrinking in the xy plane and compact out-of-plane layer packing in the z-direction. This understanding of the synchronous action between the skeleton and pore breaks the perspective on the structure robustness of 2D COFs with excellent stability during the I2 uptake, which offers pivotal guidance for the rational design and creation of advanced microporous adsorbents.

Construction of Multifunctional Covalent Organic Frameworks for Photocatalysis.

Covalent organic frameworks (COFs) have recently drawn intense attention due to their potential applications in photocatalysis. Herein, we report a multifunctional COF which consists of triphenylamine (TPA) and 2,2'-bipyridine (2, 2'-bipy) entities. The obtained TAPA-BPy-COF is a heterogeneous photocatalyst and can efficiently catalyze the oxidative coupling of thiols to disulfides. In addition, TAPA-BPy-COF can be further metalated by Pd(II) via 2,2'-bipy-metal coordination. The generated Pd@TAPA-BPy-COF can highly promote photocatalytic synthesis of 3-cyanopyridines via cascade addition/cyclization of arylboronic acids with γ-ketodinitriles in heterogeneous way. This work has demonstrated the way for the rational design and preparation of more efficient photoactive COFs for photocatalysis.

Synthetic Strategies to Extended Aromatic Covalent Organic Frameworks.

π-Conjugated materials are highly attractive owing to their unique optical and electronic properties. Covalent organic frameworks (COFs) offer a great opportunity for precise arrangement of building units in a π-conjugated crystalline matrix and tuning of the properties through choice of functionalities or post-synthetic modification. With this review, we aim at summarizing both the most representative as well as emerging strategies for the synthesis of π-conjugated COFs. We give examples of direct synthesis using large, π-extended building blocks. COFs featuring fully conjugated linkages such as vinylene, pyrazine, and azole are discussed. Then, post-synthetic modification methods that result in the extension of the COF π-system are reviewed. Throughout, mechanistic insights are presented when available. In the context of their utilization as film devices, we conduct a concise survey of the prominent COF layer deposition techniques reported and their aptness for the deposition of fused aromatic systems.

Modular Construction of Vinylene-Linked Covalent Organic Frameworks with Tunable Emission for Tumor Visualization.

Covalent organic frameworks (COFs) with ordered π structures are very promising in porous light-emitting materials. However, most of these COFs are either poor in luminescence or lack of water-stability. Herein, a series of isostructural D-A vinylene-linked COFs were constructed based a new D2h symmetric linker 1,4-bis(4,6-dimethyl-1,3,5-triazin-2-yl)benzene (TMTA) with high crystallinity, comparative high surface area and excellent chemical/thermal stability. Impressively, their adsorption and luminescence wavelength vary with respect to the density of π-systems in the electron-donating group, which constitute the foundation for molecular engineering the luminescent properties of vinylene-linked COFs. The DFT calculations further established the relationship between the luminescence properties and the donor electronic structure. Moreover, one of representative COF named FZU-203 showed inspiring applications in bioimaging, which may further provide strategic guidance for the use of vinylene-linked COFs as fluorescent nanoprobes in non-invasive medical diagnosis and visualization therapy of tumors.

Progress and Perspectives on Promising Covalent-Organic Frameworks (COFs) Materials for Energy Storage Capacity.

In recent years, a new class of highly crystalline advanced permeable materials covalent-organic frameworks (COFs) have garnered a great deal of attention thanks to their remarkable properties, such as their large surface area, highly ordered pores and channels, and controllable crystalline structures. The lower physical stability and electrical conductivity, however, prevent them from being widely used in applications like photocatalytic activities and innovative energy storage and conversion devices. For this reason, many studies have focused on finding ways to improve upon these interesting materials while also minimizing their drawbacks. This review article begins with a brief introduction to the history and major milestones of COFs development before moving on to a comprehensive exploration of the various synthesis methods and recent successes and signposts of their potential applications in carbon dioxide (CO2 ) sequestration, supercapacitors (SCs), lithium-ion batteries (LIBs), and hydrogen production (H2 -energy). In conclusion, the difficulties and potential of future developing with highly efficient COFs ideas for photocatalytic as well as electrochemical energy storage applications are highlighted.

Constructing green superhydrophilic and superoleophobic COFs-MOFs hybrid-based membrane for efficiently emulsion separation and synchronous removal of microplastics, dyes, and pesticides.

Oil spills and micropollutants have become thorny environmental issues, posing serious threat to ecosystem and human health. To settle such dilemma, this study successfully constructed a robust and environmentally-friendly MOFs-COFs hybrid-based membrane (FS-50/COF(MATPA)-MOF(Zr)/PDA@PVDF) for the first time through solution synthesis and solvothermal method, combined with surface modification of FS-50 molecule. Importantly, we employed a simple two-step strategy to obtain the high-aspect-ratio MOFs fibers: (1) solvent regulation to generate smaller needle-like whiskers during the in-situ growth of MOFs on COFs; (2) high pressure induced directional crystallization in filtration process. The introduction of polydopamine (PDA) greatly improved the adhesion between coating and PVDF membrane. The in-situ growth of high length-diameter ratio MOFs fibers on blocky COFs greatly enhanced the specific surface area of MOFs-COFs hybrid, thus provided sufficient absorption sites. The functional groups of FS-50 endowed the hybrid membrane with superhydrophilicity and superoleophobicity, which facilitated to selectively penetrate water molecules and repel non-polar pollutants. The separation efficiency and decontamination mechanism of hybrid membrane to the simulated oily wastewater (containing various MPs, dyes, and pesticides) were investigated through experiments and theoretical calculations. The hybrid membrane could selectively and synchronously adsorb various dyes (20 mg/L-120 mg/L, almost 100% removal) and pesticides (10 mg/L for DIF and TET, adsorption rates 93.2% and 90.9%, respectively) from oil-water emulsion (50 mL). The large-scale coated sponge (6 cm × 4.5 cm × 3 cm) could quickly achieve separation of oil-water mixture (almost 100%) with a water permeability of more than 162 L m-2·h-1·bar-1, and simultaneously remove various MPs (PP-2000, PP-100, PE-2000, PS-100, 0.2 g/300 mL for each), Sudan Ⅲ (C0 = 200 mg/L), and DIF (C0 = 10 mg/L) from a simulant oily wastewater (300 mL), with the removal rates of almost 100% for MPs, 99.7% for Sudan Ⅲ, and 95.8% for DIF. Furthermore, we elucidated the removal mechanism of pesticide and dyes through simulating the theoretical adsorption energy and potential adsorption sites. The hybrid membrane not only provides a promising candidate for the removal of multiple pollutants from oil-water emulsion, but also opens a new strategy for achieving efficient and clean aquatic environment restoration.

Analysis of extracellular and intracellular antibiotic resistance genes in commercial organic fertilizers reveals a non-negligible risk posed by extracellular genes.

Livestock manure is known to be a significant reservoir of antibiotic resistance genes (ARGs), posing a major threat to human health and animal safety. ARGs are found in both intracellular and extracellular DNA fractions. However, there has been no comprehensive analysis of these fractions in commercial organic fertilizers (COFs). The present study conducted a systematic survey of the profiles of intracellular ARGs (iARGs) and extracellular ARGs (eARGs) and their contributing factor in COFs in Northern China. Results showed that the ARG diversity in COFs (i.e., 57 iARGs and 53 eARGs) was significantly lower than that in cow dung (i.e., 68 iARGs and 69 eARGs). The total abundance of iARGs and eARGs decreased by 85.7% and 75.8%, respectively, after compost processing, and there were no significant differences between iARGs and eARGs in COFs (P > 0.05). Notably, the relative abundance of Campilobacterota decreased significantly (99.1-100.0%) after composting, while that of Actinobacteriota and Firmicutes increased by 21.1% and 29.7%, respectively, becoming the dominant bacteria in COFs. Co-occurrence analysis showed that microorganisms and mobile genetic elements (MGEs) were more closely related to eARGs than iARGs in COFs. And structural equation models (SEMs) further verified that microbial community was an essential factor regulating iARGs and eARGs variation in COFs, with a direct influence (λ = 0.74 and 0.62, P < 0.01), following by similar effects of MGEs (λ = 0.59 and 0.43, P < 0.05). These findings indicate the need to separate eARGs and iARGs when assessing the risk of dissemination and during removal management in the environment.

Covalent Organic Frameworks Based Electrocatalysts for Two-Electron Oxygen Reduction Reaction: Design Principles, Recent Advances, and Perspective.

Hydrogen peroxide (H2O2) is an environmentally friendly oxidant with a wide range of applications, and the two-electron pathway (2e-) of the oxygen reduction reaction (ORR) for H2O2 production has attracted much attention due to its eco-friendly nature and operational simplicity in contrast to the conventional anthraquinone process. The challenge is to design electrocatalysts with high activity and selectivity and to understand their structure-activity relationship and catalytic mechanism in the ORR process. Covalent organic frameworks (COFs) provide an efficient template for the construction of highly efficient electrocatalysts due to their designable structure, excellent stability, and controllable porosity. This review firstly outlines the design principles of COFs, including the selection of metallic and nonmetallic active sites, the modulation of the electronic structure of the active sites, and the dimensionality modulation of the COFs, to provide guidance for improving the production performance of H2O2. Subsequently, representative results are summarized in terms of both metallic and metal-free sites to follow the latest progress. Moreover, the challenges and perspectives of 2e- ORR electrocatalysts based on COFs are discussed.

Covalent Bonding of MXene/COF Heterojunction for Ultralong Cycling Li-Ion Battery Electrodes.

Covalent organic frameworks (COFs) have emerged as promising renewable electrode materials for LIBs and gained significant attention, but their capacity has been limited by the densely packed 2D layer structures, low active site availability, and poor electronic conductivity. Combining COFs with high-conductivity MXenes is an effective strategy to enhance their electrochemical performance. Nevertheless, simply gluing them without conformal growth and covalent linkage restricts the number of redox-active sites and the structural stability of the composite. Therefore, in this study, a covalently assembled 3D COF on Ti3C2 MXenes (Ti3C2@COF) is synthesized and serves as an ultralong cycling electrode material for LIBs. Due to the covalent bonding between the COF and Ti3C2, the Ti3C2@COF composite exhibits excellent stability, good conductivity, and a unique 3D cavity structure that enables stable Li+ storage and rapid ion transport. As a result, the Ti3C2-supported 3D COF nanosheets deliver a high specific capacity of 490 mAh g-1 at 0.1 A g-1, along with an ultralong cyclability of 10,000 cycles at 1 A g-1. This work may inspire a wide range of 3D COF designs for high-performance electrode materials.

Extending the π-Conjugation of A Donor-Acceptor Covalent Organic Framework for High-Rate and High-Capacity Lithium-Ion Batteries.

Realizing high-rate and high-capacity features of Lihium-organic batteries is essential for their practical use but remains a big challenge, which is due to the instrinsic poor conductivity, limited redox kinetics and low utility of organic electrode mateials. This work presents a well-designed donor-acceptor Covalent Organic Framework (COFs) with extended conjugation, mesoscale porosity, and dual redox-active centers to promote fast charge transfer and multi-electron processes. As anticipated, the prepared cathode with benzo [1,2-b:3,4-b':5,6-b''] trithiophene (BTT) as p-type and pyrene-4,5,9,10-tetraone (PTO) as n-type material (BTT-PTO-COF) delivers impressive specific capacity (218 mAh g-1 and 275 mAh g-1 at 0.2 A g-1 in ether-based and carbonate-based electrolyte respectively) and outstanding rate capability (79 mAh g-1 at 50 A g-1 in ether-based electrolyte and 124 mAh g-1 at 10 A g-1 in carbonate-based electrolyte). Moreover, the potential of BTT-PTO-COF electrode for prototype batteries has been demonstrated by full cells of dual-ion batteries, which attain comparable electrochemical performances to the half cells. Moreover, mechanism studies combining ex-situ characterization and theoratical calculations reveal the efficient dual-ion storage process and facile charge transfer of BTT-PTO-COF. This work not only expands the diversity of redox-active COFs but also provide concept of structure design for high-rate and high-capacity organic electrodes.

Multipolar Conjugated Polymer Framework Derived Ionic Sieves via Electronic Modulation for Long-Life All-Solid-State Li Batteries.

Here, we build a tunable multipolar conjugated polymer framework platform via pore wall chemistry to probe the role of electronic structure engineering in improving the Li+ conduction by theoretical studies. Guided by theoretical prediction, we develop a new cyano-vinylene-linked multipolar polymer framework namely CNF-COF, which can act as efficient ion sieves to modify solid polymer electrolytes to simultaneously tune Li+ migration and stable Li anodes for long-lifespan all-solid-state (ASS) Li metal batteries at high rate. The dual-decoration of cyano and fluorine groups in CNF-COF favorably regulates electronic structure via multipolar donor-acceptor electronic effects to afford proper energy band structure and abundant electron-rich sites for enhanced oxidative stability, facilitated ion-pair dissociation and suppressed anion movements. Thus, the CNF-COF incorporation into poly (ethylene oxide) (PEO) electrolytes not only renders fast selective Li+ transport but also facilitates the Li dendrite suppression. Specifically, the constructed PEO composite electrolyte with an ultra-low CNF-COF content of only 0.5 wt % is endowed with a wide electrochemical window, a high ionic conductivity of 0.634 mS cm-1 at 60 °C and a large Li+ transference number of 0.81-remarkably outperforming CNF-COF-free counterparts (0.183 mS cm-1 and 0.22). As such, the Li symmetric cell delivers stable Li plating/stripping over 1400 h at 0.1 mA cm-2. Impressively, by coupling with LiFePO4 (LFP) cathodes, the assembled ASS Li battery under 60 °C allows for stable cycling over 2000 cycles at 1 C and over 1000 cycles even at 2 C with a large capacity retention of ~75 %, surpassing most reported ASS Li batteries using PEO-based electrolytes.

Post-synthetic Rhodium (III) Complexes in Covalent Organic Frameworks for Photothermal Heterogeneous C-H Activation.

Although photocatalytic C-H activation has been realized by using heterogeneous catalysts, most of them require high-temperature conditions to provide the energy required for C-H bond breakage. The catalysts with photothermal conversion properties can catalyze this reaction efficiently at room temperature, but so far, these catalysts have been rarely developed. Here, we construct bifunctional catalysts Rh-COF-316 and -318 to combine photosensitive covalent organic frameworks (COFs) and transition-metal catalytic moiety using a post-synthetic approach. The Rh-COF enable the heterogeneous C-H activation reaction by photothermal conversion for the first time, and exhibit excellent yields (up to 98 %) and broad scope of substrates in [4+2] annulation at room temperature, while maintaining the high stability and recyclability. Significantly, this work is the highest yield reported so far in porous materials catalyzing C(sp2)-C(sp2) formation at room temperature. The excellent performances can be attributed to the COF-316, which enhances the photothermal effect (ΔT=50.9 °C), thus accelerating C-H bond activation and the exchange of catalyst with substrates.

The Transfer Dehydrogenation Method Enables a Family of High Crystalline Benzimidazole-linked Cu (II)-phthalocyanine-based Covalent Organic Frameworks Films.

Heterocycle-linked phthalocyanine-based COFs with close-packed π-π conjugated structures are a kind of material with intrinsic electrical conductivity, and they are considered to be candidates for photoelectrical devices. Previous studies have revealed their applications for energy storage, gas sensors, and field-effect transistors. However, their potential application in photodetector is still not fully studied. The main difficulty is preparing high-quality films. In our study, we found that our newly designed benzimidazole-linked Cu (II)-phthalocyanine-based COFs (BICuPc-COFs) film can hardly formed with a regular aerobic oxidation method. Therefore, we developed a transfer dehydrogenation method with N-benzylideneaniline (BA) as a mild reagent. With this in hand, we successfully prepared a family of high crystalline BICuPc-COFs powders and films. Furthermore, both of these new BICuPc-COFs films showed high electrical conductivity (0.022-0.218 S/m), higher than most of the reported COFs materials. Due to the broad absorption and high conductivity of BICuPc-COFs, synaptic devices with small source-drain voltage (VDS=1 V) were fabricated with response light from visible to near-infrared. Based on these findings, we expect this study will provide a new perspective for the application of conducting heterocycle-linked COFs in synaptic devices.

Fully sp2 Carbon-conjugated Covalent Organic Frameworks with Multiple Active Sites for Advanced Lithium-ion Battery Cathodes.

Covalent organic frameworks (COFs) hold great promise for rechargeable batteries. However, the synthesis of COFs with abundant active sites, excellent stability, and increased conductivity remains a challenge. Here, chemically stable fully sp2 carbon-conjugated COFs (sp2c-COFs) with multiple active sites are designed by the polymerization of benzo[1,2-b:3,4-b':5,6-b'']trithiophene-2,5,8-tricarbaldehyde) (BTT) and s-indacene-1,3,5,7(2H,6H)-tetrone (ICTO) (denoted as BTT-ICTO). The morphology and structure of the COF are precisely regulated from "butterfly-shaped" to "cable-like" through an in-situ controllable growth strategy, significantly promoting the exposure and utilization of active sites. When the unique "cable-like" BTT-ICTO@CNT is employed as lithium-ion batteries (LIBs) cathode, it exhibits exceptional capacity (396 mAh g-1 at 0.1 A g-1 with 97.9% active sites utilization rate), superb rate capacity (227 mAh g-1 at 5.0 A g-1), and excellent cycling performance (184 mAh g-1 over 8000 cycles at 2.0 A g-1 with 0.00365% decay rate per cycle). The lithium storage mechanism of BTT-ICTO is exhaustively revealed by in-situ Fourier transform infrared, in-situ Raman, and density functional theory calculations. This work provides in-depth insights into fully sp2c-COFs with multiple active sites for high-performance LIBs.

Continuous Covalent Organic Frameworks Membranes: From Preparation Strategies to Applications.

Covalent organic frameworks (COFs) are porous crystalline polymeric materials formed by the covalent bonding of organic units. The abundant organic units library gives the COFs species diversity, easily tuned pore channels, and pore sizes. In addition, the periodic arrangement of organic units endows COFs regular and highly connected pore channels, which has led to the rapid development of COFs in membrane separations. Continuous defect-free and high crystallinity of COF membranes is the key to their application in separations, which is the most important issue to be addressed in the research. This review article describes the linkage types of covalent bonds, synthesis methods, and pore size regulation strategies of COFs materials. Further, the preparation strategies of continuous COFs membranes are highlighted, including layer-by-layer (LBL) stacking, in situ growth, interfacial polymerization (IP), and solvent casting. The applications in separation fields of continuous COFs membranes are also discussed, including gas separation, water treatment, organic solvent nanofiltration, ion conduction, and energy battery membranes. Finally, the research results are summarized and the future prospect for the development of COFs membranes are outlined. More attention may be paid to the large-scale preparation of COFs membranes and the development of conductive COFs membranes in future research.

Recent Progress of Covalent Organic Frameworks-Based Materials in Photocatalytic Applications: A Review.

Covalent organic frameworks (COFs) are one type of porous organic materials linked by covalent bonds. COFs materials exhibit many outstanding characteristics such as high porosity, high chemical and thermal stability, large specific surface area, efficient electron transfer efficiency, and the ability for predesigned structures. These exceptional advantages enable COFs materials to exhibit remarkable performance in photocatalysis. Additionally, the activity of COFs materials as photocatalysts can be significantly upgraded by ion doping and the formation of heterojunctions. This paper summarizes the latest research progress on COF-based materials applied in photocatalytic systems. Initially, typical structures and preparation methods of COFs are analyzed and compared. Moreover, the essential principles of photocatalytic reactions over COFs-based materials and the latest research developments in photocatalytic hydrogen production, CO2 reduction, pollutants elimination, organic transformation, and overall water splitting are indicated. At last, the outlook and challenges of COF-based materials in photocatalysis are discussed. This review is intended to permit instructive guidance for the efficient use of photocatalysis based on COFs in the future.

Room-Temperature Synthesis of a COFs Membrane Via LBL Self-Assembly Strategy for Energy Harvesting.

The covalent organic frameworks (COFs) membrane with ordered and confined one-dimensional channel has been considered as a promising material to harvest the salinity gradient energy from the seawater and river water. However, the application of the COFs in the field of energy conversion still faces the challenges in membrane preparation. Herein, energy harvesting is achieved by taking advantage of a COFs membrane where TpDB-HPAN is synthesized via layer-by-layer self-assembly strategy at room temperature. The carboxy-rich TpDB COFs can be expediently assembled onto the substrate with an environmental-friendly method. The increased open-circuit voltage (Voc ) endows TpDB-HPAN membrane with a remarkable energy harvesting performance. More importantly, the application perspective is also illuminated by the cascade system. With the advantages of green synthesis, the TpDB-HPAN membrane can be considered as a low-cost and promising candidate for energy conversion.