2D Covalent Organic Frameworks 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.

Dimensionality and Molecular Packing Control of Covalent Organic Frameworks through Pendant Group Design.

Tuning the dimensions and molecular packing geometry of crystalline organic frameworks and polymers represents an important challenge for reticular chemistry. Here we show that for extended structures made of 1,3,6,8-tetrakis(4-aminophenyl)pyrene (PyTTA) linked with methoxy group functionalized terephthalaldehyde aldehydes, simple substituents on the aldehyde linker can have profound structure directing effects due to noncovalent interactions. Specifically, reacting 2,3-dimethoxyterephthalaldehyde with PyTTA gives a 2D covalent organic framework with unique AA-inclined-AA stacking and bilayer pyrene motifs, whereas reacting 2,5-dimethoxyterephthalaldehyde with PyTTA gives a 1D crystalline polymer with AB stacking and isolated pyrene motifs. Both materials show high crystallinity, allowing for atomic resolution structure determination using three-dimensional electron diffraction, and the similarity of their fluorescence properties shows the electronic structures of pyrene-based extended structures mostly depends on the in-plane structures, which is supported by density functional theory calculations. These two pyrene-based extended structures also show different fluorescence responses to organic vapors due to different pore environments. The current work shows the potential of noncovalent interactions in the reticular design of functional organic materials.

Three-dimensional Covalent Organic Framework with Dense Lithiophilic Sites as Protective Layer to Enable High-Performance Lithium Metal Battery.

Lithium (Li) metal batteries with remarkable energy densities are restrained by short lifetime and low Coulombic efficiency (CE), resulting from the accumulative Li dendrites and dead Li during cycling. Here, we prepared a new three-dimensional (3D) covalent organic framework (COF) with dense lithiophilic sites (heteoatom weight contents of 32.32wt%) as an anodic protective layer of Li metal batteries. The 3D COF was synthesized using a [6+4] synthesis strategy by inducing flexible 6-connected cyclotriphosphazene derivative aldehyde and 4-connected porphyrin-based tetraphenylamines. Both phosphazene and porphyrin rings in the COF served as electron-rich and lithiophilic sites, enhancing a homogeneous Li+ flux via 3D direction towards highly smooth and compact Li deposition. The Li/Por-PN-COF-Cu cells achieved a record average CE of 99.1% for 320 cycles with smooth Li deposition. Meanwhile, the abundant lithiophilic sites can promote fast Li+ transport with Li+ transference number of 0.87, enabling LiFePO4 full cell with stable stripping/plating processes even at a harsh rate of 5 C. Theoretical calculations revealed that the strong interaction force between Li+ and the COF facilitated the dissolution of Li+ from the electrolyte, and the low migration barrier of 1.08 eV indicated a favorable interaction between the Li+ ions and the π-electron system.

Three‐dimensional Covalent Organic Framework with Dense Lithiophilic Sites as Protective Layer to Enable High‐Performance Lithium Metal Battery

Lithium (Li) metal batteries with remarkable energy densities are restrained by short lifetime and low Coulombic efficiency (CE), resulting from the accumulative Li dendrites and dead Li during cycling. Here, we prepared a new three‐dimensional (3D) covalent organic framework (COF) with dense lithiophilic sites (heteoatom weight contents of 32.32wt%) as an anodic protective layer of Li metal batteries. The 3D COF was synthesized using a [6+4] synthesis strategy by inducing flexible 6‐connected cyclotriphosphazene derivative aldehyde and 4‐connected porphyrin‐based tetraphenylamines. Both phosphazene and porphyrin rings in the COF served as electron‐rich and lithiophilic sites, enhancing a homogeneous Li+ flux via 3D direction towards highly smooth and compact Li deposition. The Li/Por‐PN‐COF‐Cu cells achieved a record average CE of 99.1% for 320 cycles with smooth Li deposition. Meanwhile, the abundant lithiophilic sites can promote fast Li+ transport with Li+ transference number of 0.87, enabling LiFePO4 full cell with stable stripping/plating processes even at a harsh rate of 5 C. Theoretical calculations revealed that the strong interaction force between Li+ and the COF facilitated the dissolution of Li+ from the electrolyte, and the low migration barrier of 1.08 eV indicated a favorable interaction between the Li+ ions and the π‐electron system.

Functionalization of Covalent Organic Frameworks with Cyclopentadienyl Cobalt for C2H2/CO2 Separation

Emerging covalent organic frameworks (COFs) have received great attention for their unique features, but the limited building blocks restrict their structural diversity and performance exploration. Reticular chemistry provides guidance for the structural expansion and performance regulation of COFs. Herein, we constructed two novel two‐dimensional (2D) COFs functionalized with cyclopentadienyl cobalt, denoted as UPC‐COF‐1 and UPC‐COF‐2, via [4+2] imine condensation with diamine building blocks of different length. Theoretical simulations combined with experimental results reveal that UPC‐COF‐1 with shorter building blocks, narrower pore sizes, and stronger host‐guest interactions has better C2H2/CO2 separation performance. In addition, UPC‐COF‐1 can maintain separation stability in the presence of water vapor and methane impurities. This work provides a new evidence for the performance regulation of isoreticular COFs with modular and tunable building blocks.

Functionalization ofCovalent Organic Frameworks with Cyclopentadienyl Cobalt for C2H2/CO2 Separation.

Emerging covalent organic frameworks (COFs) have received great attention for their unique features, but the limited building blocks restrict their structural diversity and performance exploration. Reticular chemistry provides guidance for the structural expansion and performance regulation of COFs. Herein, we constructed two novel two-dimensional (2D) COFs functionalized with cyclopentadienyl cobalt, denoted as UPC-COF-1 and UPC-COF-2, via [4+2] imine condensation with diamine building blocks of different length. Theoretical simulations combined with experimental results reveal that UPC-COF-1 with shorter building blocks, narrower pore sizes, and stronger host-guest interactions has better C2H2/CO2 separation performance. In addition, UPC-COF-1 can maintain separation stability in the presence of water vapor and methane impurities. This work provides a new evidence for the performance regulation of isoreticular COFs with modular and tunable building blocks.

Benzobisoxazole-based covalent organic frameworks for efficient photocatalytic oxidation

Covalent organic frameworks, as an emerging porous crystalline material, have attracted significant interest in heterogeneous photocatalysis, due to their tunable structure, large specific surface area, high chemical stability, and extendable π-conjugated skeleton. In this study, 4,4′-(2,6-dimethylbenzo[1,2-d:4,5-d′]bis(oxazolyl)-4,8-diyl)dianiline (OZDL) and benzene-1,3,5-tricarboxaldehyde (BTCA) were utilized to construct 2D covalent organic frameworks OZBT-COF through aldehyde-amine polycondensation reaction under solvothermal conditions. Considering the high crystallinity, chemical stability, and outstanding photophysical properties, the benzobisoxazole-containing OZBT-COF was further employed as a photocatalyst for the synthesis of the benzothiazole derivatives and the oxidation of N-substituted tetrahydroisoquinolines. The catalyst system exhibited high photocatalytic activity, moderate substrate applicability, excellent stability and recyclability. The suitable band gap, efficient separation of photogenerated charge carriers, and enhancing mass transport inside the porous catalyst could be contributed to superior photocatalytic performance. This work provides valuable insights into the structure–function correlations of COFs-based photocatalysts, and further demonstrates promising opportunities for developing COF photocatalysts with practical applications.

Totally conjugated and coplanar covalent organic frameworks as photocatalysts for water purification: Reduction of Cr (VI) while oxidizing water borne organic pollutants

Covalent organic frameworks (COFs) have emerged as photocatalytic materials with bandgaps in the visible region. Imine-based COFs, which have been extensively explored, often suffer from limited stability and poor conjugation, hindering their photocatalytic activities. The chemical and hydrolytic stability and the photocatalytic performance of COFs is drastically enhanced by constructing 2D COFs that are fully conjugated in the x,y plane, that have alternating donor–acceptor (D-A) units for better charge separation and that have enhanced conjugation in the z-axis by p-orbital overlap by using highly planar building blocks. In this study, we introduce three highly crystalline sp2 COFs that are able to photocatalyticlly reduce highly toxic Cr (VI) species to much less toxic and easily removable Cr (III) residues, while simultaneously oxidizing water borne organic pollutants. One of them, the TEB-COF, with the integration of the acetylene group, exhibited excellent photocatalytic activity due to its superior planarity and extended conjugation. TEB-COF is able to completely remove the model dye Rhodamine B and Cr (VI) (10 mg/L) in less than 30 min. This research provides valuable insights into the development of recyclable metal-free photocatalysts for wastewater treatment.

Photodual-Responsive Anthracene-Based 2D Covalent Organic Framework for Optoelectronic Synaptic Devices.

To facilitate the development of efficient neuromorphic perception and computation, it is crucial to explore optoelectronic synaptic devices that integrate perceptual and computational capabilities. Various materials such as oxide semiconductors, conjugated organic polymers, transition metal sulfides, perovskite materials, and metal nanoparticles, along with their composites, are utilized in constructing these devices. However, optoelectronic synaptic devices based on 2D covalent organic frameworks (COFs) is rarely reported. In this study, an anthracene-based 2D COF (COF-DaTp) film is prepared using a room-temperature interface-confined strategy and utilized it as the active layer in an optoelectronic synaptic device with an Al/COF-DaTp/ITO configuration. The device demonstrated dual optoelectronic modulation, exhibiting significant optoelectronic resistive switching in response to light pulses, achieving 32 photoconductive states. Moreover, it exhibited history-dependent memristive behavior in voltage scans and electrical pulses, with a comparable diversity of 32 conductive states. The photodual-responsive properties of the COF-DaTp-based synaptic device enable it to simultaneously perform optical sensing and basic image denoising and recognition tasks, significantly enhancing recognition accuracy and reducing the number of training epochs compared to datasets without noise mitigation. This work opens the door for the application of 2D COF-based optoelectronic synaptic devices in visual computational processing.

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.

Synergistic effect of 2D covalent organic frameworks confined 0D carbon quantum dots film: Toward molecularly imprinted cathodic photoelectrochemical platform for detection of tetracycline

The development of high photoactive cathode materials combined with the formation of a stable interface are considered important factors for the selective and sensitive photoelectrochemical (PEC) detection of tetracycline (TC). Along these lines, in this work, a novel type II heterostructure composed of two-dimensional (2D) covalent organic frameworks confined to zero-dimensional (0D) carbon quantum dots (CDs/COFs) film was successfully synthesized using the rapid in-situ polymerization method at room temperature. The PEC signal of CDs/COFs was significantly amplified by improving the light absorption and electron transfer capabilities. Furthermore, a cathodic molecularly imprinted PEC sensor (MIP-PEC) for the detection of TC was constructed through fast in-situ Ultraviolet (UV) photopolymerization on the electrode. Finally, a “turn-off” PEC cathodic signal was achieved based on the selective recognition of the imprinted cavity and the mechanism of steric hindrance increase. Under optimal conditions, the proposed sensor demonstrated a wide linear relationship with TC in the concentration range of 5.00 × 10−12–1.00 × 10−5 M, with a detection limit as low as 6.00 × 10−13 M. Meanwhile, excellent stability, selectivity, reproducibility, and applicability in real river samples was recorded. Our work provides an effective and rapid in situ construction method for fabricating highly photoactive cathode heterojunctions and uniform stable selective MIP-PEC sensing interfaces, yielding accurate antibiotics detection in the environment.

Homochiral Covalent Organic Frameworks with Superhelical Nanostructures Enable Efficient Chirality‐Induced Spin Selectivity

AbstractDespite significant advancements in fabricating covalent organic frameworks (COFs) with diverse morphologies, creating COFs with superhelical nanostructures remains challenging. We report here the controlled synthesis of homochiral superhelical COF nanofibers by manipulating pendent alkyl chain lengths in organic linkers. This approach yields homochiral 3D COFs 13‐OR with a 10‐fold interpenetrated diamondoid structure (R=H, Me, Et, nPr, nBu) from enantiopure 1,1′‐bi‐2‐naphthol (BINOL)‐based tetraaldehydes and tetraamine. COF‐13‐OEt exhibits macroscopic chirality as right‐handed and left‐handed superhelical fibers, whereas others adopt spherical or non‐helical morphologies. Time‐tracking shows a self‐assembly process from non‐helical strands to single‐stranded helical fibers and intertwined superhelices. Ethoxyl substituents, being of optimal size, balance solvophobic effects and intermolecular interactions, driving the formation of superhelical nanostructures, with handedness determined by BINOL chirality. The superhelical nature of these materials is evident in their chiral recognition and spin‐filter properties, showing significantly improved enantiodiscrimination in carbohydrate binding (up to six times higher enantioselectivity) and a remarkable chiral‐induced spin selectivity (CISS) effect with a 48–51 % spin polarization ratio, a feature absent in non‐helical analogs.

Aptamer-Conjugated Covalent-Organic Framework Nanochannels for Selective and Sensitive Detection of Aflatoxin B1.

Sensitive and selective detection of trace aflatoxin B1 (AFB1) in foods is of great importance to guarantee food safety and quality but still challenging because of its trace amount and the interference from the complex food matrix. Here, we report the integration of aptamer (Apt) and an ordered 2D covalent organic framework (COF) to solid-state anodic aluminum oxide (AAO) nanochannels (Apt/COF/AAO) for selective and sensitive detection of trace AFB1. The high specificity of Apt for AFB1 led to a selective change in the surface charge of Apt/COF/AAO and in turn the current change of the nanochannel, permitting the selective and sensitive determination of trace AFB1 in complex food samples. The developed nanofluidic sensor gave a wide linear range (1-500 pg mL-1), low detection limit (0.11 pg mL-1), and good precision (relative standard deviation of 1.5% for 11 replicate determinations of 100 pg mL-1). In addition, the developed sensor was successfully used for the detection of AFB1 in food samples with the recovery of 86.9%-102.5%. The coupling of Apt-conjugated 2D COF with an AAO nanochannel provides a promising way for sensitive and selective determination of food contaminants in complex samples.

Azobenzene-Bridged Covalent Organic Frameworks Boosting Photocatalytic Hydrogen Peroxide Production from Alkaline Water: One Atom Makes a Significant Improvement.

Covalent organic frameworks (COFs) have been demonstrated as promising photocatalysts for hydrogen peroxide (H2O2) production. However, the construction of COFs with new active sites, high photoactivity, and wide-range light absorption for efficient H2O2 production remains challenging. Herein, we present the synthesis of a novel azobenzene-bridged 2D COF (COF-TPT-Azo) with excellent performance on photocatalytic H2O2 production under alkaline conditions. Notably, although COF-TPT-Azo differs by only one atom (-N=N- vs. -C=N-) from its corresponding imine-linked counterpart (COF-TPT-TPA), COF-TPT-Azo exhibits a significantly narrower band gap, enhanced charge transport, and prompted photoactivity. Remarkably, when employed as a metal-free photocatalyst, COF-TPT-Azo achieves a high photocatalytic H2O2 production rate up to 1498 μmol g-1 h-1 at pH = 11, which is 7.9 times higher than that of COF-TPT-TPA. Further density functional theory (DFT) calculations reveal that the -N=N- linkages are the active sites for photocatalysis. This work provides new prospects for developing high-performance COF-based photocatalysts.

Dynamic Two-Dimensional Covalent Organic Frameworks with Large Solvent-Induced Lattice Expansion.

Dynamic covalent organic frameworks (COFs) can switch reversibly between crystalline phases with different unit cell parameters and porosities upon physisorption of guest molecules. While impressive changes in unit cell volumes have been realized for three-dimensional frameworks, the solvent-induced volume changes of two-dimensional (2D) COFs have remained comparably small. We have now developed a series of 2D COFs where we systematically varied the length of the interconnecting bridge units. The optimized materials achieve solvent-induced expansions of up to 85% relative to the volume of the solvent-free contracted COFs. These structural changes are fully reversible and the frameworks fully retain their high degree of crystalline order. This study introduces a versatile design strategy for dynamic 2D COFs, which could enable future applications of these materials in gas separation and sensing.

Single-Crystalline 3D Covalent Organic Frameworks with Exceptionally High Specific Surface Areas and Gas Storage Capacities.

Single-crystalline covalent organic frameworks (COFs) are highly desirable toward understanding their pore chemistry and functions. Herein, two 50-100 μm single-crystalline three-dimensional (3D) COFs, TAM-TFPB-COF and TAPB-TFS-COF, were prepared from the condensation of 4,4',4″,4‴-methanetetrayltetraaniline (TAM) with 3,3',5,5'-tetrakis(4-formylphenyl)bimesityl (TFPB) and 3,3',5,5'-tetrakis(4-aminophenyl)bimesityl (TAPB) with 4,4',4″,4‴-silanetetrayltetrabenzaldehyde (TFS), respectively, in 1,4-dioxane under the catalysis of acetic acid. Single-crystal 3D electron diffraction reveals the triply interpenetrated dia-b networks of TAM-TFPB-COF with atom resolution, while the isostructure of TAPB-TFS-COF was disclosed by synchrotron single-crystal X-ray diffraction and synchrotron powder X-ray diffraction with Le Bail refinements. The nitrogen sorption measurements at 77 K disclose the microporosity nature of both activated COFs with their exceptionally high Brunauer-Emmett-Teller surface areas of 3533 and 4107 m2 g-1, representing the thus far record high specific surface area among imine-bonded COFs. This enables the activated COFs to exhibit also the record high methane uptake capacities up to 28.9 wt % (570 cm3 g-1) at 25 °C and 200 bar among all COFs reported thus far. This work not only presents the structures of two single-crystalline COFs with exceptional microporosity but also provides an example of atom engineering to adjust permanent microporous structures for methane storage.

Insights into the Biological Activity and Bio-Interaction Properties of Nanoscale Imine-Based 2D and 3D Covalent Organic Frameworks.

Covalent Organic Frameworks (COFs) emerged as versatile materials with promising potential in biomedicine. Their customizable functionalities and tunable pore structures make them valuable for various biomedical applications such as biosensing, bioimaging, antimicrobial activity, and targeted drug delivery. Despite efforts made to create nanoscale COFs (nCOFs) to enhance their interaction with biological systems, a comprehensive understanding of their inherent biological activities remains a significant challenge. In this study, a thorough investigation is conducted into the biocompatibility and anti-neoplastic properties of two distinct imine-based nCOFs. The approach involved an in-depth analysis of these nCOFs through in vitro experiments with various cell types and in vivo assessments using murine models. These findings revealed significant cytotoxic effects on tumor cells. Moreover, the activation of multiple cellular death pathways, including apoptosis, necroptosis, and ferroptosis is determined, supported by evidence at the molecular level. In vivo evaluations exhibited marked inhibition of tumor growth, associated with the elevated spontaneous accumulation of nCOFs in tumor tissues and the modulation of cell death-related protein expression. The research contributes to developing a roadmap for the characterization of the intricate interactions between nCOFs and biological systems and opens new avenues for exploiting their therapeutic potential in advanced biomedical applications.

Modulating Pore Wall Chemistry Empowers Sonodynamic Activity of Two-Dimensional Covalent Organic Framework Heterojunctions for Pro-Oxidative Nanotherapy.

Covalent organic frameworks (COFs) have garnered growing attracted interest in the field of biomedicine; however, their application in sonodynamic therapy remains underexplored due to limited understanding of their intrinsic activity and structure-property relationships. Here, we present a pore wall chemistry modulation strategy for empowering sonodynamic activity to two-dimensional (2D) COF heterojunctions through in situ growth of COFs on bismuth oxycarbonate nanosheets (B NSs). Compared to the negligible sonodynamic effects observed in the pristine B NSs, the 2D heterojunction with vinyl-decorated COF pore walls demonstrates a 3.6-fold enhancement in sonocatalytic singlet oxygen generation. This performance also significantly outperforms that of isoreticular COFs functionalized with methoxy or non-substituted groups. Mechanistic studies reveal that the vinyl groups in the BC heterojunction facilitate the separation and transfer of charge carriers while also enhancing the adsorption of oxygen molecules. Furthermore, peroxymonosulfate (PMS) loading into the porous COFs boosts the therapeutic efficacy of antitumor nanotherapy via sonocatalytic dual oxidative species generation. These findings underscore the critical role of pore wall chemistry in modulating the sonocatalytic properties of COFs, and advance the development of COF-based sonosensitizers for pro-oxidative applications.

Non-Noble Metal Anchored 2D Covalent Organic Framework for Ambient CO2 Fixation to High-Value Compounds.

The catalytic functionalization of CO2 into high-value compounds comprises a promising approach to mitigate its atmospheric content and sustainable generation of fine chemicals. Herein, we report application of a crystalline, nano-porous 2D COF (ET-BP-COF) for utilization of CO2. The ET-BP-COF features a unique 2D kagome (kgm) topology composed of hexagonal and triangular 1D channels decorated with bipyridine sites, which were exploited for covalent anchoring of eco-friendly Cu(I) by post-synthetic method. The Cu(I) engrafted COF was applied as a recyclable catalyst for coupling CO2 with alkynes to generate two high-value compounds, α-alkylidene cyclic carbonates (α-ACCs) and 2-oxazolidinones. Notably, Cu(I)@ET-BP-COF demonstrated excellent catalytic performance for transforming propargylic amine and CO2 to 2-oxazolidinone, an essential building block for antibiotics. Besides, an efficient transformation of propargylic alcohols to generate α-ACCs, valuable commodity chemicals, has been achieved by utilizing carbon dioxide. Further, detailed theoretical simulations disclosed the insight mechanistic path of Cu(I) catalyzed coupling of CO2 with alkynes to produce 2-oxazolidinones and α-ACCs. Significantly, Cu(I)@COF was reusable for multiple cycles without losing framework rigidity and catalytic performance. This study showcases the potential application of ET-BP-COF for stable anchoring of eco-friendly metals as catalytic sites for effective utilization of CO2 to produce two high-value products.

Rapid yet Controlled Synthesis of 2D Covalent Organic Framework Nanocapsules as High-Performance Photocatalytic Carriers.

Synthesis and assembly of two-dimensional (2D) polymeric materials present a tricky trade-off between the high reaction rate and precise morphology control. Here we report a nanoconfined synthesis of imine-based 2D covalent organic frameworks (COFs) at the interface of oil-in-water (O/W) emulsion droplets stabilized by cationic surfactants. Highly uniform nanocapsules (NCs) could be prepared without adding extra catalysts at room temperature in just 4.5 h at a yield of 86%. The NCs have tunable average diameters and shell thicknesses, depending on the monomer and surfactant types/concentrations. Their BET-specific surface areas are up to 139.0 m2/g, mainly contributedby narrowly-distributed mesopores at ~5.0 nm and micropores at 1.4 nm.The surfactant plays the role of a catalyst during the reaction and interestingly, it also regulates the formation of mesopores and their sizes. Both theoretical and experimental studies confirm that the reaction has been accelerated by two orders of magnitude at the microdroplet interface, compared to that without emulsification. The resulting NCs could be well dispersed in water, and they have been demonstrated to be highly efficient nanocatalystsin application of water-based hydrogen evolution.Such microdroplet interface-confined synthesis may facilitate the future development of 2D polymeric materials for more advanced applications.