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Abstract Hierarchically porous monolithic silica shows promise as a carrier material for immobilized organocatalysts. Conventional analysis usually includes physisorption, infrared spectroscopy and elemental analysis, among others, to elucidate the pore space and degree of functionalization of the material. However, these methods do not yield information about the spatial distribution of the organic species inside the monolithic reactor. In this work, time‐of‐flight secondary ion mass spectrometry has been applied to characterize the surface of organically functionalized silica monoliths. Cross sections of a silica monolith functionalized with 4‐dimethylaminopyridine were analyzed and the results were compared with physisorption and elemental analysis experiments of the same material. This way, insight into the radial distribution of the catalyst could be achieved, which might assist in interpreting the performance of such reactors in heterogeneous flow catalysis.

Abstract Mesoporous materials find widespread applications due to their high specific surface area, contributing to enhanced performance. Scanning electron microscopy (SEM) observation of mesoporous materials provides valuable insights into their mesostructures. However, direct observation of the outermost surfaces, which often dictate material properties, remains challenging, especially for highly insulating and fragile compounds. In this study, utilizing SEM observation with ultra‐low‐voltage acceleration directed by Gemini column is proposed to achieve direct surface imaging of mesoporous organic materials with highly insulating and fragile characteristics. By observing mesostructured polymers obtained through a soft‐templating method without washing, stuffed pores are identified allowing the differentiation of micelle templates and polymer walls. Moreover, leveraging SEM measurements, a polymerization mechanism is proposed for dopamine on the polymer micelles adhered to the graphene oxide nanosheets. These findings demonstrate the potential of SEM measurements with ultra‐low accelerating voltage in facilitating surface observations of polymer‐derived nanomaterials characterized by high insulating properties and a fragile framework.

Abstract Novel mesoporous silicates modified with imidazolium cation were applied as the support for peroxotungstate. Stepwise introduction of multiple functional groups to SBA‐15 was achieved by the combination of the direct and post‐synthesis procedures. The co‐condensation of tetraethoxysilane and 3‐(imidazolyl‐1‐yl)‐propyltriethoxysilane in the presence of the micelles of an amphiphilic surfactant yields the hydrophilic SBA‐15 type silicate support with the imidazole modifier locating into the mesopores. The hydrophobic environment of the supports was imparted by capping the residual silanols on the silicate surface with trimethylsilyl groups. The fluoroalkyl‐ or alkyl‐imidazolium cation‐anchored supports were derived from the corresponding imidazole‐functionalized precursors. The anion‐exchanging reaction between peroxytungstate and the imidazolium cation‐anchored supports yielded the corresponding tungstate‐immobilized catalysts. The hydrophilic catalyst with the fluoroalkyl‐imidazolium mediated alkene epoxidation with H2O2 in less polar solvents. The hydrophobic one, in contrast, produced diol through the epoxidation and following hydration in an aqueous solvent by the action of the highly Lewis acidic tungsten. The hydrophobic catalysts had the advantage of being more tolerant than hydrophilic catalysts, as evidenced by reusability tests. The activities of the alkyl‐imidazolium catalysts were lower than those of the corresponding fluoroalkyl‐imidazolium catalysts, indicating that the local structures surrounding the tungstate site affected the catalytic performance.

Pseudocapacitive materials with surface‐redox reactions are capable of realizing high capacities at ultrahigh rates; however, it remains a challenge in the synthesis of active components with high surface area to boost surface‐redox sodiation but restrain side reactions. Herein, a two‐step, topochemical synthesis of 2D mesoporous TiN (2D‐meso‐TiN) with high surface area and rich mesoporosities is presented. It is demonstrated that the sodium‐ion storage mechanism of TiN anode is based on the existence of surficial titanium oxides via redox reactions between Ti4+ and Ti3+. The interconnected, highly conductive 2D‐meso‐TiN with high surface area largely increases the pseudocapacitive capacities, leading to a high capacity of 160/93 mAh g−1 at 0.1/10 A g−1, which is much higher than 2D‐TiN (120/72 mAh g−1) and commercial TiN nanoparticles (57/30 mAh g−1). The surface‐redox (de)sodiation undergoes no destruction of crystalline TiN, which enables high initial coulombic efficiency and long‐term cycles. Furthermore, a novel hybrid sodium‐ion capacitor consisting of 2D‐meso‐TiN anode and Na3V2(PO4)3 cathode is assembled without any presodiation treatments. The hybrid capacitor delivers both high energy density (94 Wh kg−1 at 64 W kg−1) and high power density (38 Wh kg−1 at 4.4 kW kg−1), as well as long cycling stability.

Abstract Compartmentalization is a ubiquitous feature of life, with a membrane interface that regulates molecular transport and exhibits bioactivities. An artificial enzyme‐integrated membrane cascade system can mimic such interactive properties across different length scales for in vitro application. Here, it is shown that a reticulated nanoporous framework membrane with nano‐caged enzymes presents the first modular macroscale platform for the compartmentalized biocatalytic system interfaced with an external medium. Catalase (CAT)‐integrated polyurea membrane scaffold is prepared by a simple pressurization procedure for a model cyclic cascade of glucose oxidase/catalase (GOx/CAT). The bicontinuous nanoporous membrane readily constructs a compartmentalized system interfacing the glucose/GOx solution and the external environment and mediates glucose oxidation by a cascade reaction under anaerobic or aerobic conditions. Furthermore, the membrane compartment exhibits multiple bioactive capabilities and barrier properties, including hydrogen peroxide detoxification, in situ oxygen generation, and protease exclusion. This work suggests a new strategy toward a robust modular biocatalytic membranous interface to mediate biochemical reaction cascades occurring in a compartment interfaced to an external environment, promising for potential applications in biohybrid devices embedded with tissues and cells.

Metal oxide nanocrystals/mesoporous carbon composite materials are promising in the energy storage field. However, the construction of stoichiometric ternary nanocrystals‐functionalized mesoporous carbon materials remains a great challenge. Herein, the synthesis of ultradispersed and ultrasmall LiTiO2 nanocrystals/ordered mesoporous carbon composites via a chelation‐mediated multicomponent coassembly strategy is reported. In this case, the self‐assembly into ordered mesostructures and the crystallization of nanoparticle processes can be decoupled by the molecular chelate strategy where citrate ligands can effectively inhibit the hydrolysis and phase separation of metal oxide precursors and confine the crystallization into nanocrystals without aggregation. The obtained 33%‐LiTiO2–OMC composites present a high specific surface area (≈912 m2 g−1), a large pore volume (≈0.62 cm3 g−1), a uniform pore size (≈4.1 nm), and ultradispersed LiTiO2 nanocrystals (≈3 nm). When loading 60% sulfur, the composites exhibit a high reversible capacity (966 mAh g−1 after 100 cycles at 0.5C), an excellent rate capacity (700 mAh g−1 at 5C), and a long‐term cycling performance (63% retention after 1000 cycles at 5C). This method is very simple and reproducible, which paves a new way for the design and synthesis of functional mesoporous materials.

Abstract 2D porous polymers have received great attention in many fields. Particularly, 2D porous polymers are considered as potential electrode materials for supercapacitors. However, the controllable synthesis of 2D porous polymers is not only faced with the difficulty in precisely controlling the reaction dynamics but is also challenged by the complex pore structure fabrication. In this paper, a swelling‐induced structural transformation strategy for the construction of 2D porous polypyrrole/MXene heterostructures (2D porous PPy/MXene) is proposed. The obtained 2D porous PPy/MXene samples own similar chemical compositions with adjusted pore structures (cylindrical mesostructure, spherical mesostructure, and spherical macrostructure), high specific surface areas (≈129–188 m2 g−1), and tunable pore sizes (≈7.8–52 nm). Due to the fast transport and diffusion of electrolytes and more electrode/electrolyte interface offered by cylindrical mesopores with high specific surface areas, the 2D porous PPy/MXene shows superior supercapacitor performances. This work sheds light on the effect of pore structures on supercapacitor performances of 2D porous polymers, and also provides clues for the fabrication of 2D porous polymers with tailorable pore structures as high‐performance energy storage materials.

Constructing nanoreactors with multiple active sites in well-defined crystalline mesoporous frameworks is an effective strategy for tailoring photocatalysts to address the challenging of CO 2 reduction. Herein, one-dimensional (1-D) mesoporous single-crystal TiO 2 nanorod (MS-TiO 2 -NRs, ≈110 nm in length, high surface area of 117 m 2 g -1 , and uniform mesopores of ≈7.0 nm) based nanoreactors are prepared via a droplet interface directed-assembly strategy under mild condition. By regulating the interfacial energy, the 1-D mesoporous single-crystal TiO 2 can be further tuned to polycrystalline fan- and flower-like morphologies with different oxygen vacancies (O v ). The integration of single-crystal nature and mesopores with exposed oxygen vacancies make the rod-like TiO 2 nanoreactors exhibit a high-photocatalytic CO 2 reduction selectivity to CO (95.1%). Furthermore, photocatalytic cascade nanoreactors by in situ incorporation of CuW 6 O 24 (W-Cu) clusters onto MS-TiO 2 -NRs via O v are designed and synthesized, which improved the CO 2 adsorption capacity and achieved two-step CO 2 -CO-CH 4 photoreduction. The second step CO-to-CH 4 reaction induced by W-Cu sites ensures a high generation rate of CH 4 (420.4 µmol g -1 h -1 ), along with an enhanced CH 4 selectivity (≈94.3% electron selectivity). This research provides a platform for the design of mesoporous single-crystal materials, which potentially extends to a range of functional ceramics and semiconductors for various applications., (© 2024 Wiley‐VCH GmbH.)

Flexible porous materials have gained considerable interest for their potential applications in selective absorption and controlled release/storage of specific molecules or compounds. Here, nanoscrolls are proposed as a type of inorganic solids with reversibly flexible mesopores. Nanoscrolls exhibit a rolled-up structure composed of nanosheets with a 1D rod-like morphology, possessing two distinct nanospaces. The first space comprises 1D tubular mesopores located at the center of the rod, while the second space exists in the interlayer regions on the wall of the mesopore, resulting from the layer stacking caused by the scrolling of nanosheets. By replacing the interlayer cations on the nanoscroll walls with other cations, a drastic alteration in the size of the 1D mesopores is observed. For instance, exchanging bulky dodecylammonium cations with small NH 4 + cations leads to a substantial change in pore size, with differences ranging from 10 to 20 nm-a notably larger variation compared to previous reports on flexible porous materials. Importantly, the alteration of pore size induced by the exchange reaction is found to be reversible. This reversible alteration in pore size holds promise for applications in host-guest chemistry involving large moieties such as nanoparticles and enzymes., (© 2024 The Author(s). Small published by Wiley‐VCH GmbH.)

This study demonstrated a simple and innovative way of using the direct de novo synthesis to fabricate the mesoporous structure and diverse functionality of ZIF-8 for environmental cleanup and gas storage applications. By introducing different ligands, we have developed a version of ZIF-8 that could better capture carbon dioxide (CO 2 ) and iodine. The ZIF-8 was successfully designed to have the hierarchical and mesoporous structure with the functional groups of amine and thiol groups by adjusting the pKa values (from 8 to 12) of ligand instead of the original ligand, 2-methyl imidazole (Hmim, pK a ~14.2). The modulation of ZIF-8 particle size, porosity, and functional characteristics was achieved through varied ligands and their concentrations, streamlined into a single and room-temperature synthesis condition. The resulting ZIF-8 materials exhibit intricate hierarchical architectures and a high density of functional groups, significantly enhancing molecular diffusion and accessibility. Among the developed materials, ZIF-8-AS, featuring both amine and thiol groups, demonstrates the fastest adsorption kinetics and a twofold increase in iodine adsorption capacity (q m =1101.5 mg g -1 ) compared to ZIF-8 (q m =514.3 mg g -1 ). Furthermore, the hierarchical mesoporosity of ZIF-8-A-10.1 improves CO 2 adsorption to 1.0 mmol g -1 at 298 K, which is 1.3 times higher than that of the microporous ZIF-8., (© 2024 Wiley-VCH GmbH.)

In response to the ever increasing need to develop more efficient and sustainable methods for removing heavy metal contaminants from aqueous systems, the following article reports on the design of highly mesoporous alginate-derived materials (Starbon ® ) and their application to the adsorption of heavy metals. Using the Starbon ® process to expand, dry and pyrolyse an inherently porous polysaccharide precursor, it was possible to produce mesoporous materials (BJH mesopore volumes 0.81-0.94 cm 3  g -1 ) with large surface areas (157-297 m 2  g -1 ) across a range of low pyrolysis temperatures (200-300 °C). The mechanisms of thermal decomposition were explored in terms of chemical and structural changes using N 2 -sorption porosimetry, thermogravimetric analysis, titration, FT-IR spectroscopy and 13 C NMR spectroscopy. It was found that, as a result of intermolecular dehydration and crosslinking, sufficient chemical stability is obtained by the intermediate temperature of 250 °C, with limited improvement seen at higher temperatures. In addition, the materials retained large metal adsorption capacities (0.70-1.72 mmol g -1 ) as well as strong selectivity for Cu 2+ ions (over Co 2+ and Ni 2+ ), as compared to commercial petrochemical-derived cation exchange resin Amberlite™ Mac 3H. Thus, highlighting the potential of Starbon ® materials as a sustainable answer to the widespread problem of heavy metal-contaminated wastewaters., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Abstract In this paper, we highlight the uniqueness of nanoporous film‐coated electrodes as electrochemical sensing platforms. Specifically, we focus on discussing electrodes coated with insulator‐based monolithic films comprising vertically‐oriented, rigid cylindrical nanopores of uniform diameters (2–200 nm). The electrode coating results in the formation of an array of recessed nanodisk electrodes, and thus we named them recessed nanodisk‐array electrodes (RNEs). We first summarize the properties of nanoporous films commonly used for RNE fabrication, including nanoporous anodic alumina membranes, track‐etched polymer membranes, block copolymer‐derived nanoporous films, and mesoporous silica films. Subsequently, we discuss representative works that take advantage of the uniform size/shape of the nanopores for enhancing electrochemical detection selectivity and sensitivity. RNE‐based sensors measure faradaic currents from redox‐active analytes or exogenously‐added electroactive species that penetrate through the nanopores, or those from redox‐active moieties tethered to the surface of the nanopores or underlying electrodes. The enhanced detection selectivity of these sensors is attributed to the preferential partitioning of analytes into the nanopores or steric/electrostatic exclusion of interfering species. In particular, the uniform sizes/shapes of RNE nanopores play key roles in their higher molecular sieving selectivity and also in the better control of the detection selectivity based on electrostatic/chemical interactions. The detection sensitivity of RNE‐based sensors can be improved by tailoring the chemical environments of the nanopores for analyte preconcentration or for steric/electrostatic manipulation of the dynamics of redox‐tagged binding moieties. These unique characteristics of RNEs, in addition to the mitigation of electrode fouling by the nanoporous films, will enable the development of pretreatment‐free electrochemical sensors for complex matrix solutions.

The development of active and selective metal electrocatalysts for complete ethanol oxidation reaction (EOR) into desired C1 products is extremely promising for practical application of direct ethanol fuel cells. Despite some encouraging achievements, their activity and selectivity remain unsatisfactory. In this work, it is reported that 2D PtRhPb mesoporous nanosheets (MNSs) with anisotropic structure and surface-clean metal site perform perfectly for complete EOR electrocatalysis in both three-electrode and two-electrode systems. Different to the traditional routes, a selective etching strategy is developed to produce surface-clean mesopores while retaining parent anisotropy quasi-single-crystalline structure without the mesopore-forming surfactants. This method also allows the general synthesis of surface-clean mesoporous metals with other compositions and structures. When being performed for alkaline EOR electrocatalysis, the best PtRhPb MNSs deliver remarkably high activity (7.8 A mg -1 ) and superior C1 product selectivity (70% of Faradaic efficiency), both of which are much better than reported electrocatalysts. High performance is assigned to multiple structural and compositional synergies that not only stabilized key OH ads intermediate by surface-clean mesopores but also separated the chemisorption of two carbons in ethanol by adjacent Pt and Rh sites, which facilitate the oxidation cleavage of stable C─C bond for complete EOR electrocatalysis., (© 2024 Wiley‐VCH GmbH.)

Ultrasmall mesoporous nanoparticles (<50 nm), a unique porous nanomaterial, have been widely studied in many fields in the last decade owing to the abundant advantages, involving rich mesopores, low density, high surface area, numerous reaction sites, large cavity space, ultrasmall size, etc. This paper presents a review of recent advances in the preparation, functionalization, and applications of ultrasmall inorganic mesoporous nanoparticles for the first time. The soft monomicelles-directed method, in contrast to the hard-template and template-free methods, is more flexible in the synthesis of mesoporous nanoparticles. This is because the amphiphilic micelle has tunable functional blocks, controlled molecule masses, configurations and mesostructures. Focus on the soft micelle directing method, monomicelles could be classified into four types, i.e., the Pluronic-type block copolymer monomicelles, laboratory-synthesized amphiphilic block copolymers monomicelles, the single-molecule star-shaped block copolymer monomicelles, and the small-molecule anionic/cationic surfactant monomicelles. This paper also reviews the functionalization of the inner mesopores and the outer surfaces, which includes constructing the yolkshell structures (encapsulated nanoparticles), anchoring the active components packed on the shell and building an asymmetric Janus architecture. Then, several representative applications, involving catalysis, energy storage, and biomedicines are presented. Finally, the prospects and challenges of controlled synthesis and large-scale applications of ultrasmall mesoporous nanoparticles in the future are foreseen., (© 2024 Wiley‐VCH GmbH.)

Mesoporous honeycomb iron titanate using a sol-gel, evaporation-induced self-assembly method is synthesized. A triblock copolymer, F127, serves as a structure-directing agents, with iron chloride and titanium (IV) isopropoxide as inorganic precursors. The strong intermolecular force of attraction among urea, metal precursors, and polymer led to the formation of the mesoporous honeycomb structure. The study of physicochemical properties using different techniques reveals the formation of microstructures with a remarkable degree of porosity. The amorphous iron titanate outperforms the photochemical generation of H 2 due to its disorderly structural arrangement and incomplete crystal formation. The randomness on the structure provides more area for catalytic reaction by providing more contact with the reactant and superior light absorption capability. The high amount of hydrogen gas, 40.66 mmolg -1 h -1 , is observed in the investigation over 3 h of activity for the iron titanate honeycomb sample. This yield is a more significant amount compared to the obtained for the commercially available TiO 2 (23.78 mmolg -1 h -1 ). The iron titanate materials synthesized with low-cost materials and methods are very effective and have the potential for hydrogen generation., (© 2024 The Authors. Small published by Wiley‐VCH GmbH.)

Deep cracking of bulky hydrocarbons on zeolite-containing catalysts into light products with high activity, desired selectivity, and long-term stability is demanded but challenging. Herein, the efficient deep cracking of 1,3,5-triisopropylbenzene (TIPB) on intimate ZSM-5@AlSBA-15 composites via tandem catalysis is demonstrated. The rapid aerosol-confined assembly enables the synthesis of the composites composed of a continuous AlSBA-15 matrix decorated with isolated ZSM-5 nanoparticles. The two components at various ZSM-5/AlSBA-15 mass ratios are uniformly mixed with chemically bonded pore walls, interconnected pores, and eliminated external surfaces of nanosized ZSM-5. The typical composite with a ZSM-5/AlSBA-15 mass ratio of 0.25 shows superior performance in TIPB cracking with outstanding activity (≈100% conversion) and deep cracking selectivity (mass of propylene + benzene > 60%) maintained for a long time (> 6 h) under a high TIPB flux (2 mL h -1 ), far better (several to tens of times higher) than the single-component and physically mixed catalysts and superior to literature results. The high performance is attributed to the cooperative tandem catalytic process, that is, selective and timely pre-cracking of TIPB to isopropylbenzene (IPB) in AlSBA-15 and subsequently timely diffusion and deep cracking of IPB in nanosized ZSM-5., (© 2024 Wiley‐VCH GmbH.)

The surface of SBA-15 mesoporous silica was modified by N-hydroxyphthalimide (NHPI) moieties acting as immobilized active species for aerobic oxidation of alkylaromatic hydrocarbons. The incorporation was carried out by four original approaches: the grafting-from and grafting-onto techniques, using the presence of surface silanols enabling the formation of particularly stable O-Si-C bonds between the silica support and the organic modifier. The strategies involving the Heck coupling led to the formation of NHPI groups separated from the SiO 2 surface by a vinyl linker, while one of the developed modification paths based on the grafting of an appropriate organosilane coupling agent resulted in the active phase devoid of this structural element. The successful course of the synthesis was verified by FTIR and 1 H NMR measurements. Furthermore, the formed materials were examined in terms of their chemical composition (elemental analysis, thermal analysis), structure of surface groups ( 13 C NMR, XPS), porosity (low-temperature N 2 adsorption), and tested as catalysts in the aerobic oxidation of p-xylene at atmospheric pressure. The highest conversion and selectivity to p-toluic acid were achieved using the catalyst with enhanced availability of non-hydrolyzed NHPI groups in the pore system. The catalytic stability of the material was additionally confirmed in several subsequent reaction cycles., (© 2024 Wiley-VCH GmbH.)

Efficient mass transfer in electrodes is essential for the electrochemical processes of battery charge and discharge, especially at high rates and capacities. This study introduces a 3D electrode design featuring layered double hydroxides (LDHs) nanosheets array grown in situ on a carbon felt surface for flow batteries. The mesoporous structure and surface characteristic of LDH nanosheets, especially, the hydroxyl groups forming a unique "H-bonding-like" geometry with ferrous cyanide ions, facilitate efficient adsorption and ion transport. Thus, the designed LDHs electrode enables the alkaline zinc-iron flow battery to maintain a voltage efficiency of 81.6% at an ultra-high current density of 320 mA cm -2 , surpassing the values reported in previous studies. The energy efficiency remains above 84% after 375 cycles at a current density of 240 mA cm -2 . Molecular dynamics simulations verify the enhanced adsorption effect of LDH materials on active ions, thus facilitating ion transport in the battery. This study provides a novel approach to improve mass transport in electrodes for alkaline flow batteries and other energy storage devices., (© 2023 Wiley‐VCH GmbH.)

Abstract A new delivery microdevice, based on hydrophobic oleic acid‐capped mesoporous silica particles and able to payload release in the presence of surfactants, has been developed. The oleic acid functionalization confers to the system a high hydrophobic character, which avoids cargo release unless surfactant molecules are present. The performance of this oleic‐acid capped microdevice in the presence of different surfactants is presented and its zero‐release operation in the absence of surfactants is demonstrated.

Mesoporous metal nanomaterials (MPMNs) are pivotal in nanotechnology, especially in electrochemical applications, due to their unique structure. Unlike traditional nanomaterials, MPMNs possess hierarchical and mesoporous characteristics, providing more active sites for improved mass and electron transfer. This distinctive composition offers dual benefits, enhancing activity, stability, and selectivity for specific reactions. The intricate architecture, featuring interconnected pores, amplifies surface area, ensuring efficient use of active sites and boosting reactivity in electrocatalytic processes. Additionally, the mesoporous nature promotes superior diffusion kinetics, facilitating better transport of reactants and products. This intricate interplay of structural elements contributes not only to the increased efficiency of electrochemical reactions but also to the extended durability of MPMNs during prolonged usage. This concept focus on the synthesis and design strategies of MPMNs, aligning with the dynamic requirements of diverse electrocatalytic applications. The synergy resulting from these advancements not only accentuates the intrinsic properties of MPMNs but also broadens their scope for practical implementation in emerging fields of electrochemistry., (© 2024 Wiley-VCH GmbH.)

Mesoporous metal oxides exhibit excellent physicochemical properties and are widely used in various fields, including energy storage/conversion, catalysis, and sensors. Although several soft-template approaches are reported, high-temperature calcination for both metal oxide formation and template removal is necessary, which limits direct synthesis on a plastic substrate for flexible devices. Here, a universal synthetic approach that combines thermal activation and oxygen plasma to synthesize diverse mesoporous metal oxides (V 2 O 5 , V 6 O 13 , TiO 2 , Nb 2 O 5 , WO 3, and MoO 3 ) at low temperatures (150-200 °C), which can be applicable to a flexible polymeric substrate is introduced. As a demonstration, a flexible micro-supercapacitor is fabricated by directly synthesizing mesoporous V 2 O 5 on an indium-tin oxide-coated colorless polyimide film. The energy storage performance is well maintained under severe bending conditions., (© 2024 Wiley‐VCH GmbH.)

Ordered mesoporous crystalline frameworks (MCFs), which possess both functional frameworks and well-defined porosity, receive considerable attention because of their unique properties including high surface areas, large pore sizes, tailored porous structures, and compositions. Construction of novel crystalline mesoporous architectures that allows for rich accessible active sites and efficient mass transfer is envisaged to offer ample opportunities for potential energy-related applications. In this review, the rational synthesis, unique structures, and energy applications of MCFs are the main focus. After summarizing the synthetic approaches, an emphasis is placed on the delicate control of crystallites, mesophases, and nano-architectures by concluding basic principles and showing representative examples. Afterward, the currently fabricated components of MCFs such as metals, metal oxides, metal sulfides, and metal-organic frameworks are described in sequence. Further, typical applications of MCFs in rechargeable batteries, supercapacitors, electrocatalysis, and photocatalysis are highlighted. This review ends with the possible development and synthetic challenges of MCFs as well as a future prospect for high-efficiency energy applications, which underscores a pathway for developing advanced materials., (© 2024 Wiley‐VCH GmbH.)

Hierarchical superstructures have novel shape-dependent properties, but well-defined anisotropic carbon superstructures with controllable size, shape, and building block dimensionality have rarely been accomplished thus far. Here, a hierarchical assembly technique is presented that uses spinodal decomposition (SD) to synthesize anisotropic oblate particles of mesoporous carbon superstructure (o-MCS) with nanorod arrays by integrating block-copolymer (BCP) self-assembly and polymer-polymer interface behaviors in binary blends. The interaction of major and minor phases in binary polymer blends leads to the formation of an anisotropic oblate particle, and the BCP-rich phase enables ordered packing and unidirectional alignment of carbon nanorods. Consequently, this approach enables precise control over particles' size, shape, and over the dimensionality of their components. Exploiting this functional superstructure, o-MCS are used as an anode material in potassium-ion batteries, and achieve a notable specific capacity of 156 mA h g -1 at a current density of 2 A g -1 , and long-term stability for 3000 cycles. This work presents a significant advancement in the field of hierarchical superstructures, providing a promising strategy for the design and synthesis of anisotropic carbon materials with controlled properties, offering promising applications in energy storage and beyond., (© 2023 Wiley‐VCH GmbH.)

Abstract The synthesis, characterization, and application of mesoporous materials containing boron–dipyrromethene (BODIPY) moieties that allow the sensitive and selective detection of HgII in aqueous environments by fluorescence enhancement is reported. For this purpose, BODIPY dye I containing a thia‐aza crown ether receptor as the fluorescent probe for the detection of HgII in aqueous environments is encapsulated into mesoporous materials to avoid self‐quenching or aggregation in water. Determination of HgII is accomplished within a few seconds with high selectivity and sensitivity, reaching a limit of detection of 12 ppt. The determination of trace amounts of HgII in natural waters and in fish extracts is demonstrated by using our sensing material. The incorporation of the material into several μ‐PAD strips yields a portable, cheap, quick, and easy‐to‐handle tool for trace HgII analysis in water.

5-Hydroxymethylfurfural (5-HMF) synthesized through glucose conversion requires Lewis acid (L) site for isomerization and Brønsted acid (B) site for dehydration. The objective of this work is to investigate the influence of the metal type of Al-SBA-15-supported phosphates of Cr, Zr, Nb, Sr, and Sn on glucose conversion to 5-HMF in a NaCl-H 2 O/n-butanol biphasic solvent system. The structural and acid property of all supported metal phosphate samples were fully verified by several spectroscopic methods. Among those catalysts, CrPO/Al-SBA-15 provided the best performance with the highest glucose conversion and 5-HMF yield, corresponding to the highest total acidity of 0.65 mmol/g and optimal L/B ratio of 1.88. For CrPO/Al-SBA-15, another critical parameter is the phosphate-to-chromium ratio. Moreover, DFT simulation of glucose conversion to 5-HMF on the surface of the optimized chromium phosphate structure reveals three steps of fructose dehydration on the Brønsted acid site. Finally, the optimum reaction condition, reusability, and leaching test of the best catalyst were determined. CrPO/Al-SBA-15 is a promising catalyst for glucose conversion to high-value-added chemicals in future biorefinery production., (© 2023 Wiley-VCH GmbH.)

Structurally optimized transition metal phosphides are identified as a promising avenue for the commercialization of lithium-sulfur (Li-S) batteries. In this study, a CoP nanoparticle-doped hollow ordered mesoporous carbon sphere (CoP-OMCS) is developed as a S host with a "Confinement-Adsorption-Catalysis" triple effect for Li-S batteries. The Li-S batteries with CoP-OMCS/S cathode demonstrate excellent performance, delivering a discharge capacity of 1148 mAh g -1 at 0.5 C and good cycling stability with a low long-cycle capacity decay rate of 0.059% per cycle. Even at a high current density of 2 C after 200 cycles, a high specific discharge capacity of 524 mAh g -1 is maintained. Moreover, a reversible areal capacity of 6.56 mAh cm -2 is achieved after 100 cycles at 0.2 C, despite a high S loading of 6.8 mg cm -2 . Density functional theory (DFT) calculations show that CoP exhibits enhanced adsorption capacity for sulfur-containing substances. Additionally, the optimized electronic structure of CoP significantly reduces the energy barrier during the conversion of Li 2 S 4 (L) to Li 2 S 2 (S). In summary, this work provides a promising approach to optimize transition metal phosphide materials structurally and design cathodes for Li-S batteries., (© 2023 Wiley-VCH GmbH.)

Methane (CH 4 ), as the vital energy resource and industrial chemicals, is highly flammable and explosive for concentrations above the explosive limit, triggering potential risks to personal and production safety. Therefore, exploiting smart gas sensors for real-time monitoring of CH 4 becomes extremely important. Herein, the Pt-Pd nanoalloy functionalized mesoporous SnO 2 microspheres (Pt-Pd/SnO 2 ) were synthesized, which show uniform diameter (≈500 nm), high surface area (40.9-56.5 m 2 g -1 ), and large mesopore size (8.8-15.8 nm). The highly dispersed Pt-Pd nanoalloys are confined in the mesopores of SnO 2 , causing the generation ofoxygen defects and increasing the carrier concentration of sensitive materials. The representative Pt 1 -Pd 4 /SnO 2 exhibits superior CH 4 sensing performance with ultrahigh response (R a /R g = 21.33 to 3000 ppm), fast response/recovery speed (4/9 s), as well as outstanding stability. Spectroscopic analyses imply that such an excellent CH 4 sensing process involves the fast conversion of CH 4 into formic acid and CO intermediates, and finally into CO 2 . Density functional theory (DFT) calculations reveal that the attractive covalent bonding interaction and rapid electron transfer between the Pt-Pd nanoalloys and SnO 2 support, dramatically promote the orbital hybridization of Pd 4 sites and adsorbed CH 4 molecules, enhancing the catalytic activation of CH 4 over the sensing layer., (© 2023 Wiley-VCH GmbH.)

Metal single-atom catalysts are promising in electrochemical CO 2 reduction reaction (CO 2 RR). The pores and cavities of the supports can promote the exposure of active sites and mass transfer of reactants, hence improve their performance. Here, iron oxalate is added to ZIF-8 and subsequently form hollow carbon nanocages during calcination. The formation mechanism of the hollow structure is studied in depth by controlling variables during synthesis. Kirkendall effect is the main reason for the formation of hollow porous carbon nanocages. The hollow porous carbon nanocages with Fe single atoms exhibit better CO 2 RR activity and CO selectivity. The diffusion of CO 2 facilitated by the mesoporous structure of carbon nanocage results in their superior activity and selectivity. This work has raised an effective strategy for the synthesis of hollow carbon nanomaterials, and provides a feasible pathway for the rational design of electrocatalysts for small molecule activation., (© 2023 Wiley-VCH GmbH.)

Site-selective and partial decoration of supported metal nanoparticles (NPs) with transition metal oxides (e.g., FeO x ) can remarkably improve its catalytic performance and maintain the functions of the carrier. However, it is challenging to selectively deposit transition metal oxides on the metal NPs embedded in the mesopores of supporting matrix through conventional deposition method. Herein, a restricted in situ site-selective modification strategy utilizing poly(ethylene oxide)-block-polystyrene (PEO-b-PS) micellar nanoreactors is proposed to overcome such an obstacle. The PEO shell of PEO-b-PS micelles interacts with the hydrolyzed tungsten salts and silica precursors, while the hydrophobic organoplatinum complex and ferrocene are confined in the hydrophobic PS core. The thermal treatment leads to mesoporous SiO 2 /WO 3-x framework, and meanwhile FeO x nanolayers are in situ partially deposited on the supported Pt NPs due to the strong metal-support interaction between FeO x and Pt. The selective modification of Pt NPs with FeO x makes the Pt NPs present an electron-deficient state, which promotes the mobility of CO and activates the oxidation of CO. Therefore, mesoporous SiO 2 /WO 3-x -FeO x /Pt based gas sensors show a high sensitivity (31 ± 2 in 50 ppm of CO), excellent selectivity, and fast response time (3.6 s to 25 ppm) to CO gas at low operating temperature (66 °C, 74% relative humidity)., (© 2023 Wiley-VCH GmbH.)

Porous carbon is considered an attractive host material for high-energy sulfur electrodes. This study concerns the design of a porous carbon-based sulfur electrode for the formulation of high-energy Li-S batteries. The porous carbon is impregnated with up to 80 vol.% of sulfur and a reduction in both the conductive agent and binder content. Therefore, less solvent can be used during slurry casting to inhibit crack formation following electrode drying. In addition, the utilization of two distinct electrically conducting networks enables reduced battery polarization, resulting in a battery with a capacity of 690 mAh g -1 (even after 100 cycles). Finally, pouch cells are prepared to characterize the practical performance of the optimized cathode. This yields a capacity of 741 mAh and a cathode energy density of 1001 Wh kg -1 . These findings are expected to guide the further development of high-energy-density cathode materials for Li-S batteries., (© 2022 Wiley-VCH GmbH.)

In this study, Cu-SSZ-13 zeolites are successfully coated with mesoporous metal oxides (CeO 2 , Fe 2 O 3 , TiO 2 and SiO 2 ) and prepared as core-shell Cu-SSZ-13@meso-MO x samples with hierarchical pore structure. Compared with Cu-SSZ-13, the catalytic activity and hydrothermal stability of the Cu-SSZ-13@meso-MO x have been greatly improved. The promoting effect of meso-MO x shell on the catalytic activity of Cu-SSZ-13 is mainly attribute to the presence of both microporous and mesoporous structures, the formation of more active isolated Cu 2+ ions and more L-acid sites, and the synergistic effect between Cu-SSZ-13 and meso-MO x interaction. Moreover, all the Cu-SSZ-13@meso-MO x catalysts maintain their activities to a greater extent after hydrothermal aging. The core-shell structure may play a protective role and greatly improve the hydrothermal stability of Cu-SSZ-13. More L-acidic sites and more isolated Cu 2+ ions are preserved under the protection of mesoporous structure., (© 2023 Wiley-VCH GmbH.)

The condensation of biomass-derived molecules has been increasingly utilized as a sustainable strategy for the preparation of high-carbon precursors for high-density fuels, thus stimulating the demand for more efficient catalysts. This study concerns the synthesis of an aluminum-doped mesoporous silica sphere (Al-MSS) catalyst for the conversion of biobased furfural and 2-methylfuran into a C 15 diesel precursor through a hydroxyalkylation/alkylation (HAA) reaction. A series of Al-MSS catalysts with different Si/Al ratios and calcination temperatures is prepared and extensively characterized, among which Al-MSS20-450 (Si/Al=20 : 1, calcined at 450 °C) exhibits unprecedentedly high reaction efficiency in catalyzing HAA reaction, offering a 94 % product yield at 140 °C in 20 min. The catalyst also gives high product yields across a broad temperature range from 80 °C to 140 °C with varied reaction time. Reaction kinetics reveal that both competitive substrate adsorption and temperature-dependent system viscosity affect the reaction efficiencies. Correlations between the catalytic activity and surface acid sites disclose that moderate and strong acid sites are primarily responsible for catalysis. Brønsted and Lewis acid sites are found by poisoning assays to work synergistically to catalyze the reaction, with the former being the primary sites. Finally, the catalyst displays good recycling performance, which further highlights its potential for industrial application., (© 2022 Wiley-VCH GmbH.)

Supported metal catalysts have played an important role in optimizing selective semihydrogenation of alkynes for fine chemicals. There into, nitrogen-doped carbons, as a type of promising support materials, have attracted extensive attentions. However, due to the general phenomenon of random doping for nitrogen species in the support, it is still atremendous challenge to finely identify which nitrogen configuration dominates the catalytic property of alkynes' semihydrogenation. Herein, it is reported that uniform mesoporous N-doped carbon spheres derived from mesoporous polypyrrole spheres are used as supports to immobilized subnanometric Pd clusters, which provide a particular platform to research the influence of nitrogen configurations on the alkynes' semihydrogenation. Comprehensive experimental results and density functional theory calculation indicate that pyridinic nitrogen configuration dominates the catalytic behavior of Pd clusters. The high contents of pyridinic nitrogen sites offer abundant coordination sites, which greatly reduces the energy barrier of the rate-determining reaction step and makes Pd clusters own high catalytic activity. The electron effect between pyridinic nitrogen sites and Pd clusters makes the reaction highly selective. Additionally, the good mesostructures also promote the fast transport of substrate. Based on the above, catalyst Pd@PPy-600 exhibits high catalytic activity (99%) and selectivity (96%) for phenylacetylene (C 8 H 6 ) semihydrogenation., (© 2023 Wiley-VCH GmbH.)

Block copolymers (BCPs) have enduring appeal for its intriguing assembly behaviors. Nevertheless, the unsatisfactory mechanical properties of BCPs make it a problem to fabricate freestanding membranes and hindered practical applications. Herein, a freestanding membrane with tunable pore size is prepared simply by co-assembly of BCPs and subnanometer nanowires (SNWs), combining the abundant function of BCPs and prominent mechanical properties of SNWs. Benefited from synergy of the components and the hierarchical structure, the tensile strength of composite membrane is promoted by two orders of magnitude compared to that of BCPs. With the columnar pores aligning vertically to surfaces and the pore size regulated by processing conditions, the membranes exhibit precise size-selected effect in ultrafiltration of Au nanoparticles (Au NPs) and can distinct NPs with diameter difference as tiny as 5 nm, demonstrating the promising prospect in separation technology and even widespread fields., (© 2022 Wiley-VCH GmbH.)

Herein, we report, for the first time, a unique stiffness-transformable manganese oxide hybridized mesoporous organosilica nanoplatform (MMON) for enhancing tumor therapeutic efficacy. The prepared MMONs had a quasi-spherical morphology and were completely transformed into soft bowl-like nanocapsules in the simulated tumor microenvironment through the breakage of Mn-O bonds, which decreased their Young's modulus from 165.7 to 84.5 MPa. Due to their unique stiffness transformation properties, the MMONs had reduced macrophage internalization, improved tumor cell uptake, and enhanced penetration of multicellular spheroids. In addition, in vivo experiments showed that the MMONs displayed a 3.79- and 2.90-fold decrease in non-specific liver distribution and a 2.87- and 1.83-fold increase in tumor accumulation compared to their soft and stiff counterparts, respectively. Furthermore, chlorin e6 (Ce6) modified MMONs had significantly improved photodynamic therapeutic effect., (© 2022 Wiley-VCH GmbH.)

Supported metal nanoparticles are used as heterogeneous catalysts but often deactivated due to sintering at high temperatures. Confining metal species into a porous matrix reduces sintering, yet supports rarely provide additional stabilization. Here, we used the silanol-rich layered zeolite IPC-1P to stabilize ultra-small Rh nanoparticles. By adjusting the IPC-1P interlayer space through swelling, we prepared various architectures, including microporous and disordered mesoporous. In situ scanning transmission electron microscopy confirmed that Rh nanoparticles are resistant to sintering at high temperature (750 °C, 6 hrs). Rh clusters strongly bind to surface silanol quadruplets at IPC-1P layers by hydrogen transfer to clusters, while high silanol density hinders their migration based on density functional theory calculations. Ultimately, combining swelling with long-chain surfactant and utilizing metal-silanol interactions resulted in a novel, catalytically active material-Rh@IPC&#95;C22., (© 2022 Wiley-VCH GmbH.)

With the emerging of the Internet of Things, chemiresistive gas sensors have been extensively applied in industrial production, food safety, medical diagnosis, and environment detection, etc. Considerable efforts have been devoted to improving the gas-sensing performance through tailoring the structure, functions, defects and electrical conductivity of sensitive materials. Among the numerous sensitive materials, mesoporous semiconductor metal oxides possess unparalleled properties, including tunable pore size, high specific surface area, abundant metal-oxygen bonds, and rapid mass transfer/diffusion behavior (Knudsen diffusion), which have been regarded as the most potential sensitive materials. Herein, the synthesis strategies for mesoporous metal oxides are overviewed, the classical functionalization techniques of sensitive materials are also systemically summarized as a highlight, including construction of mesoporous structure, regulation of micro-nano structure (i.e., heterojunctions), noble metal sensitization (e.g., Au, Pt, Ag, Pd) and heteroatomic doping (e.g., C, N, Si, S). In addition, the structure-function relationship of sensitive materials has been discussed at molecular-atomic level, especially for the chemical sensitization effect, elucidating the interface adsorption/catalytic mechanism. Moreover, the challenges and perspectives are proposed, which will open a new door for the development of intelligent gas sensor in various applications., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

A sulfhydryl monomicelles interfacial assembly strategy is presented for the synthesis of fully exposed single-atom-layer Pt clusters on 2D mesoporous TiO 2 (SAL-Pt@mTiO 2 ) nanosheets. This synthesis features the introduction of the sulfhydryl group in monomicelles to finely realize the controllable co-assembly process of Pt precursors within ordered mesostructures. The resultant SAL-Pt@mTiO 2 shows uniform SAL Pt clusters (≈1.2 nm) anchored in ultrathin 2D nanosheets (≈7 nm) with a high surface area (139 m 2  g -1 ), a large pore size (≈25 nm) and a high dispersion (≈99 %). Moreover, this strategy is universal for the synthesis of other SAL metal clusters (Pd and Au) on 2D mTiO 2 with high exposure and accessibility. When used as a catalyst for hydrogenation of 4-nitrostyrene, the SAL-Pt@mTiO 2 shows a high catalytic activity (TOF up to 2424 h -1 ), 100 % selectivity for 4-aminostyrene, good stability, and anti-resistance to thiourea poisoning under relatively mild conditions (25 °C, 10 bar)., (© 2022 Wiley-VCH GmbH.)

Mesoporous carbon microparticles (MCMPs) with anisotropic shapes and ordered structures are attractive materials that remain challenging to access. In this study, a facile yet versatile route is developed to prepare anisotropic MCMPs by combining neutral interface-guided 3D confined self-assembly (3D-CSA) of block copolymer (BCP) with a self-templated direct carbonization strategy. This route enables pre-engineering BCP into microparticles with oblate shape and hexagonal packing cylindrical mesostructures, followed by selective crosslinking and decorating of their continuous phase with functional species (such as platinum nanoparticles, Pt NPs) via in situ growth. To realize uniform in situ growth, a "guest exchange" strategy is proposed to make room for functional species and a pre-crosslinking strategy is developed to preserve the structural stability of preformed BCP microparticles during infiltration. Finally, Pt NP-loaded MCMPs are derived from the continuous phase of BCP microparticles through selective self-templated direct carbonization without using any external carbon source. This study introduces an effective concept to obtain functional species-loaded and N-doped MCMPs with oblate shape and almost hexagonal structure (p6mm), which would find important applications in fuel cells, separation, and heterogeneous catalysis., (© 2022 The Authors. Advanced Science published by Wiley-VCH GmbH.)

Microbial cell factories reinvigorate current industries by producing complex fine chemicals at low costs. Reduced nicotinamide adenine dinucleotide phosphate (NADPH) is the main reducing power to drive the biosynthetic pathways in microorganisms. However, insufficient intrinsic NADPH limits the productivity of microorganisms. Here, we report that supplying microorganisms with long-lived electrons from persistent phosphor mesoporous Al 2 O 3 (meso-Al 2 O 3 ) can elevate the NADPH level to facilitate efficient fine chemical production. The defects in meso-Al 2 O 3 were demonstrated to be highly efficient in prolonging electrons' lifetime. The long-lived electrons in meso-Al 2 O 3 can pass the material-microorganism interface and power the biosynthetic pathways of E. coli to produce jet fuel farnesene. This work represents a reliable strategy to design photo-biosynthesis systems to improve the productivity of microorganisms with solar energy., (© 2022 Wiley-VCH GmbH.)

Nanovaccine-based immunotherapy (NBI) has the ability to initiate dendritic cell (DC)-mediated tumor-specific immune responses and maintain long-term antitumor immune memory. To date, the mechanism by which the mechanical properties of nanoparticles alter the functions of DCs in NBI remains largely unclear. Here, a soft mesoporous organosilica-based nanovaccine (SMONV) is prepared and the elasticity-dependent effect of the nanovaccine on the underlying DC-mediated immune responses is studied. It is found that the elasticity results in greater internalization of SMONV by DCs, followed by the induction of substantial cytosolic delivery of antigens via endosomal escape, leading to effective DC maturation and antigen cross-presentation. Impressively, elasticity enables SMONV to enhance lymphatic drainage of antigens in vivo, thus stimulating robust humoral and cellular immunity. The results from therapeutic tumor vaccination further reveal that subcutaneously administered SMONV effectively suppresses tumor growth in tumor-bearing mice by evoking antigen-specific CD8 + T-cell immune responses, mitigating regulatory T-cell-mediated immunosuppression, and increasing central memory and effector memory T-cell populations. Furthermore, combinatorial immunization with SMONV and anti-PD-L1 blocking antibodies results in an amplified therapeutic effect on tumor-bearing mice. These findings reveal the elastic effect of the nanovaccine on DC-mediated immune responses, and the prepared SMONV represents a facile and powerful strategy for antitumor immunotherapy., (© 2022 The Authors. Small published by Wiley-VCH GmbH.)

Sodium-ion batteries (SIBs) are a promising candidate for grid-scale energy storage, however, the sluggish ion-diffusion kinetics brought by the large radius of Na + seriously limits the performance of SIBs, let alone at low temperatures. Herein, a confined acid-base pair self-assembly strategy to synthesize unusual Ti 0.88 Nb 0.88 O 4- x @C for high-performance SIBs operating at room and low temperatures is proposed. The confinement self-assembly of the acid-base pair around the micelles and confined crystallization by the carbon layer realize the formation of ordered and stoichiometric mesoporous frameworks with opened ion channels. Thus, the mesoporous Ti 0.88 Nb 0.88 O 4- x @C exhibits rapid Na + diffusion kinetics at 25 and -40 °C, which are one order higher than that of the nonporous one. A high reversible capacity of 233 mAh g -1 , excellent rate (a specific capacity of 103 mAh g -1 at 50 C), and cycling performances (<0.03% fading per cycle) can be observed at 25 °C. More importantly, even at -40 °C, the mesoporous Ti 0.88 Nb 0.88 O 4- x @C can still deliver the 161 mAh g -1 capacity, a high initial Coulombic efficiency of 60% and outstanding cycling stability (99 mAh g -1 at 0.5 C after 500 cycles). It is believed this strategy opens a new avenue for constructing novel mesoporous electrode materials for low-temperature energy storage., (© 2022 Wiley-VCH GmbH.)

The design of porous noble metal catalysts holds great promise in various electrocatalytic applications. However, it is still a challenge to improve the durability performance through constructing stable framework. Here, an interface and charge induced strategy is developed to synthesize large-sized continuous reduced graphene oxide@mesoporous platinum (denoted as rGO@mPt) sheets under kinetic control by molecular self-assembly design. Graphene oxide (GO) is a promising large-sized growth interface for platinum. Cationic surfactant dioctadecyldimethylammonium chloride bridges the negatively charged GO and platinum precursors, while creating interconnected mesopores. The successful synthesis of rGO@mPt sheets relies on proper kinetic control, which is achieved by controlling pH, temperature, and the complexation of bromide ions. rGO@mPt sheets present strong crystallinity with a pure face-centered cubic Pt phase. Worm-like mesostructures with an average pore size of 2.2 nm exist throughout the sheets. rGO@mPt sheets possess both stable framework and abundant active sites, which markedly improve the durability on methanol oxidation reaction while maintaining relatively good catalytic activity. Long-term stability test shows a slight loss of 1.2% activity after 250 cycles. Amperometric i-t curves reveal the mass current three times higher compared to commercial Pt/C at 3000 s., (© 2022 Wiley-VCH GmbH.)

In this paper, a simple approach, using interfacial self-assembly of block copolymers (BCPs) on self-sacrificial templates, for preparing mesoporous carbons with in-plane holey pores, including nitrogen atom-doped carbon nanosheets and nanoflowers (denoted as NHCSs and NHCFs), is reported. The approach employs sheet- or flower-like layered double hydroxide as the templates, P123 copolymer as the pore-directing agent, and m-phenylenediamine as the carbon source. The holey mesopores may shorten the mass transfer distance in the internal active sites of stacked nanosheets, while the 3D packing mode of nanosheets can reduce pore blockage caused by their tight stacking. Profiting from these structural advantages, acting as electrocatalysts for oxygen reduction reaction (ORR), both NHCSs and NHCFs show excellent catalytic performance better than that of carbon nanosheets without holey pores. Particularly, NHCFs exhibit a high half-wave-potential (0.82 V) and a limiting current density (5.4 mA cm -2 ), close to those of commercial Pt-C catalysts. This study provides valuable clues on building mesoporous materials with in-plane holey pores as well as on the effect of pore structure and stacking mode of 2D materials on their electrocatalytic ORR performance., (© 2022 Wiley-VCH GmbH.)