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Abstract Rational design of robust photocatalytic systems to direct capture and in-situ convert diluted CO2 from flue gas is a promising but challenging way to achieve carbon neutrality. Here, we report a new type of host-guest photocatalysts by integrating CO2-enriching ionic liquids and photoactive metal-organic frameworks PCN-250-Fe2M (M = Fe, Co, Ni, Zn, Mn) for artificial photosynthetic diluted CO2 reduction in gas-solid phase. As a result, [Emim]BF4(39.3 wt%)@PCN-250-Fe2Co exhibits a record high CO2-to-CO reduction rate of 313.34 μmol g−1 h−1 under pure CO2 atmosphere and 153.42 μmol g−1 h−1 under diluted CO2 (15%) with about 100% selectivity. In scaled-up experiments with 1.0 g catalyst and natural sunlight irradiation, the concentration of pure and diluted CO2 (15%) could be significantly decreased to below 85% and 10%, respectively, indicating its industrial application potential. Further experiments and theoretical calculations reveal that ionic liquids not only benefit CO2 enrichment, but also form synergistic effect with Co2+ sites in PCN-250-Fe2Co, resulting in a significant reduction in Gibbs energy barrier during the rate-determining step of CO2-to-CO conversion.

Abstract Ultra-low temperature resistant adhesive is highly desired yet scarce for material adhesion for the potential usage in Arctic/Antarctic or outer space exploration. Here we develop a solvent-free processed low-temperature tolerant adhesive with excellent adhesion strength and organic solvent stability, wide tolerable temperature range (i.e. −196 to 55 °C), long-lasting adhesion effect ( > 60 days, −196 °C) that exceeds the classic commercial hot melt adhesives. Furthermore, combine experimental results with theoretical calculations, the strong interaction energy between polyoxometalate and polymer is the main factor for the low-temperature tolerant adhesive, possessing enhanced cohesion strength, suppressed polymer crystallization and volumetric contraction. Notably, manufacturing at scale can be easily achieved by the facile scale-up solvent-free processing, showing much potential towards practical application in Arctic/Antarctic or planetary exploration.

Abstract Nanofluidic membranes have demonstrated great potential in harvesting osmotic energy. However, the output power densities are usually hampered by insufficient membrane permselectivity. Herein, we design a polyoxometalates (POMs)-based nanofluidic plasmonic electron sponge membrane (PESM) for highly efficient osmotic energy conversion. Under light irradiation, hot electrons are generated on Au NPs surface and then transferred and stored in POMs electron sponges, while hot holes are consumed by water. The stored hot electrons in POMs increase the charge density and hydrophilicity of PESM, resulting in significantly improved permselectivity for high-performance osmotic energy conversion. In addition, the unique ionic current rectification (ICR) property of the prepared nanofluidic PESM inhibits ion concentration polarization effectively, which could further improve its permselectivity. Under light with 500-fold NaCl gradient, the maximum output power density of the prepared PESM reaches 70.4 W m−2, which is further enhanced even to 102.1 W m−2 by changing the ligand to P5W30. This work highlights the crucial roles of plasmonic electron sponge for tailoring the surface charge, modulating ion transport dynamics, and improving the performance of nanofluidic osmotic energy conversion.

Abstract The conversion of the biomass into eco‐friendly fuels and chemicals has been extensively recognized as the essential pathway to achieve the sustainable economy and carbon neutral society. Lignin, as a kind of promising biomass energy, has been certified to produce the high‐valued chemicals and fuels. Numerous efforts have been made to develop various catalysts for lignin catalytic conversion. Both metal‐organic frameworks (MOFs) and covalent organic frameworks (COFs) belong to very important heterogeneous porous catalysts due to their regular porous structures, high specific surface area, and precisely tailored diversities. In the review, the first part focused on the catalytic conversion of lignin, lignin model compounds, and lignin derivatives using the pristine MOFs, functional MOF composites, and MOF‐derived materials. The second part summarized the catalytic conversion of lignin model compounds using pristine COFs and functional COF composites. The review here mainly concentrated on the design of the materials, screening of catalytic conditions, and explorations of the corresponded mechanisms. Specifically, (1) we summarized the MOF‐ and COF‐based materials for the effects on the catalytic transformation of lignin‐related substances; (2) we emphasized the catalytic mechanism of C–C and C–O bonds cleavage together with the structure–activity relationships; (3) we in‐depth realized the relationship between the chemical/electronic/structural properties of the MOF‐ and COF‐based catalysts and their catalytic performance for lignin‐related substances. Finally, the challenges and future perspectives were also discussed on the catalytic conversion of lignin‐related substances by MOF‐ and COF‐based catalysts.

Abstract In modern industries, the aerobic oxidation of C(sp3)-H bonds to achieve the value-added conversion of hydrocarbons requires high temperatures and pressures, which significantly increases energy consumption and capital investment. The development of a light-driven strategy, even under natural sunlight and ambient air, is therefore of great significance. Here we develop a series of hetero-motif molecular junction photocatalysts containing two bifunctional motifs. With these materials, the reduction of O2 and oxidation of C(sp3)-H bonds can be effectively accomplished, thus realizing efficient aerobic oxidation of C(sp3)-H bonds in e.g., toluene and ethylbenzene. Especially for ethylbenzene oxidation reactions, excellent catalytic capacity (861 mmol g cat−1) is observed. In addition to the direct oxidation of C(sp3)-H bonds, CeBTTD-A can also be applied to other types of aerobic oxidation reactions highlighting their potential for industrial applications.

Abstract The semi‐hydrogenation of alkyne to form Z‐olefins with high conversion and high selectivity is still a huge challenge in the chemical industry. Moreover, flammable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial production. Herein, we connect the photocatalytic hydrogen evolution reaction and the semi‐hydrogenation reaction of alkynes in series and successfully realize the high selective production of Z‐alkenes using low‐cost, safe, and green water as the proton source. Before the cascade reaction, a series of isomorphic metal–organic cage catalysts (CoxZn8−xL6, x = 0, 3, 4, 5, and 8) are designed and synthesized to improve the yield of the photocatalytic hydrogen production. Among them, Co5Zn3L6 shows the highest photocatalytic activity, with a H2 generation rate of 8.81 mmol g−1 h−1. Then, Co5Zn3L6 is further applied in the above tandem reaction to efficiently reduce alkynes to Z‐alkenes under ambient conditions, which can reach high conversion of >98% and high selectivity of >99%, and maintain original catalytic activity after multiple cycles. This “one‐pot” tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z‐olefins under mild reaction conditions.

A well-defined catalyst with dual Ni/Fe atomic active sites was created using a pyrolysis-free approach. The as-made catalyst was used for overall electrochemical water splitting in both acidic and alkaline electrolytes with low overpotentials.

Owing to the high storage capacity and multiple‐electron‐transfer chemistry of sulfur (S), sulfur‐based (S‐based) batteries with merits of high theoretical capacity/energy density, eco‐friendliness, and abundant supply hold much potential for energy‐storage/conversion devices. The capacity of S‐based batteries is much higher than that of traditional‐metal‐oxide cathode‐based lithium‐ion batteries, which is regarded as the highest capacity of solid‐state cathode materials at the current stage. As a vital component of S‐based batteries, separators play a profound role in resolving urgent issues (e.g., shuttling effect, volume expansion, poor conductivity, and metal dendrites, etc.). So far, some pioneering works have been reported in the exploration of separators for S‐based battery. On this basis, covalent organic frameworks (COFs), as a kind of functional materials, offer much possibility for S‐based battery separators due to their advantages such as high porosity, crystalline and well‐defined structures, designable struts, and tunable functions, etc. Herein, the reported works about COFs in S‐based battery separators including their structural characteristics, preparation methods, application forms, and battery properties are summarized. Moreover, also, a brief perspective is proposed on the challenges of COFs applied in S‐based battery separators, and new insights are provided for scientists in this field.

Covalent organic frameworks (COFs) are an emerging type of crystalline and porous photocatalysts for hydrogen evolution. Here, the authors report a β-ketoamine COF by systematically engineering N-sites, architecture, and morphology for improved water splitting activity.

Abstract The efficient CO2 electroreduction into high‐value products largely relies on the CO2 adsorption/activation or electron‐transfer of electrocatalysts, thus site‐specific functionalization methods that enable boosted related interactions of electrocatalysts are much desired. Here, an oriented coordination strategy is reported to introduce N‐rich auxiliary (i.e., hexamethylenetetramine, HMTA) into metalloporphyrin metal organic frameworks (MOFs) to synthesize a series of site‐specific functionalized electrocatalysts (HMTA@MOF‐545‐M, M = Fe, Co, and Ni) and they are successfully applied in light‐assisted CO2 electroreduction. Noteworthy, thus‐obtained HMTA@MOF‐545‐Co presents approximately two times enhanced CO2 adsorption‐enthalpy and electrochemical active surface‐area with largely decreased impedance‐value after modification, resulting in almost twice higher CO2 electroreduction performance than its unmodified counterpart. Besides, its CO2 electroreduction performance can be further improved under light‐illumination and displays superior FECO (≈100%), high CO generation rate (≈5.11 mol m−2 h−1 at −1.1 V) and energy efficiency (≈70% at −0.7 V). Theoretical calculations verify that the oriented coordination of HMTA can increase the charge density of active sites, almost doubly enhance the CO2 adsorption energy, and largely reduce the energy barrier of rate determining step for the boosted performance improvement. This work might promote the development of modifiable porous crystalline electrocatalysts in high‐efficiency CO2 electroreduction.

Electrocatalytic CO2 reduction (ECR) to high value-added chemicals by using renewable electricity presents a promising strategy to realize “carbon neutrality”. However, the ECR system is still limited by its low current density and poor CO2 utilization efficiency. Herein, by using the confinement effect of covalent organic frameworks (COFs) to confine the in-situ growth of metal nanoclusters (NCs), we develop a series of Cu NCs encapsulated on COF catalysts (Cu-NC@COF) for ECR. Among them, Cu-NC@CuPc-COF as a gas diffusion electrode (GDE) achieves a maximum CO2-to-CH4 Faradaic efficiency of 74 ​± ​3% (at −1.0 ​V vs. Reversible Hydrogen Electrode (RHE)) with a current density of 538 ​± ​31 ​mA ​cm−2 (at −1.2 ​V vs. RHE) in a flow cell, making it one of the best among reported materials. More importantly, the current density is much higher than the relevant industrial current density (200 ​mA ​cm−2), indicating the potential for industrial application. This work opens up new possibilities for the design of ECR catalysts that utilize synergistic strategy.

A crystalline hetero-metallic cluster catalyst based on a covalent organic framework strategy is reported. The catalyst can facilitate both photocatalytic oxidative and reductive reactions leading to efficient production of HCOOH from CO2 and H2O.

A Ni-based MOF catalyst is reported to facilitate the photocatalytic reduction of CO2 to CO, a low-value product. In tandem, the as-produced CO is used as a reactant in the Pd-catalyzed carbonylation of aryl halides and other fine organic chemicals.

Crystalline porous catalysts with single Cu sites are dedicated to exploring the dependence of CO2 electroreduction selectivity on the coordination environment of catalytic sites. The conductive MOF Cu-DBC with oxygen-coordinated Cu sites shows a high Faradaic efficiency ~80% of CO2-to-CH4.

The study of covalent organic frameworks (COFs) in electrocatalytic CO2 reduction reaction (CO2RR) has drawn much attention. Here the authors show a series of tetrathiafulvalene based COFs designed and exfoliated into nanosheets which exhibit high electrocatalytic CO2RR performance.

Engineering the heterogeneous interface fusing MOFs and inorganic active component is an effective strategy to improve the electrochemical performance. Herein, we report a new Ni3-based MOF (denoted as CTGU-24) with an infrequent two-fold interpenetrating 3D (3,8)-connected network constructed from Ni(II) trimer and mixed tripodal tectonics for the electrocatalytic methanol oxidation reaction (MOR). In order to improve its stability and activities, the heterogeneous hybrid CTGU-24@NiOOH has been fabricated successfully via the first preparation of the NiOOH nanosphere and then in situ formation of CTGU-24 decorated on the NiOOH surface. Moreover, the integration of CTGU-24@NiOOH and different additives [acetylene black (AB) and ketjen black (KB)], resulting in the optimized hybrid sample AB&CTGU-24@NiOOH (4:4). It attains better MOR performance with an area-specific peak current density of 34.53 mA·cm−2 than pure CTGU-24 (14.99 mA·cm−2) and improved durability in an alkali medium. The new findings indicate that the CTGU-24@NiOOH heterostructure formed in situ and the integration of moderate additives are critical to optimizing and improving electrocatalytic activity of pure MOF crystalline material.

Metal–organic frameworks (MOFs), constructed from metal clusters/ions and organic ligands, are ideal materials for photo/electrocatalysis, mainly due to the advantages of large surface areas, high porosity, and easily tunable optical and electronic structures. Herein, the recent and important advances on MOF‐based photo/electrocatalysts including pristine MOFs, MOF composites, and MOF derivatives are summarized. The novel strategies to improve the photo/electrocatalytic performances are highlighted. Finally, the current challenges and future development of MOFs for photo/electrocatalysis are discussed ad outlined.

While CO2 reduction provides a way to remove carbon from the atmosphere, it is challenging to design effective, selective materials for this process. Here, authors construct metal-organic frameworks from polyoxometalates and porphryins to direct electron flow and improve CO2 reduction efficiencies.

The development of low-cost and earth-abundant non-noble-metal catalysts for the hydrogen evolution reaction remains a challenge. Here, the authors report and evaluate a catalyst based on a two-dimensional coupled hybrid of molybdenum carbide and reduced graphene oxide.