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Precise design and tuning of Zn hopping/transfer sites with deeper understanding of the dendrite‐formation mechanism is vital in artificial anode protective coating for aqueous Zn‐ion batteries (AZIBs). Here, we probe into the role of anode‐coating interfaces by designing a series of anhydride‐based covalent organic frameworks (i.e. PI‐DP‐COF and PI‐DT‐COF) with specifically designed zigzag hopping sites and zincophilic anhydride groups that can serve as desired platforms to investigate the related Zn2+ hopping/transfer behaviours as well as the interfacial interaction. Combining theoretical calculations with experiments, the ABC stacking models of these COFs endow the structures with specific zigzag sites along the 1D channel that can accelerate Zn2+ transfer kinetics, lower surface‐energy, homogenize ion‐distribution or electric‐filed. Attributed to these superiorities, thus‐obtained optimal PI‐DT‐COF cells offer excellent cycling lifespan in both symmetric‐cell (2000 cycles at 60 mA cm−2) and full‐cell (1600 cycles at 2 A g−1), outperforming almost all the reported porous crystalline materials. [ABSTRACT FROM AUTHOR]

Visible‐light sensitive and bi‐functionally favored CO2 reduction (CRR)/evolution (CER) photocathode catalysts that can get rid of the utilization of ultraviolet light and improve sluggish kinetics is demanded to conquer the current technique‐barrier of traditional Li‐CO2 battery. Here, a kind of redox molecular junction sp2c metal‐covalent organic framework (i.e. Cu3‐BTDE‐COF) has been prepared through the connection between Cu3 and BTDE and can serve as efficient photocathode catalyst in light‐assisted Li‐CO2 battery. Cu3‐BTDE‐COF with redox‐ability, visible‐light‐adsorption region, electron‐hole separation ability and endows the photocathode with excellent round‐trip efficiency (95.2 %) and an ultralow voltage hysteresis (0.18 V), outperforming the Schiff base COFs (i.e. Cu3‐BTDA‐COF and Cu3‐DT‐COF) and majority of the reported photocathode catalysts. Combined theoretical calculations with characterizations, Cu3‐BTDE‐COF with the integration of Cu3 centers, thiazole and cyano groups possess strong CO2 adsorption/activation and Li+ interaction/diffusion ability to boost the CRR/CER kinetics and related battery property. [ABSTRACT FROM AUTHOR]

The high local electron density and efficient charge carrier separation are two important factors to affect photocatalytic activity, especially for the CO2 photoreduction reaction. However, the systematic studies on the structure‐functional relationship regarding the above two factors based on precisely structure model are rarely reported. Herein, as a proof‐of‐concept, we developed a new strategy on the evaluation of local electron density by controlling the relative electron‐deficient (ED) and electron‐rich (ER) intensity of monomer at a molecular level based on three rational‐designed vinylene‐linked sp2 carbon‐covalent organic frameworks (COFs). As expected, the as‐prepared vinylene‐linked sp2 carbon‐conjugated metal‐covalent organic framework (MCOFs) (VL‐MCOF‐1) with molecular junction exhibited excellent activities for CO2‐to‐HCOOH conversion (283.41 μmol g−1 h−1) and high selectivity of 97.1 %, much higher than the VL‐MCOF‐2 and g‐C34N6‐COF, which is due to the synergistic effect of the multi‐electronic metal clusters (Cu3(PyCA)3) (PyCA=pyrazolate‐4‐carboxaldehyde) as strong ER roles and cyanopyridine units as ED roles and active sites, as well as the boosted photo‐induced charge separation efficiency of vinyl connection and increased light utilization ability. These results not only provide a strategy for regulating the electron‐density distribution of photocatalysts at the molecular level but also offers profound insights for metal clusters‐based COFs to effective CO2 conversion. [ABSTRACT FROM AUTHOR]

Structural variants of high‐nuclearity clusters are extremely important for their modular assembly study and functional expansion, yet the synthesis of such giant structural variants remains a great challenge. Herein, we prepared a lantern‐type giant polymolybdate cluster (L‐Mo132) containing equal metal nuclearity with the famous Keplerate type Mo132 (K‐Mo132). The skeleton of L‐Mo132 features a rare truncated rhombic triacontrahedron, which is totally different with the truncated icosahedral K‐Mo132. To the best of our knowledge, this is the first time to observe such structural variants in high‐nuclearity cluster built up of more than 100 metal atoms. Scanning transmission electron microscopy reveals that L‐Mo132 has good stability. More importantly, because the pentagonal [Mo6O27]n− building blocks in L‐Mo132 are concave instead of convex in the outer face, it contains multiple terminal coordinated water molecules on its outer surface, which make it expose more active metal sites to display superior phenol oxidation performance, which is more higher than that of K‐Mo132 coordinated in M=O bonds on the outer surface. [ABSTRACT FROM AUTHOR]

H2O2 photosynthesis coupled with biomass valorization can not only maximize the energy utilization but also realize the production of value‐added products. Here, a series of COFs (i.e. Cu3‐BT‐COF, Cu3‐pT‐COF and TFP‐BT‐COF) with regulated redox molecular junctions have been prepared to study H2O2 photosynthesis coupled with furfuryl alcohol (FFA) photo‐oxidation to furoic acid (FA). The FA generation efficiency of Cu3‐BT‐COF was found to be 575 mM g−1 (conversion ≈100 % and selectivity >99 %) and the H2O2 production rate can reach up to 187 000 μM g−1, which is much higher than Cu3‐pT‐COF, TFP‐BT‐COF and its monomers. As shown by theoretical calculations, the covalent coupling of the Cu cluster and the thiazole group can promote charge transfer, substrate activation and FFA dehydrogenation, thus boosting both the kinetics of H2O2 production and FFA photo‐oxidation to increase the efficiency. This is the first report about COFs for H2O2 photosynthesis coupled with biomass valorization, which might facilitate the exploration of porous‐crystalline catalysts in this field. [ABSTRACT FROM AUTHOR]

The full reaction photosynthesis of H2O2 that can combine water‐oxidation and oxygen‐reduction without sacrificial agents is highly demanded to maximize the light‐utilization and overcome the complex reaction‐process of anthraquinone‐oxidation. Here, a kind of oxidation‐reduction molecular junction covalent‐organic‐framework (TTF‐BT‐COF) has been synthesized through the covalent‐coupling of tetrathiafulvalene (photo‐oxidation site) and benzothiazole (photo‐reduction site), which presents visible‐light‐adsorption region, effective electron‐hole separation‐efficiency and photo‐redox sites that enables full reaction generation of H2O2. Specifically, a record‐high yield (TTF‐BT‐COF, ≈276 000 μM h−1 g−1) for H2O2 photosynthesis without sacrificial agents has been achieved among porous crystalline photocatalysts. This is the first work that can design oxidation‐reduction molecular junction COFs for full reaction photosynthesis of H2O2, which might extend the scope of COFs in H2O2 production. [ABSTRACT FROM AUTHOR]

Strategy that can design powerful photothermal‐catalysts to achieve photothermal‐effect assisted coupling‐catalysis is much desired for the improvement of energy conversion efficiency and redox product value in CO2 electroreduction system. Herein, a kind of bifunctional viologen‐containing covalent organic framework (Ni‐2CBpy2+‐COF) has been prepared and successfully applied in photothermal‐assisted co‐electrolysis of CO2 and methanol. Specifically, the FECO (cathode) and FEHCOOH (anode) for Ni‐2CBpy2+‐COF can reach up to ≈100 % at 1.9 V with ≈31.5 % saved overall electricity‐consumption when the anodic oxygen evolution reaction (OER) is replaced by methanol oxidation. The superior performance could be attributed to the cyclic diquats in Ni‐2CBpy2+‐COF that enhance the photothermal effect (ΔT=49.1 °C) to accelerate faster charge transfer between catalyst and immediate species as well as higher selectivity towards desired products as revealed by DFT calculations and characterizations. [ABSTRACT FROM AUTHOR]

As hot topics in the chemical conversion of CO2, the photo‐/electrocatalytic reduction of CO2 and use of CO2 as a supporter for energy storage have shown great potential for the utilization of CO2. However, many obstacles still exist on the road to realizing highly efficient chemical CO2 conversion, such as inefficient uptake/activation of CO2 and mass transport in catalysts. Covalent organic frameworks (COFs), as a kind of porous material, have been widely explored as catalysts for the chemical conversion of CO2 owing to their unique features. In particular, COF‐based functional materials containing diverse active sites (such as single metal sites, metal nanoparticles, and metal oxides) offer great potential for realizing CO2 conversion and energy storage. This Minireview discusses recent breakthroughs in the basic knowledge, mechanisms, and pathways of chemical CO2 conversion strategies that use COF‐based functional catalysts. In addition, the challenges and prospects of COF‐based functional catalysts for the efficient utilization of CO2 are also introduced. [ABSTRACT FROM AUTHOR]

Strategies that enable simultaneous morphology‐tuning and electroreduction performance boosting are much desired for the exploration of covalent organic frameworks in efficient CO2 electroreduction. Herein, a kind of functionalizing exfoliation agent has been selected to simultaneously modify and exfoliate bulk COFs into functional nanosheets and investigate their CO2 electroreduction performance. The obtained nanosheets (Cu−Tph−COF−Dct) with large‐scale (≈1.0 μm) and ultrathin (≈3.8 nm) morphology enable a superior FECH4 (≈80 %) (almost doubly enhanced than bare COF) with large current‐density (−220.0 mA cm−2) at −0.9 V. The boosted performance can be ascribed to the immobilized functionalizing exfoliation agent (Dct groups) with integrated amino and triazine groups that strengthen CO2 absorption/activation, stabilize intermediates and enrich the CO concentration around the Cu active sites as revealed by DFT calculations. The point‐to‐point functionalization strategy for modularly assembling Dct‐functionalized COF catalyst for CO2 electroreduction will open up the attractive possibility of developing COFs as efficient CO2RR electrocatalysts. [ABSTRACT FROM AUTHOR]

The exploration of new application forms of covalent organic frameworks (COFs) in Li−S batteries that can overcome drawbacks like low conductivity or high loading when typically applied as sulfur host materials (mostly ≈20 to ≈40 wt % loading in cathode) is desirable to maximize their low‐density advantage to obtain lightweight, portable, or high‐energy‐density devices. Here, we establish that COFs could have implications as microadditives of binders (≈1 wt % in cathode), and a series of anthraquinone‐COF based hollow tubes have been prepared as model microadditives. The microadditives can strengthen the basic properties of the binder and spontaneously immobilize and catalytically convert lithium polysulfides, as proved by density functional calculations, thus showing almost doubly enhanced reversible capacity compared with that of the bare electrode. [ABSTRACT FROM AUTHOR]

Purposefully designing the well‐defined catalysts for the selective electroreduction of CO2 to C2H4 is an extremely important but challenging work. In this work, three crystalline trinuclear copper clusters (Cu3‐X, X=Cl−, Br−, NO3−) have been designed, containing three active Cu sites with the identical coordination environment and appropriate spatial distance, delivering high selectivity for the electrocatalytic reduction of CO2 to C2H4. The highest faradaic efficiency of Cu3‐X for CO2‐to‐C2H4 conversion can be adjusted from 31.90 % to 55.01 % by simply replacing the counter anions (NO3−, Cl−, Br−). The DFT calculation results verify that Cu3‐X can facilitate the C−C coupling of identical *CHO intermediates, subsequently forming molecular symmetrical C2H4 product. This work provides an important molecular model system and a new design perspective for electroreduction of CO2 to C2 products with symmetrical molecular structure. [ABSTRACT FROM AUTHOR]

The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well‐designed electrocatalysts with advantages like proton generation/transferring and intermediate‐fixating for efficient CO2RR are much preferred yet largely unexplored. In this work, a kind of Cu‐porphyrin‐based large‐scale (≈1.5 μm) and ultrathin nanosheet (≈5 nm) has been successfully applied in electrochemical CO2RR. It exhibits a superior FECH4 of 70 % with a high current density (−183.0 mA cm−2) at −1.6 V under rarely reported neutral conditions and maintains FECH4 >51 % over a wide potential range (−1.5 to −1.7 V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen‐bonding networks through the integration of diaminotriazine with Cu‐porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen‐bonding‐based materials as efficient CO2RR catalysts. [ABSTRACT FROM AUTHOR]

In the electrochemical CO2 reduction reaction (CO2RR), it is challenging to develop a stable, well‐defined catalyst model system that is able to examine the influence of the synergistic effect between adjacent catalytic active sites on the selective generation of C1 or C2 products. We have designed and synthesized a stable crystalline single‐chain catalyst model system for electrochemical CO2RR, which involves four homomorphic one‐dimensional chain‐like compounds (Cu‐PzH, Cu‐PzCl, Cu‐PzBr, and Cu‐PzI). The main structural difference of these four chains is the substituents of halogen atoms with different electronegativity on the Pz ligands. Consequently, different synergistic effects between bi‐copper centers lead to changes in the faradic efficiency (FECH4 :FEC2H4). This work provides a simple and stable crystalline single‐chain model system for systematically studying the influence of coordination microenvironment on catalytically active centers in the CO2RR. [ABSTRACT FROM AUTHOR]

In this work, we rationally designed a series of crystalline and stable dioxin‐linked metallophthalocyanine covalent organic frameworks (COFs; MPc‐TFPN COF, M=Ni, Co, Zn) under the guidance of reticular chemistry. As a novel single‐site catalysts (SSCs), NiPc/CoPc‐TFPN COF exhibited outstanding activity and selectivity for electrocatalytic CO2 reduction (ECR; Faradaic efficiency of CO (FECO)=99.8(±1.24) %/ 96.1(±1.25) % for NiPc/CoPc‐TFPN COF). More importantly, when coupled with light, the FECO and current density (jCO) were further improved across the applied potential range (−0.6 to −1.2 V vs. RHE) compared to the dark environment for NiPc‐TFPN COF (jCO increased from 14.1 to 17.5 A g−1 at −0.9 V; FECO reached up to ca. 100 % at −0.8 to −0.9 V). Furthermore, an in‐depth mechanism study was established by density functional theory (DFT) simulation and experimental characterization. For the first time, this work explored the application of COFs as photo‐coupled electrocatalysts to improve ECR efficiency, which showed the potential of using light‐sensitive COFs in the field of electrocatalysis. [ABSTRACT FROM AUTHOR]

The design of efficient heterogeneous redox mediators with favorable affinity to substrate and electrolyte are much desired yet still challenging for the development of indirect electrolysis system. Herein, for the first time, we have developed a solid–liquid–gas three‐phase indirect electrolysis system based on a covalent organic framework (Dha−COF−Cu) as heterogeneous redox mediator for S−S coupling reaction. Dha−COF−Cu with the integration of high porosity, nanorod morphology, abundant hydroxyl groups and active Cu sites is much beneficial for the adsorption/activation of thiols, uniform dispersion and high wettability in electrolyte, and efficient interfacial electron transfer. Notably, Dha−COF−Cu as solid‐phase redox mediator exhibits excellent electrocatalytic efficiency for the formation of value‐added liquid‐phase S−S bond product (yields up to 99 %) coupling with the generation of gas‐phase product of H2 (~1.40 mmol g−1 h−1), resulting in a powerful three‐phase indirect electrolysis system. This is the first work about COFs that can be applied in three‐phase indirect electrolysis system, which might promote the development of porous crystalline materials in this field. [ABSTRACT FROM AUTHOR]

The full reaction photosynthesis of H2O2 that can combine water‐oxidation and oxygen‐reduction without sacrificial agents is highly demanded to maximize the light‐utilization and overcome the complex reaction‐process of anthraquinone‐oxidation. Here, a kind of oxidation‐reduction molecular junction covalent‐organic‐framework (TTF‐BT‐COF) has been synthesized through the covalent‐coupling of tetrathiafulvalene (photo‐oxidation site) and benzothiazole (photo‐reduction site), which presents visible‐light‐adsorption region, effective electron‐hole separation‐efficiency and photo‐redox sites that enables full reaction generation of H2O2. Specifically, a record‐high yield (TTF‐BT‐COF, ≈276 000 μM h−1 g−1) for H2O2 photosynthesis without sacrificial agents has been achieved among porous crystalline photocatalysts. This is the first work that can design oxidation‐reduction molecular junction COFs for full reaction photosynthesis of H2O2, which might extend the scope of COFs in H2O2 production. [ABSTRACT FROM AUTHOR]

The exploration of novel systems for the electrochemical CO2 reduction reaction (CO2RR) for the production of hydrocarbons like CH4 remains a giant challenge. Well‐designed electrocatalysts with advantages like proton generation/transferring and intermediate‐fixating for efficient CO2RR are much preferred yet largely unexplored. In this work, a kind of Cu‐porphyrin‐based large‐scale (≈1.5 μm) and ultrathin nanosheet (≈5 nm) has been successfully applied in electrochemical CO2RR. It exhibits a superior FECH4 of 70 % with a high current density (−183.0 mA cm−2) at −1.6 V under rarely reported neutral conditions and maintains FECH4 >51 % over a wide potential range (−1.5 to −1.7 V) in a flow cell. The high performance can be attributed to the construction of numerous hydrogen‐bonding networks through the integration of diaminotriazine with Cu‐porphyrin, which is beneficial for proton migration and intermediate stabilization, as supported by DFT calculations. This work paves a new way in exploring hydrogen‐bonding‐based materials as efficient CO2RR catalysts. [ABSTRACT FROM AUTHOR]