Xingwang Lan

The photoreduction of CO ₂ into multi‐carbon (C ₂₊ ) products is a highly attractive route for CO ₂ utilization; however, the yield and selectivity of C ₂₊ products are seriously limited by slow multi‐electron–proton transfer and sluggish C─C coupling kinetics. Herein, we construct a hierarchical tandem photocatalyst IS@COF‐Ni by growing imine‐pyridine covalent organic frameworks on non‐stoichiometric indium sulfide and introducing isolated Ni single‐atom sites at the interfacial edges. The synergistic effect between the spatially segregated sites promotes *CO dimerization, effectively lowering the kinetic barrier for high‐rate ethylene (C ₂ H ₄ ) generation. Thus, compared with its individual components, the IS@COF‐Ni heterojunction achieves exceptionally high C ₂ H ₄ productivity and selectivity in photocatalytic CO ₂ reduction with water vapor in the absence of additives. In situ spectroscopic characterizations and theoretical calculations reveal that IS@COF‐Ni establishes a low‐energy pathway for electron and proton transfer, while the heterojunction interface effectively stabilizes the adsorbed CO (*CO) intermediate, facilitating C─C bond formation via coupling of adjacent *CO species to generate C ₂ H ₄ . This work provides a strategic approach for designing photocatalysts toward selective CO ₂ ‐to‐C ₂₊ conversion.

The photocatalytic oxidative dipolar [3 + 2] cycloaddition reaction is a promising green approach for producing pyrrolo[2,1-a]isoquinolines. However, developing sustainable cycloaddition methods with heterogeneous photocatalysts is still in its infancy, largely owing to their low reactivity and photostability. Herein, we propose a charge–oxygen synergy strategy through a dual-engineered covalent organic framework (COF) by integrating π-spacers with donor–acceptor motifs to promote intermolecular cycloaddition. Systematic analyses reveal that electron-deficient thiadiazole units significantly enhance exciton dissociation efficiency, while a fully conjugated acetenyl spacer promotes spontaneous oxygen adsorption to stabilize endoperoxide intermediate species. This synergistic interplay between charge separation and oxygen activation significantly boosts reactive oxygen species generation, enabling efficient C–H bond activation under visible light. Remarkably, the BTDE-COF efficiently promotes dipolar [3 + 2] cycloaddition, achieving up to 97.1% yield with a broad substrate scope under visible light irradiation, while enabling a gram-scale synthesis. This work suggests that strategically engineering COFs has the potential to foster a variety of visible light-mediated energy-transfer processes.

A topological spatial engineering strategy was proposed to precisely regulate dipole polarization and active sites in conjugated microporous polymers, achieving high photocatalytic CO ₂ -to-CH ₄ conversion activity and selectivity.

The synergy between Co and porphyrin–bicarbazole COFs establishes dual-channel charge transport pathways, enhancing charge separation and boosting CO₂ photoreduction performance.

Covalent organic framework (COF) has attracted increasing interest in photocatalytic CO₂ reduction, but it remains a challenge to achieve high conversion efficiency owing to the insufficient active site and fast charge recombination. Rationally optimizing the electronic structures of COF to regulate the local charge of active sites precisely is the key point to improving catalytic performance. Herein, intercalated single Co sites coordinated by imine‐N motifs have been designed by using trinuclear copper‐based imine‐COFs with distinct electronic moieties via a molecular engineering strategy. It is confirmed that the charge delivery property and local charge distribution of these heterometallic frameworks can be profoundly influenced by electronic structures. Among these featured structures with mixed‐state copper clusters, Co/Cu₃‐TPA‐COF stands out for an exceptional photocatalytic CO₂ reduction activity and tunable syngas (CO/H₂) ratio by changing various bipyridines. Experimental and theoretical results indicate that interlayer Co‐imine N motifs on the donor¹‐acceptor‐donor² structures facilitate the formation of a highly separated electron‐hole state, which effectively induces the oriented electron transfer from dual electron donors to Co centers, achieving an enhanced CO₂ activation and reduction. This work opens up an avenue for the design of high‐performance COF‐based catalysts for photocatalytic CO₂ reduction.

Covalent organic framework (COF) has attracted increasing interest in photocatalytic CO₂ reduction, but it remains a challenge to achieve high conversion efficiency owing to the insufficient active site and fast charge recombination. Rationally optimizing the electronic structures of COF to regulate the local charge of active sites precisely is the key point to improving catalytic performance. Herein, intercalated single Co sites coordinated by imine‐N motifs have been designed by using trinuclear copper‐based imine‐COFs with distinct electronic moieties via a molecular engineering strategy. It is confirmed that the charge delivery property and local charge distribution of these heterometallic frameworks can be profoundly influenced by electronic structures. Among these featured structures with mixed‐state copper clusters, Co/Cu₃‐TPA‐COF stands out for an exceptional photocatalytic CO₂ reduction activity and tunable syngas (CO/H₂) ratio by changing various bipyridines. Experimental and theoretical results indicate that interlayer Co‐imine N motifs on the donor¹‐acceptor‐donor² structures facilitate the formation of a highly separated electron‐hole state, which effectively induces the oriented electron transfer from dual electron donors to Co centers, achieving an enhanced CO₂ activation and reduction. This work opens up an avenue for the design of high‐performance COF‐based catalysts for photocatalytic CO₂ reduction.

Single cadmium sites on covalent organic frameworks promote adsorption and activation of CO₂to efficiently catalyze cyclization of propargylic amines.