Photocatalytic conversion of CO₂ into value–added chemicals under visible light irradiation is very appealing but challenging due to the easy recombination of hole–electron pairs in traditional photocatalysts. π–π stacking interactions can be favorable for efficient separation and transfer of photo–irradiated charges to promote photocatalysis, but are rarely studied in crystalline porous frameworks like covalent organic frameworks (COFs). Herein, we report a series of thienothiophenes–porphyrin based 2D COFs, denoted as TT–Por(M)–COF (M = 2 H/Co/Cu/Ni), which show enhanced intralayer and interlayer charge separation and migration due to the donor-acceptor heterojunctions and π–stacked columns. The TT–Por(Co)–COF achieves enhanced CO evolution rate than COF–366–Co without the heterojunctions and π–columns (10.05 mmol g^–1 h^–1 versus 7.10 mmol g^–1 h^–1) under visible light irradiation. This work not only shows the important role of π–π stacking interactions of COFs for CO₂ conversion, but also provides insight into the mechanistic aspect for photocatalysis.

_{CO 2}的光催化转化在可见光照射下转化为增值化学品非常有吸引力，但由于传统光催化剂中的空穴-电子对很容易重组，因此具有挑战性。π-π 堆积相互作用有利于光照射电荷的有效分离和转移以促进光催化，但很少在共价有机骨架 (COF) 等结晶多孔骨架中进行研究。在此，我们报告了一系列基于噻吩并噻吩-卟啉的二维 COF，表示为 TT-Por(M)-COF (M = 2 H/Co/Cu/Ni)，由于供体-受体异质结和 π 堆积柱。与没有异质结和 π 柱的 COF-366-Co 相比，TT-Por(Co)-COF 实现了更高的 CO 释放速率（10.05 mmol g ^–1 h ^–1对比 7.10 mmol g ^–1 h ^–1 ) 在可见光照射下。这项工作不仅展示了 COF 的 π-π 堆积相互作用在 CO ₂转化中的重要作用，而且还提供了对光催化机理方面的深入了解。