Donor-acceptor type covalent organic frameworks （D-A COFs） represent a new category of porous organic materials synthesized by incorporating donor （D） units and acceptor （A） units into the main backbones of covalent organic frameworks. These materials combine the advantages of precisely designable topological structures， flexibly tunable pore sizes， and a rich variety of active sites， thus exhibiting enormous application potential in diverse fields such as photocatalysis， molecular separation， and energy storage and conversion. Compared with their three-dimensional （3D） or one-dimensional （1D） counterparts， two-dimensional （2D） D-A COFs possess distinct advantages： the alternately arranged D-A units on their planar structures can form a large number of heterojunctions， and the ordered interlayer stacking structures of the 2D frameworks can facilitate more efficient electron separation， thereby significantly enhancing the optoelectronic properties of the materials. Among various linkage modes used for constructing 2D COFs， imine-linked 2D D-A COFs have emerged as a research hotspot among scientists and researchers， owing to their simple synthetic methods， high crystallinity， and prominent performance advantages. This paper systematically outlines the fundamental building units of 2D imine D-A COFs， comprehensively summarizes their construction strategies and research progress in the fields of photocatalysis and biological phototherapy， deeply analyzes the current challenges faced in their applications in photocatalysis and phototherapy， and further prospects their future development directions.

Contents

1 Introduction

2 The building units of 2D imine D-A COFs

2.1 Selection of D Units

2.2 Selection of A Units

3 Construction strategies and applications of 2D imine D-A COFs

3.1 Photocatalytic H₂ evolution

3.2 Photocatalytic CO₂ reduction

3.3 Photocatalytic H₂O₂ generation

3.4 Photocatalytic organic transformation

3.5 Photocatalytic pollutant degradation

3.6 Phototherapy

4 Conclusion and outlook