Boosting the slow exciton dissociation of conjugated polymers (CPs) is of significance for their application in photocatalysis. Extensive research has been dedicated to improve the exciton separation efficiency through the rational molecular design, while constructing donor−π–acceptor (D−π–A) structures with larger π-electron delocalization to extend carrier migrating distance can further promote exciton dissociation. In this work, we reported the design and construction of D−π–A CP systems by using pyrene, dibenzo­[b,d]­thiophene 5,5-dioxide, and diethynylbenzene as the donor group, acceptor group, and π-linker units, respectively, for improving the photocatalytic performance. Density functional theory studies and experimental investigations reveal that the D−π–A structure can suppress charge recombination, minimize exciton binding energy, and extend the light absorption range, thereby improving the photocatalytic activity in comparison to the A−π–A and D−π–D structures. It is believed that this work can provide inspiration for the precise regulation of the D−π–A system by combining experiments and theoretical calculations, thereby enhancing the photocatalytic performance of CPs.

Photocatalysis can create a green way to produce clean energy resources, degrade pollutants and achieve carbon neutrality, making the construction of efficient photocatalysts significant in solving environmental issues. Conjugated polymers (CPs) with adjustable band structures have superior light-absorption capacity and flexible morphology that facilitate contact with other components to form advanced heterojunctions. Interface engineering can strengthen the interfacial contact between the components and further enlarge the interfacial contact area, enhance light absorption, accelerate charge transfer and improve the reusability of the composites. In order to throw some new light on heterojunction interface regulation at a molecular level, herein we summarize CP-based composites with improved photocatalytic performance according to the types of interactions (covalent bonding, hydrogen bonding, electrostatic interactions, π-π stacking, and other polar interactions) between the components and introduce the corresponding interface building methods, identifying techniques. Then the roles of interfaces in different photocatalytic applications are discussed. Finally, we sum up the existing problems in interface engineering of CP-based composites and look forward to the possible solutions.

Interface engineering can facilitate the self‐assembly of conjugated polymer‐based composites through a series of intermolecular interactions (covalent bonding, hydrogen bonding, dipole‐dipole interactions, electrostatic interactions, and π‐π stacking) between the components, further improving the photocatalysis process, which depends heavily on smooth charge transfer at the well‐formed interface. For more details, see the Review by C. Shi, J.‐J. Zou, et al. (DOI: 10.1002/chem.202202593)“.