Organic Donor‐Acceptor Systems for Photocatalysis

Abstract

Organic semiconductor materials are considered to be promising photocatalysts due to their excellent light absorption by chromophores, easy molecular structure tuning, and solution‐processable properties. In particular, donor‐acceptor (D‐A) type organic photocatalytic materials synthesized by introducing D and A units intra‐ or intermolecularly, have made great progress in photocatalytic studies. More and more studies have demonstrated that the D‐A type organic photocatalytic materials combine effective carrier separation, tunable bandgap, and sensitive optoelectronic response, and are considered to be an effective strategy for enhancing light absorption, improving exciton dissociation, and optimizing carrier transport. This review provides a thorough overview of D‐A strategies aimed at optimizing the photocatalytic performance of organic semiconductors. Initially, essential methods for modifying organic photocatalytic materials, such as interface engineering, crystal engineering, and interaction modulation, are briefly discussed. Subsequently, the review delves into various organic photocatalytic materials based on intramolecular and intermolecular D‐A interactions, encompassing small molecules, conjugated polymers, crystalline polymers, supramolecules, and organic heterojunctions. Meanwhile, the energy band structures, exciton dynamics, and redox‐active sites of D‐A type organic photocatalytic materials under different bonding modes are discussed. Finally, the review highlights the advanced applications of organic photocatalystsand outlines prospective challenges and opportunities.

Modulating the Photophysical Properties of Twisted Donor–Acceptor–Donor π-Conjugated Molecules: Effect of Heteroatoms, Molecular Conformation, and Molecular Topology

“…Organic π-conjugated donor−acceptor (D−A) compounds have played pivotal roles in contemporary science, leading to a multitude of applications including organic photovoltaics, 5 organic field-effect transistors, 6 and photocatalysis. 7 Notably, the past decade has seen remarkable progress in D−A-type organic emitters exhibiting thermally activated delayed fluorescence (TADF). 8 TADF is a crucial photophysical phenomenon wherein triplet excitons are thermally converted to singlet excitons via reverse intersystem crossing (RISC), leading to delayed emission from the resultant singlet excitons (Figure 1a).…”

“…Organic π-conjugated donor–acceptor (D–A) compounds have played pivotal roles in contemporary science, leading to a multitude of applications including organic photovoltaics, organic field-effect transistors, and photocatalysis . Notably, the past decade has seen remarkable progress in D–A-type organic emitters exhibiting thermally activated delayed fluorescence (TADF) .…”