Optoelectronic materials as emerging photocatalysts: opportunities in sustainable organic synthesis

To overcome the energy and environmental crisis, the development of efficient, sustainable photocatalysts to convert inexhaustible solar energy into chemical energy is of great significance. Due to their unique optoelectronic properties, organic electronic materials have been translated into the photocatalytic field. These emerging photocatalysts are attractive because of their metal-free nature, chemical stability, and structural diversity. However, as many small molecules fail to absorb visible light solely, incorporating them into crosslinked frameworks is found to be an effective strategy to extend the conjugation and enhance visible-light absorption. In addition, the photophysical properties of these heterogeneous materials can be adjusted through structural modification and linkage engineering. Finally, these insoluble photocatalysts exhibit good recyclability and reusability. As a representative illustration, this feature article describes recent examples of the use of two types of organic electronic materials including phenothiazine and truxene in heterogeneous photocatalytic organic transformations. The synthesis and key photophysical properties of both organic electronic material-based photocatalysts are discussed combined with specific synthetic applications. We anticipate this feature article will stimulate the implementation of more diverse organic electronic materials in the field of photocatalysis, which may lead to unprecedented synthetic applications.