Two-dimensional semiconducting covalent organic frameworks for photocatalytic solar fuel production

Two-dimensional covalent organic frameworks (COFs) are an emerging class of semiconducting materials for photocatalysis solar fuel production. They uniquely feature compositional and structural diversities (as opposed to inorganic semiconductors) as well as high crystallinity (as opposed to other organic semiconductors), and thereby hold great potential that is just beginning to be unveiled. Here, we provide an up-to-date account of the latest advances on the design and engineering of COF-based materials for photocatalytic H2 production or CO2 reduction. The review begins with an introduction of the background and fundamentals about COF-based photocatalysis. It is then followed by discussion about recent progress on their preparation, understanding of charge dynamics and strategies for improving photocatalytic performances. A short perspective on the opportunities and further directions is presented at the end.