Micellization of Organic Conjugated Polymers toward Functional Nanomaterials for Photocatalytic Applications

Organic conjugated polymers (CPs) with an extended π-conjugated backbone exhibiting unique photophysical and chemical properties (e.g., good chemical stability, tunable light absorption, superior charge mobility, etc.) have been developed as promising photosensitizers for wide photocatalytic applications. Most of the reviews concerning CPs for photocatalytic applications focus on the structural design of CPs to achieve unique photophysical properties including broad absorption spectrum, high molar absorption coefficient, and low photobleaching. Construction of CPs into porous topological structures provides rich active sites. Moreover, the crystallinity of CPs facilitates photoinduced exciton transport across the polymeric backbone. However, the inherent hydrophobic character of these CPs exhibits low solubility in aqueous conditions, resulting in the existence of photoinduced exciton recombination, which would limit their photocatalytic applications. Micellization of CPs with hydrophilic functional groups via covalent/noncovalent interactions to construct the conjugated polymeric nanomaterials (CPNs) with improved surface wettability is an efficient approach to the construction of high-performance photocatalysts, resulting in their high dispersion stability in an aqueous solution and enhanced electron transfer from the photocatalyst to the reactant by decreasing their interfacial free energy. In this perspective, we provide a critical overview of the recent progress on the design and synthesis of the CPNs, focusing particularly on the relationship between the morphology and size of CPNs and their optoelectronic properties. Moreover, their photocatalytic applications including organic pollutant degradation, photoinduced chemical reactions, hydrogen evolution, CO₂ fixation, and medical therapy are discussed systematically. The current challenges and perspectives of CPNs for photocatalytic applications are also highlighted.