Photocatalytic Hydrogen Evolution with Conjugated Polymers: Structure–Property Insights and Design Strategies

Semiconducting polymer‐based photocatalysts have emerged as a promising platform for solar‐driven hydrogen production, offering tunable optoelectronic properties and synthetic versatility. This review systematically categorizes these materials into single‐component, multicomponent, and hybrid systems that integrate synthetic and biological components, each with distinct structural and mechanistic considerations. In single‐component systems, the influence of molecular polarity, backbone modifications, and charge transport pathways on exciton dynamics and catalytic performance is focused. In contrast, multicomponent systems exploit the complex interplay between the donor and acceptor materials, where morphology control, interfacial tuning, and intermolecular interactions collectively govern charge transport, recombination suppression, and catalytic activity. Hybrid systems extend these concepts by integrating semiconducting polymers with biological components and combining polymeric light‐harvesting capabilities with biocatalytic precision. By establishing clear structure–property relationships across these categories, the current design constraints and performance bottlenecks in polymer‐based hydrogen catalysts are critically assessed. Furthermore, not only material design strategies but also the role of advanced optical analysis, morphology characterization, and computational calculations (including machine learning‐guided materials discovery) in accelerating the rational design of next‐generation photocatalysts are discussed. This review provides a comprehensive roadmap for the development of high‐performance polymeric systems for sustainable hydrogen production, bridging fundamental molecular design principles with practical applications.