Crystalline Poly(triazine) Imide for Photoredox Catalysis.

Among the emerging polymeric photocatalysts, poly(triazine imide) (PTI) has gained significant attention due to its highly crystalline framework, well-defined electronic structure, and exceptional charge-transport properties. These unique features position PTI as an attractive platform for exploring structure-property-performance relationships in photoredox catalysis. This review summarizes recent advancements in PTI-based photocatalysts, with a particular focus on their enhanced performance in overall water splitting (OWS) and other applications. We analyze the fundamental structural and electronic characteristics that underpin photocatalytic activity. Furthermore, we discuss innovative synthetic methodologies and structural engineering strategies-including crystallinity control, electronic structure modulation, cocatalyst incorporation, and heterojunction design-aimed at optimizing charge separation, surface reaction kinetics, and active-site utilization. Recent progress in PTI-driven OWS, CO2 reduction, and other relevant processes is critically evaluated, along with the key challenges that impede efficiency and scalability. By elucidating the correlations between structure and its photocatalytic functions, this review offers design principles for the development of next-generation crystalline polymer photocatalysts, and provides valuable insights for advancing practical solar energy conversion technologies.