Exciton Diffusion in Covalent Triazine Frameworks and its Role in Photocatalytic Redox Transformations

Covalent triazine frameworks (CTFs) are promising heterogeneous photocatalysts, yet the transport of photogenerated excitons and its effect on catalytic output remains poorly understood. Here, we show that excited-state diffusivity is a key determinant of photocatalytic performance. We compare two quinoline-based CTFs containing adjacent phenyl or pyridine units to assess the role of backbone conjugation, supported by DFT calculations. Experimentally determined exciton diffusivities are correlated with photocatalytic Cr(VI) reduction. Enhanced conjugation improves exciton transport and catalytic efficiency, establishing excited-state mobility as a key design parameter.