Photonics and Quantum Detection

Photo-electro-catalytic (PEC) solar-to-hydrogen conversion is a promising strategy for sustainable energy production but remains limited by complex material architectures and high catalyst loadings. Here, we demonstrate macroscopic photocatalytic hydrogen evolution from molecularly thin monolayers composed of perylene-platinum photocatalysts (PS-CAT) dyads and oligo(phenylene ethynylene) amphiphiles. These Langmuir-assembled membranes, deposited via roll-to-roll-compatible methods, form structurally defined layers with catalyst loadings as low as 1 mg m⁻². Upon visible light irradiation in aqueous ascorbate solution, turnover numbers exceeding 180 were achieved - outperforming homogeneous analogs. Structural and spectroscopic analyses - AFM (atomic force microscopy), PiFM (photo-induced force microscopy), PDS (photothermal deflection spectroscopy) - reveal intermolecular interactions and nanoscale separations as key factors enhancing catalytic activity. This study provides the first evidence of macroscopic hydrogen evolution from 2D molecular membranes and establishes a modular platform for future molecular PEC devices.