Parallel Interface Engineering of Single‐Atom Pt/g‐C ₃ N ₄ and Selenoviologen for Durable Photocatalysis via Efficient Directional Electron Flow

ABSTRACT Photocatalysis offers a sustainable route for clean energy conversion, yet its efficiency is frequently constrained by uncontrolled charge‐carrier recombination and sluggish interfacial electron transfer. Here, we address this challenge by constructing a parallel photocatalytic interface through the dual covalent binding of selenoviologen electron mediators to defective g‐C 3 N 4 which is anchored with single‐atom Pt. This architecture forms a highly stable “electron overpass” that directs electron flow with exceptional efficiency. Ultrafast spectra and DFT calculations confirm that this overpass channels electrons from both photoexcited g‐C 3 N 4 and selenoviologen radical intermediates directly to the Pt catalytic sites. The system achieves a forward electron transfer rate of 0.043 L·g −1 ·s −1 , four times that of the single covalent binding control, and extends the charge carrier lifetime to 7998.8 ps. As a result, the photocatalyst delivers a remarkable hydrogen evolution rate of 3231.9 µmol·h −1 g −1 , while the concurrent anaerobic oxidation of benzylamine proceeds at 1390.6 µmol·h −1 g −1 . Crucially, the dual covalent binding affords outstanding durability, retaining 92% of the initial activity after six 24 h cycles, a nearly tenfold improvement over the conventional system. This work establishes parallel interface engineering as a general paradigm for directing electron flow, paving the way for advanced solar fuel production and artificial photosynthesis.