Donor-engineered D-A nanophotocatalyst with dual surfactants-directed assembly for efficient photocatalytic hydrogen evolution

Organic semiconductors hold promise for photocatalytic hydrogen production, yet their performance is often limited by excitonic effects that hinder charge separation and transport. To overcome these challenges, we present a synergistic strategy combining donor-acceptor (D-A) molecular engineering with dual-surfactant-directed nanoassembly. A series of structurally analogous D-A molecules based on 4-([1,1′-biphenyl]-4-yl)-2,6-bis(4-cyanophenyl) pyridine-3,5-dicarbonitrile (CNP) were synthesized with systematic variation of donor-unit substituents. Among them, the methoxy-containing CNP, namely CNP501, exhibited a 26-fold higher hydrogen evolution rate than pristine CNP. Leveraging this, a dual-surfactant-induced self-assembly approach yielded the CNP501/DDBAB/SDBS nanophotocatalyst, which achieved an additional 12-fold enhancement in photoactivity, delivering a hydrogen production rate of 1093 mmol g –1 h –1 and an apparent quantum yield of 77.2% at 365 nm. The exceptional performance arises from two synergistic effects: (1) donor engineering, which modulates intrinsic molecular electric fields to promote exciton dissociation, and (2) surfactant-mediated morphological control, which optimizes hydrophilicity, minimizes interfacial charge-transfer resistance, and suppresses carrier recombination. Notably, dual-surfactant regulation uniquely enables multiple light scattering with tunable efficiency, a feature absent in single-surfactant systems.