Proton-conducting hydrogen-bonded nanochannels encapsulating perylene-based photocatalysts for solar hydrogen evolution

Abstract

Organic semiconductor photocatalysts provide a promising platform for solar hydrogen evolution by integrating light harvesting, exciton dynamics, and interfacial catalysis. However, in most organic semiconductors, slow proton transport through hydrophobic domains decouples photogenerated electrons from proton-coupled electron transfer and limits activity. Here we encapsulate perylenetetracarboxylic acid dianhydride (PTCDA) into a hydrogen-bonded organic framework (HOF) of H₄TBAPy linkers to build proton-conductive nanochannels around photoactive π-stacks. The hydrogen-bond network supports proton diffusion along confined pathways, increasing proton conductivity from 0.7 to 9.6 mS cm⁻¹, while the π–π stacked heterojunction generates an internal electric field that enhances interfacial charge separation. As a result, the PTCDA-in-HOF composite achieves a hydrogen evolution rate of 709.05 mmol g⁻¹ h⁻¹ with an apparent quantum efficiency of 29.4% at 450 nm and robust cycling stability. By coupling proton-transport engineering with organic semiconductor design, this work clarifies the role of local proton availability in organic photocatalysts and guides optimization of solar hydrogen fuel production.