Hot-electron leading-out strategy for constructing photostable HOF catalysts with outstanding H2 evolution activity

Abstract

Improving photochemical stability of hydrogen-bonded organic frameworks (HOFs) is a prerequisite for design HOF photocatalysts for efficient solar energy conversion. Herein, efficiently leading-out hot-electrons was demonstrated as a new strategy for synthesizing photostable HOFs via introducing Pt nanoparticles as electron sinks into high crystalline nano-HOFs. The resulting Pt@nano-HOF exhibits extremely high hydrogen evolution activity and photochemical stability, subverting the traditional view of “frail HOFs”. Impressively, the maximum H2 evolution rate of 31.2 mmol/g/h represents the best performance among those of various crystalline framework materials. The acceleration of hot-electron transfer can be also achieved by introducing a planar [Co(qpy)(OH2)2]2+ molecule to form π-π stacking with framework, reaching a record H2 evolution rate of 14.8 mmol/g/h among all the covalent-/metal-organic framework and HOF-based photocatalysts without any noble metal components. This work highlights a new insight for improving the photochemcial stability of the catalysts, even for particularly unstable HOFs.