Construction of oxygen vacancies on Cu-COF as electron collector for high efficient photocatalytic hydrogen evolution

Abstract

Abstract Oxygen vacancies (OVs) play an essential role in photocatalytic hydrogen evolution, but the covalent organic frameworks (COFs) barely contain OVs due to their strong and stable covalent bonding. In this work, OVs are constructed on single atom Cu loaded COF-TpPa as electron collector to facilitate the transfer and utilization of electrons. Experiment and theoretical simulation proved that the synergistic effect between OVs and single-atom Cu greatly improves the efficiency of photogenerated carrier separation, decreases the activated energy and achieves a high apparent quantum efficiency of 20% at 420 nm. As electron collector, OVs transfer the collected electrons to Cu2+ to reduce Cu2+ to Cu1+, and then Cu1+ reduce the protons in the water to produce H2 and turn back to Cu2+, realizing the in-situ regeneration of Cu Active site. This study provides a brand-new modification method for COFs, disclosing the great potential of OV-COFs in visible light photocatalysis.