II‐Scheme Heterojunction Frameworks Based on Covalent Organic Frameworks and HKUST‐1 for Boosting Photocatalytic Hydrogen Evolution

Abstract

Covalent organic frameworks (COFs) are one type of promising polymer semiconductors in solar‐driven hydrogen production, but majority of COFs‐based photocatalytic systems show low photocatalytic efficiency owing to lack of metal active sites. Herein, we reported II‐Scheme heterojunction frameworks based on COF (TpPa‐1) and metal‐organic framework (HKUST‐1) for highly efficient hydrogen production. The coordination bonding directed self‐assembly of HKUST‐1 on the surface of TpPa‐1 endows the heterojunction frameworks (HKUST‐1/TpPa‐1) with strong interface interaction, optimized electronic structures and abundant redox active sites, thus remarkably boosting photocatalytic hydrogen evolution. The hydrogen evolution rate for optimal HKUST‐1/TpPa‐1 is as high as 10.50 mmol g−1 h−1, which is significantly enhanced when compared with that of their physical mixture (4.13 mmol g‐1 h‐1), TpPa‐1 (0.013 mmol g‐1 h‐1) and Pt‐based counterpart (6.70 mmol g‐1 h‐1). This work offers a facile approach to the construction of noble‐metal‐free II‐Scheme heterojunctions based on framework materials for efficient solar energy conversion.