Interface π - d conjugation enhanced photocatalytic photo induced charge transfer in COF covalently linked with amino-Zn0.4Cd0.6S

The focus of this study is to effectively enhance photocatalytic activity by strategically combining inorganic and organic semiconductors in heterojunctions. The challenge lies in seamlessly integrating these different components. In this study, we successfully fabricated an inorganic organic bridge heterojunction between COF (covalent organic framework) and metal sulfides, and connected them through stable covalent bonds. This method achieves efficient photocatalytic hydrogen evolution (H) from water (H2O), marking an important milestone. Comparing the performance of our ZCS-COF hybrid material with individual components (i.e. pure TpPa-1-COF and amine ZnCdS (ZCS)), we observed a significant improvement in photocatalytic efficiency under visible light irradiation. Of particular note is the ZCS-COF-20 mixture, which exhibits a photocatalytic hydrogen production rate of up to 11.3 mmol/h. This rate is ten times higher than the original TpPa-1-COF. This enhancement can be attributed to the π - d conjugation effect at the interface within the heterojunction. These effects promote the transfer of electrons from metal sulfides to COFs through covalent bonds, ensuring effective charge separation and transfer. Therefore, the obtained mixture exhibits excellent photocatalytic activity and stability.