Cobalt coordinated olefin-linked covalent organic frameworks toward highly efficient photocatalytic hydrogen production

Covalent organic frameworks (COFs) have emerged as a crystalline porous materials for photocatalytic hydrogen production. However, the design of efficient COF-based catalyst for satisfactory solar-to-hydrogen energy conversion is still challenging. Here, cobalt was anchored on the bipyridine moieties in the framework of olefin- linked sp2c-COFdpy by convenient post-metalation (sp2c-COFdpy-Co). Experimental results showed that sp2c- COFdpy-Co exhibited wider visible light absorption region and quicker photogenerated e- /h + separation efficiency than sp2c-COFdpy. Photocatalytic experiments revealed that sp2c-COFdpy-Co was highly efficient for H2 production after photodeposition of Pt co-catalyst (Pt@sp2c-COFdpy-Co). The optimized Pt@sp2c-COFdpy-Co exhibited a high photocatalytic H2 production rate of 324.4 mu mol/h under visible light irradiation in the presence of 1.0 wt% Pt as co-catalyst, which was higher than Pt@sp2c-COFdpy-Fe and Pt@sp2c-COFdpy-Ni, and it was much higher than that of its counterparts and many reported works. This work provides new insights into design of highly efficient COF-based catalyst for photocatalytic H2 production.