Single site Co-S anchored on carbon nitride as a highly active cocatalyst for photocatalytic hydrogen evolution

Abstract

The low utilization rate of photo-generated carriers in graphite-phase carbon nitride (g-C3N4) is the main factor limiting its photocatalytic performance. In this work, to begin with single-atom Co was inserted into the structure of g-C3N4, then it was vulcanized to prepare composite Co-S single-site in g-C3N4. The results show that the Co-S single-site cocatalyst was successfully synthesized and was stably anchored in the structure of g-C3N4. As an active site, it can not only enhance the reaction activity, but also capture electrons to provide transfer channels for the photo-generated carrier, thereby enhancing the photocatalytic hydrogen evolution performance of g-C3N4. The hydrogen production of Co-S single-site modified g-C3N4 reaches 72.85 μmol (per 0.02 g photocatalyst) under visible light, which is 9 times higher than that of pure g-C3N4. This work provides a reasonable method for the preparation of composite single-site cocatalyst.