Surface engineering of 2D carbon nitride with cobalt sulfide cocatalyst for enhanced photocatalytic hydrogen evolution

It is a great challenge to design efficient noble-metal-free cocatalysts used in hydrogen production under visible light irradiation. Herein, it is demonstrated that a cobalt-sulfide material (Co${}_9$S${}_8$) with the advantages of excellent functionality of charge transfer can be used as an effective cocatalyst to improve the photocatalytic hydrogen evolution of 2D graphitic carbon nitride (2D g-C${}_3$N${}_4$). Interestingly, the developed Co-N${}_x$ bonds can strengthen the interface connection and ensure effective charge migration. Finally, the photocatalytic hydrogen evolution activity can be greatly improved. The optimal catalyst (20% Co${}_9$S${}_8$/2D g-C${}_3$N${}_4$) shows 237.9 µmol hydrogen evolution at 5 h, which is 140 times that of 2D g-C${}_3$N${}_4$. The good result indicates the positive role of the Co${}_9$S${}_8$ cocatalyst for active site engineering on 2D g-C${}_3$N${}_4$. (© 2021 Wiley‐VCH GmbH)