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 (Co9S8) 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-C3N4). 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% Co9S8/2D g-C3N4) shows 237.9 mu mol hydrogen evolution at 5 h, which is 140 times that of 2D g-C3N4. The good result indicates the positive role of the Co9S8 cocatalyst for active site engineering on 2D g-C3N4.