Photothermal effect of carbon dots for boosted photothermal-assisted photocatalytic water/seawater splitting into hydrogen

Herein, carbon dots were loaded on the surface of hollow tubular carbon nitride (CDs/TCN) via a two-step route of hydrothermal and calcination processes for photothermal-assisted photocatalytic water/seawater splitting into hydrogen full spectrum light irradiation. The introduction of CDs promotes the separation and transfer rate of photogenerated carriers, and provides active sites for the hydrogen precipitation reaction. Most importantly, with the assistance of the thermal insulation effect of TCN, the photothermal effect of CDs can greatly increase the surface temperature of CDs/TCN composite system, thus enhancing the photocatalytic H2 production performance. All the synthesized CDs/TCN composites exhibited efficient photocatalytic H2 production rates, the highest of which reached 12.94 mmol h−1 g−1 and 11.92 mmol h−1 g−1 from water and seawater splitting, respectively. This study provides a new idea for enhancing the photothermal-assisted photocatalytic water splitting into hydrogen using CDs with photothermal effect.