Sonochemistry synthesis of Bi2S3/CdS heterostructure with enhanced performance for photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution from water splitting is an efficient, eco-friendly method for the conversion of solar energy to chemical energy. A great number of photocatalysts have been reported but only a few of them can respond to visible-light. Metal sulfides, a class of visible-light response semiconductor photocatalysts for hydrogen evolution and organic pollutant degradation, receive a lot of attention due to their narrow band gaps. Herein, we report the sonochemical synthesis of Bi₂S₃/CdS nanocrystal composites with microsphere structure at mild temperature. The phases of Bi₂S₃ and CdS can be observed obviously in HRTEM image. The heterostructure consisting of the two species of nanocrystals plays a key role in separating photo-generated charge carriers. Photocatalytic activities for water splitting are investigated under visible-light irradiation (λ > 400 nm) and an enhanced photocatalytic activity is achieved. The initial rate of H₂ evolution is up to 5.5 mmol h⁻¹ g⁻¹ without resorting to any cocatalysts.