Wide-spectrum response urchin-like Bi2S3 spheres and ZnS quantum dots co-decorated mesoporous g-C3N4 nanosheets heterojunctions for promoting charge separation and enhancing photothermal-photocatalytic performance

Abstract

Wide-spectrum response ZnS quantum dots/urchin-like Bi2S3 spheres/mesoporous g-C3N4 nanosheets ternary photocatalysts are prepared via the hydrothermal and template-calcination processes. The deposited ZnS quantum dots with the size of ~10 nm are bedecked on the surface of mesoporous g-C3N4 nanosheets uniformly. Mesoporous g-C3N4 performs as a bridge for electrons transferring among the three semiconductor photocatalysts in ternary heterojunction structure. The photocatalytic H2 evolution for ZnS/Bi2S3/mesoporous g-C3N4 reaches to 663.3 µmol h−1 g−1 under the sunlight irradiation, which is approximately 5 times higher than that of pristine mesoporous g-C3N4; Moreover, the photocatalytic degradation of Bisphenol A is also up to 98.8% under the visible light irradiation; Surprisingly, the apparent reaction rate constant (k) of ZnS/Bi2S3/mesoporous g-C3N4 is approximately 5 times higher than mesoporous g-C3N4. The excellent photocatalytic performance may put down to the formation of ternary heterojunction and mesoporous structure, which could promote charges separation and offer more surface active sites, respectively, and the specific photothermal effect, which even has photo-response in the near infrared region. This work also offers a novel strategy for constructing other highly photocatalytic performance quantum dots-semiconductor photocatalysts.