Onion-ring-like g-C3N4 modified with Bi3TaO7 quantum dots: A novel 0D/3D S-scheme heterojunction for enhanced photocatalytic hydrogen production under visible light irradiation

Photocatalytic H2 evolution is a clean and renewable process that converts solar energy into chemical energy through water splitting under solar light irradiation. Herein, zero-dimensional (0D) Bi3TaO7 (BTO) quantum dots/three-dimensional (3D) onion-ring-like g-C3N4 (OR-CN) S-scheme heterojunction catalyst is constructed to simulate the production of hydrogen by photocatalysis under sunlight irradiation through a solvothermal method for photocatalytic hydrogen production under visible light irradiation. Results reveal that BTO/OR-CN heterojunction exhibited much higher photocatalytic activity compared to the pure BTO and OR-CN, in which the optimal loading amount 0.3% BTO/OR-CN composite endows the optimal photocatalytic H2 evolution rate of 4891 μmol g−1 with the apparent quantum yield (AQY) at 420 nm of 4.1%. The enhancement of excellent photocatalytic H2 performance is due to the formation of S-scheme heterojunction structure between 0D BTO quantum dots and 3D OR-CN, which promotes the separation and migration of photogenerated carriers and significantly enhances the visible-light absorption capacity. This work offers a viable strategy to construct 0D/3D S-scheme heterojunction photocatalyst in the application of photocatalytic field under visible light.