High-performance heterostructured CdS/Ba_1-xSr_xTiO₃ system with unique synergism for photocatalytic H₂ evolution

This study demonstrates the design and synthesis of heterostructured CdS/Ba_1-xSr_xTiO₃ composites that exhibit outstanding photocatalytic activity and long-term durability for H₂ evolution from an aqueous solution containing the sacrificial agent (Na₂S/Na₂SO₃) without loading any noble metals as cocatalysts or reagents for regeneration. The excellent performance of this heterostructured catalyst is due to the unique synergetic effect between CdS and Ba_1-xSr_xTiO₃. In this system, CdS not only functions as a high-activity photocatalyst absorbing light to generate electrons but also acts as a cocatalyst accepting the photogenerated electrons from Ba_1-xSr_xTiO₃ for H₂ evolution, while Ba_1-xSr_xTiO₃ serves as captors of photoholes of CdS. In this way, the heterostructured composites can efficiently block the recombination of photogenerated electrons and holes, leading to a significant improved harvest of photogenerated electrons for H₂ evolution. In the meantime, the photocorrosion of CdS can be greatly alleviated due to fast moving photogenerated holes of CdS, contributing a long-term stability of the designed heterostructured system.