Spatial charge separated two-dimensional/two-dimensional Cu-In2S3/CdS heterojunction for boosting photocatalytic hydrogen production

Two-dimensional (2D) beta indium sulfide ( β -In 2 S 3 ) shows great potential in photocatalytic hydrogen production due to its broad-spectrum response, relatively negative conduction band edge, high carrier mobility and low toxicity. However, the high charge recombination rate limits the application of In 2 S 3 . Here, we in-situ grew 2D cadmium sulfide (CdS) on the surface of In 2 S 3 doped with copper ions (Cu 2+ ) to construct a heterojunction photocatalyst that suppresses charge recombination. The in-situ grown method and shared sulfur composition were conducive to forming the efficient interface contact between In 2 S 3 and CdS, promoting charge transfer and showing the high spatial charge separation rate, resulting in a hydrogen production rate of 868 µmol g -1 h −1 . The induced Cu 2+ extended the light absorption range and stabilized the photocatalyst . By creating stable 2D/2D heterojunction photocatalysts with high charge separation efficiency, this work opens new possibilities for applying In 2 S 3 materials in photocatalytic hydrogen production.