Facile preparation of Z-scheme CdSAgTiO2 composite for the improved photocatalytic hydrogen generation activity

Photocatalytic hydrogen evolution is a prospective approach to solve the problem about energy crisis by fossil fuel combustion . As the good candidate to generate hydrogen under visible light irradiation , the rapid charge recombination and easy photocorrosion of pure CdS nanomaterials limited its hydrogen generation activity and photocatalytic stability. Here we constructed a novel ternary Z-scheme CdS Ag TiO 2 composite based on CdS nanowires by a three-step process to solve this problem. Compared with CdS TiO 2 and CdS, the Z-scheme CdS Ag TiO 2 composites could obviously extend the light-absorption region, accelerate the transfer rate of charge-separation, and possess stronger redox capability. The prepared Z-scheme CdS Ag TiO 2 composites show high photocatalytic hydrogen evolution rate of 1.91 mmol h −1  g −1 , which is 1.50 and 2.45 times that of CdS TiO 2 heterojunction and pure CdS nanowires. The Z-scheme photocatalytic system exhibits the synergetic effects due to more efficient charge transfer and surface plasmon resonance absorption. Ag nanoparticles used as electron mediator could decrease the recombination of the photocarriers, alter the path of charge transfer and suppress the photocorrosion. This work opens up a new way for the novel Z-scheme photocatalytic systems that suppress the photocorrosion of CdS, and has a promising application in the photocatalytic water splitting.