Facile preparation of Z-scheme CdSAgTiO2 composite for the improved photocatalytic hydrogen generation activity. (27th September 2018)

• Record Type: Journal Article
• Authors: Zhao, Wei; Liu, Jincheng; Deng, Zhenyu; Zhang, Jinhong; Ding, Zhongxiang; Fang, Yanxiong
• Is Part Of: International journal of hydrogen energy. Volume 43:Number 39(2018)
• Page Start: 18232
• Page End: 18241
• Publication Date: 2018-09-27
• Subjects: Z-scheme -- Photocatalytic -- Hydrogen evolution -- CdSAgTiO2 -- CdS nanowires; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2018.08.026
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: 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 CdSAgTiO2 composite based on CdS nanowires by a three-step process to solve this problem. Compared with CdSTiO2 and CdS, the Z-scheme CdSAgTiO2 composites could obviously extend the light-absorption region, accelerate the transfer rate of charge-separation, and possess stronger redox capability. The prepared Z-scheme CdSAgTiO2 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 CdSTiO2 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. Graphical abstract: Highlights: The Z-scheme system consisting of CdSAgTiO2 was prepared through a three-step method. The extending light adsorption was resulted from the plasmon resonance absorption of Ag nanoparticals. The Z-scheme significantly increased the electron-hole separation with the stronger redox capability. The H2 generation rate for CdSAgTiO2 is 1.46, 1.50, and 2.51 times that for CdSAg, CdSTiO2 and CdS. Z-scheme system prevented photocorrosion of CdS and significantly improved the photocatalytic stability.