• 文献标题:   TiO2 Nanotube Array-Graphene-CdS Quantum Dots Composite Film in Z-Scheme with Enhanced Photoactivity and Photostability
  • 文献类型:   Article
  • 作  者:   XIAN JJ, LI DZ, CHEN J, LI XF, HE M, SHAO Y, YU LH, FANG JL
  • 作者关键词:   nanotube, composite, zscheme, photoelectrochemistry, photocatalysi
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:   Fuzhou Univ
  • 被引频次:   92
  • DOI:   10.1021/am5029999
  • 出版年:   2014

▎ 摘  要

The most efficient solar energy utilization is achieved in natural photosynthesis through elaborate cell membrane with many types of molecules ingeniously transferring photogenerated electrons to reactants in a manner similar to the so-called Z-scheme mechanism. However, artificial photosynthetic systems based on semiconductor nanoparticles are inevitably accompanied by undesired non-Z-scheme electron transfer and back reactions, which adversely affect the photoactivity and photostability of the systems. Herein, we report on a novel Z-scheme system with an electrochemically converted graphene (GR) film as the electron mediator interlayer contacted with both TiO2 nanotube (TNT) array and CdS quantum dots (CdS QDs) on two sides. The obtained TiO2 nanotube array graphene CdS quantum dots (TNT-GR-CdS) composite film shows higher photoelectric response and photocatalytic activities than other bare TNT, TNT-CdS, TNT-GR, and TNT-CdS-GR. Moreover, compared to TNT-CdS, the activity stability is significantly improved, and the residual amount of Cd element in reaction solution is reduced similar to 8 times over TNT-GR-CdS. Various measurements of photoelectrochemistry and radicals reveal that the enhanced photoactivity and photostabilities of TNT-GR-CdS are due to the efficient spatial separation of the photogenerated electron hole pairs and the restricted photocorrosion of CdS via an efficient Z-scheme mechanism under simulated sunlight.