Titanium dioxide (TiO 2 ) nanorods (NRs) are widely used as photoanodes in photoelectrochemical (PEC) solar fuel production because of their remarkable photoactivity and stability. In addition, TiO 2 NR electrode materials can be decorated with active CdS quantum dots (QDs) to expand the sunlight photon capture. The overall photoelectric conversion efficiency for TiO 2 NR or QD-sensitized TiO 2 NR electrode materials in PEC is typically dominated by their interfacial electron transfer (ET) properties. To understand the key factors affecting the ET, the anatase TiO 2 seed layer was added into the interface between the rutile TiO 2 NRs and fluorine-doped tin oxide (FTO) substrate. This seed layer enhanced the photocatalytic performance of both the TiO 2 NR and CdS QD-sensitized TiO 2 NR photoanodes in PEC. Time-resolved photoluminescence spectroscopy and PEC analyses, including Mott-Schottky, electrochemical impedance spectroscopy, and photovoltage (V ph ) measurements, were used to study the charge-carrier dynamics at the interfaces between the FTO, TiO 2 , and CdS QD. Analysis of the results showed that band alignment at the anatase/rutile junction between the TiO 2 and FTO promoted electron-collection efficiency (e EC ) at the FTO/TiO 2 interface and ET rate constant (k ET ) at the TiO 2 /CdS QD interface. Furthermore, 34% enhancement of the efficiency in hydrogen (H 2 ) generation demonstrated the potential of the TiO 2 seed-layer-mediated TiO 2 /CdS QD NR photoanode in the application of PEC solar fuel production. The current work represents new insights into the mechanism of ET in TiO 2 and TiO 2 /CdS QD NR, which is very useful for the development of photoelectrode materials in solar energy conversions.
All Science Journal Classification (ASJC) codes
- Materials Science(all)