Open Access Nano Express

Synthesis and photoelectrochemical response of CdS quantum dot-sensitized TiO2 nanorod array photoelectrodes

Yunxia Hu, Baoyuan Wang, Jieqiong Zhang, Tian Wang, Rong Liu, Jun Zhang, Xina Wang and Hao Wang*

Author affiliations

Faculty of Physics and Electronic Technology, Hubei University, Wuhan, 430062, People’s Republic of China

For all author emails, please log on.

Citation and License

Nanoscale Research Letters 2013, 8:222  doi:10.1186/1556-276X-8-222

Published: 10 May 2013

Abstract

A continuous and compact CdS quantum dot-sensitive layer was synthesized on TiO2 nanorods by successive ionic layer adsorption and reaction (SILAR) and subsequent thermal annealing. The thickness of the CdS quantum dot layer was tuned by SILAR cycles, which was found to be closely related to light absorption and carrier transformation. The CdS quantum dot-sensitized TiO2 nanorod array photoelectrodes were characterized by scanning electron microscopy, X-ray diffraction, ultraviolet–visible absorption spectroscopy, and photoelectrochemical property measurement. The optimum sample was fabricated by SILAR in 70 cycles and then annealed at 400°C for 1 h in air atmosphere. A TiO2/CdS core-shell structure was formed with a diameter of 35 nm, which presented an improvement in light harvesting. Finally, a saturated photocurrent of 3.6 mA/cm2 was produced under the irradiation of AM1.5G simulated sunlight at 100 mW/cm2. In particular, the saturated current density maintained a fixed value of approximately 3 mA/cm2 without decadence as time passed under the light conditions, indicating the steady photoelectronic property of the photoanode.

Keywords:
Quantum dots; CdS; Nanocable arrays; SILAR