Table of Contents
Journal of Materials
Volume 2013, Article ID 703985, 7 pages
http://dx.doi.org/10.1155/2013/703985
Research Article

High-Efficiency Photochemical Water Splitting of CdZnS/CdZnSe Nanostructures

Department of Chemistry, National Taiwan University, 1, Section 4, Roosevelt Road, Taipei 106, Taiwan

Received 19 December 2012; Accepted 5 February 2013

Academic Editor: Alfonso Castiñeiras

Copyright © 2013 Chen-I Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

We have prepared and employed TiO2/CdZnS/CdZnSe electrodes for photochemical water splitting. The TiO2/CdZnS/CdZnSe electrodes consisting of sheet-like CdZnS/CdZnSe nanostructures (8–10 m in length and 5–8 nm in width) were prepared through chemical bath deposition on TiO2 substrates. The TiO2/CdZnS/CdZnSe electrodes have light absorption over the wavelength 400–700 nm and a band gap of 1.87 eV. Upon one sun illumination of 100 mW cm−2, the TiO2/CdZnS/CdZnSe electrodes provide a significant photocurrent density of 9.7 mA cm−2 at −0.9 V versus a saturated calomel electrode (SCE). Incident photon-to-current conversion efficiency (IPCE) spectrum of the electrodes displays a maximum IPCE value of 80% at 500 nm. Moreover, the TiO2/CdZnS/CdZnSe electrodes prepared from three different batches provide a remarkable photon-to-hydrogen efficiency of 7.3 ± 0.1% (the rate of the photocatalytically produced H2 by water splitting is about 172.8 mmol·h−1·g−1), which is the most efficient quantum-dots-based photocatalysts used in solar water splitting.