Quantum-Dot-Sensitized Nitrogen-Doped ZnO for Efficient Photoelectrochemical Water Splitting

Fossil fuels have been used for several decades and have resulted in increased greenhouse gases and pollutants. Currently, clean and renewable energy is in demand. Hydrogen appears to be a good candidate for clean energy because the only product of its reaction with oxygen is water. Water splitting by solar energy is a potential method for the generation of hydrogen in future applications. This study investigates the use of a CdTe quantum-dot-sensitized ZnO:N nanowire arrays for water splitting. The proposed method resulted in considerably enhanced photocurrent and stability. The electronic structures of the ZnO:N materials are also determined by O K-edge X-ray absorption spectroscopy. The incorporation of nitrogen into the ZnO nanostructure is determined by X-ray photoelectron spectroscopy and Zn K-edge X-ray absorption spectroscopy; the nitrogen incorporation changes the electronic state and, thus, increases the water-splitting performance. We have prepared a photoelectrode by sensitization of a ZnO:N nanowire array by CdTe quantum dots. The photoelectrode improves the harvest of visible light significantly and, thus, enhances the photoelectrochemical cell performance. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.