Enhanced photocatalytic degradation of methyl orange by CdS quantum dots sensitized platelike WO3 photoelectrodes

• Published in: Journal of Central South University 2015-12, Vol.22 (12), p.4551-4559
• Main Authors: Wen, Jin, Liu, Can-jun, Du, Yong, Hu, Chuan-yue, Tian, Xiu-ying
• Format: Article
• Language: English
• Subjects: Engineering; Metallic Materials
• ISSN: 2095-2899; 2227-5223
• DOI: 10.1007/s11771-015-3005-9

CdS quantum dots sensitized platelike WO 3 photoelectrodes were successfully synthesized by a facile hydrothermal method and a modified chemical bath deposition (CBD) technique. To further improve the stability of the photoelectrodes in alkaline environment, the platelike WO 3 films were treated with TiCl 4 to form a nano-TiO 2 buffer layer on the WO 3 plate surface before loading CdS QDs. The resulting electrodes were characterized by using XRD, SEM, HR-TEM and UV-vis spectrum. The photocatalytic activity of the resulting electrodes was investigated by degradation of methyl orange (MO) in aqueous solution. The photoelectrochemical (PEC) property of the resulting electrodes was also characterized by the linear sweep voltammetry. The results of both the degradation of MO and photocurrent tests indicated that the as-prepared CdS QDs sensitized WO 3 platelike photoelectrodes exhibit a significant improvement in photocatalytic degradation and PEC activity under visible light irradiation, compared with unsupported CdS QDs electrodes. Significantly, coating the WO 3 plates with nano-TiO 2 obviously facilitate the charge separation and retards the charge-pair recombination, and results in a highest activity for QDs CdS/TiO 2 /WO 3 photoelectrodes.