Photoelectrochemical properties of N/C-codoped TiO2 film electrodes prepared by reactive DC magnetron sputtering

• Published in: Journal of nanoscience and nanotechnology Vol. 10; no. 2; p. 1057
• Main Authors: Wu, Kee-Rong, Yeh, Chung-Wei, Hung, Chung-Hsuang, Chung, Chih-Yuan, Cheng, Li-Hsun
• Format: Journal Article
• Language: English
• Published: United States 01.02.2010
• ISSN: 1533-4880
• DOI: 10.1166/jnn.2010.1854

This paper aims to characterize the photoelectrochemical properties of the visible-light enabling titanium dioxide (TiO2) film electrodes prepared by codoping nitrogen (N) and a presputtered carbon film (C-film) onto indium tin oxide (ITO) glass substrates using a direct current (DC) magnetron sputtering technique. To improve its photoelectrochemical properties, different amount of C-doping sources, 2 h and 4 h C-film, are chose to prepare the N/C-codoped TiO2 film electrodes. Under visible-light (420 < lambda < 610 nm) illumination, a remarkable photocurrent density of 22 microA/cm2 is obtained for the N/C-TiO2 film electrode prepared with a 4 h C-film (NC(4)-T) at an applied potential of +1.2 V versus SCE. Under ultraviolet (lambda approximately 365 nm) illumination, the NC(4)-T film electrode also exhibits the highest photocurrent density of 0.23 mA/cm2 among all samples tested. A more negative flat band potential of NC(4)-T film electrode is attributed to the synergistic effect of N/C codoping. The XRD spectrum of the NC(4)-T film electrode shows mainly the well-crystallized anatase TiO2 phase and an extremely intense (211) plane. Thus, photoelectrochemical activity of the NC(4)-T film electrode can be ascribed to the well-crystallized columnar crystals with pores at its grain boundary, open surface morphology, which are revealed by SEM and TEM images, and a more negative flat band potential. The visible-light induced activity is mostly enhanced as a result of the synergistic effects of N/C-codoping into the TiO2 crystals. A potential application to photocatalytic splitting of water for hydrogen evolution using solar light is practically possible.