Synthesis and characterization of highly ordered TiO sub(2) nanotube arrays for hydrogen generation via water splitting

• Published in: Materials chemistry and physics Vol. 129; no. 1-2; pp. 35 - 39
• Main Authors: Sun, Kao-Chen, Chen, Ying-Chieh, Kuo, Ming-Yuan, Wang, Hong-Wen, Lu, Yung-Fang, Chung, Jen-Chieh, Liu, Yu-Chang, Zeng, Yu-Zhen
• Format: Journal Article
• Language: English
• Published: 15.09.2011
• Subjects: Anodizing; Arrays; Nanomaterials; Nanostructure; Platinum; Pore size; Porosity; Titanium dioxide
• ISSN: 0254-0584
• DOI: 10.1016/j.matchemphys.2011.03.081

Highly ordered TiO sub(2) nanotube arrays (TNA) have been synthesized by anodization of Ti foils using an established electrochemical process. The parameters such as anodization potentials and durations have been varied to fabricate the specific morphology of TNA. In addition, Pt nanoparticles were deposited on these TNA via microwave irradiation. The photocurrent density-voltage (J-V) properties induced by the standard AM 1.5 solar simulator have been characterized using a potentiostat meter. The efficiency of photoelectrocatalytic effect of the large-pore-sized TNA (=120nm) is found to be higher than those of the TNA in smaller pore sizes ( less than or equal to 100nm). TNA with smaller pore sizes exhibit lower surface areas, and therefore, inferior photo-current efficiency to those of TNA with larger pore sizes. The low surface area of smaller-pore-sized TNA was resulted from the shorter tube length obtained at smaller anodizing voltages. Deposition of Pt nanoparticles on TNA was successfully accomplished using microwave irradiation technique. An enhanced hydrogen generation rate of 0.613mlh super(-1) cm super(-2) ( approximately equal to 25.0 mu mol h super(-1) cm super(-2)) was obtained on these Pt-deposited TNA compared to the 0.313mlh super(-1) cm super(-2) ( approximately equal to 12.8 mu mol h super(-1) cm super(-2)) of pristine TNA in a solution of methanol and water (1:1 ratio).