The Synthesis of TiO2 Nanotube Arrays as Electron Conductor for Photovoltaic Reactions

• Main Authors: Cynthia Dewi, 辛西亞
• Other Authors: Hsi-sheng Teng
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/61347614839220684980

碩士 === 國立成功大學 === 化學工程學系碩博士班 === 97 === Nanotubes structures have drawn interests for its high degree of crystallinity and high surface area to volume ratio which provides better electron transport when it is used as the electron conductor. Anatase TiO2 has been known as a good material for photocatalytic applications since it has wide band gap (3.1 eV) which relates to the UV light absorption. This research is focused on synthesizing the TiO2 nanotubes as the electron conductor for photovoltaic reactions; by anodizing Ti foil (vs Pt foil as the counter electrode) in F- ions containing electrolyte solution. The electrolyte solutions used for the anodic oxidation are 0.5 wt% NH4F in ethylene glycol or glycerol, modified by adding 10 wt% dimethyl sulfoxide (DMSO) to enhance the nanotube formation. TiO2 nanotubes obtained were then used as the substrate for CdS deposition using chemical bath deposition (CBD) method, and then were tested for the photoresponse under visible light illumination. It is found that the TiO2 samples obtained from the anodization of Ti foil for 24 hours gave the highest photocurrent under UV light illumination. It is also found that the samples anodized in glycerol electrolytes are more organized and the nanotubes wall is smoother than those anodized in ethylene glycol electrolytes. The addition of DMSO has been proven to enhance the nanotubes structure uniformity and hence performed higher photoresponse. The CdS deposited TiO2 nanotubes exhibit high photocurrent, showing that the TiO2 nanotubes synthesized in this research can be used as the electron conductor for the photovoltaic reactions.