Organization of supramolecular assemblies of fullerene, porphyrin and fluorescein dye derivatives on TiO₂ nanoparticles for light energy conversion

详细信息	查看全文 | 推荐本文 |

• 作者：Taku Hasobe ; Shigeki Hattori ; Prashant V. Kamat ; Yasuteru Urano ; Naoki Umezawa ; Tetsuo Nagano and Shunichi Fukuzumi
• 关键词：Porphyrin ; Fullerene ; Fluorescein ; TiO₂ nanoparticles ; Light energy conversion
• 刊名：Chemical Physics
• 出版年：2005
• 期刊代码：18_03010104
• 类别：ch
• 出版时间：7 December 2005
• 卷：319
• 期：1-3
• 页码：243-252
• 文件大小：535 K

摘要

TiO₂ nanoparticles were modified with a porphyrin derivative, 5-[4-benzoic acid]-10,15,20-tris[3,5-di-tert-butylphenyl]-21H,23H-porphyrin (H₂P-COOH), and fluorescein derivatives, 9-[2-(3-carboxy-9,10-diphenyl)anthryl]-2,7-difluoro-6-hydroxy-3H-xanthen-3-one (DPAX-COOH) and 2′,7′-difluorofluorescein (FL-COOH). The dye-modified TiO₂ nanoparticles were deposited on nanostructured OTE/SnO₂ (OTE: optically transparent electrodes) together with nanoclusters of fullerene (C₆₀) from acetonitrile/toluene (3:1, v/v) using an electrophoretic deposition technique. The dye-modified TiO₂ composite electrodes [OTE/SnO₂/(dye + C₆₀)_n] have broad as well as high absorbance properties in the visible region, exhibiting the photo response under visible light excitation using redox couple. The incident photon to photocurrent efficiency (IPCE) for these electrodes increases in order: OTE/SnO₂/(H₂P)_n < OTE/SnO₂/(H₂P-COO–TiO₂)_n < OTE/SnO₂/(H₂P-COO–TiO₂ + C₆₀). The IPCE value can be further improved by replacing H₂P-COOH with a fluorescein derivative containing an electron donor moiety: DPAX-COOH (DPA: diphenylanthracene). The maximum IPCE value (42%) is obtained for OTE/SnO₂/(DPAX-COO–TiO₂ + C₆₀)_n under the bias of 0.2 V vs. SCE.