Visible Light Sensitization of TiO2 Nanotubes by Bacteriochlorophyll-C Dyes for Photoelectrochemical Solar Cells

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• 作者：Lok-kun Tsui ; Justine Huang ; Michal Sabat ; Giovanni Zangari
• 刊名：ACS Sustainable Chemistry & Engineering
• 出版年：2014
• 出版时间：September 2, 2014
• 年：2014
• 卷：2
• 期：9
• 页码：2097-2101
• 全文大小：323K
• ISSN：2168-0485

文摘

Biomimetic sensitizers have evolved over millions of years to absorb and utilize sunlight and therefore are highly desirable to produce efficient, low cost, dye-sensitized photoelectrochemical solar cells. We report on the sensitization of TiO₂ nanotubes by bacteriochlorophyll-c (BChl c) extracted from photosynthetic bacteria. BChl c is notable for its high conversion efficiency inside the bacteria, which makes it a promising candidate for a naturally derived sensitizer for TiO₂. A photocurrent conversion efficiency of 0.1% was observed at 600鈥?00 nm, corresponding to the absorption peak in BChl c; a photoanode efficiency of 0.23% was measured at around 鈭?.1 V_SCE. Stability tests under simulated sunlight showed stable photocurrents over the course of 14 min. Mechanisms that currently limit the efficiency include the formation of BChl c aggregates on TiO₂, which may increase recombination, and possibly interface defects, which decrease charge injection to the nanotubes and trapping of photogenerated charges.

Keywords:

Biomimetic materials; TiO₂ nanotubes; Bacteriochlorophyll-c; Photoelectrochemistry; Dye-sensitized solar cells