Ordered dye-functionalized TiO_2 nanostructures for photoelectrochemical applications

摘要

Nanomaterials are advantageous for photoelectrochemical solar cell devices for high efficient conversion of light to electrical power due to its large surface area at which photoelectrochemical processes take place. One of the current solar cell systems utilizes dye-functionalized mesoporous titania films that consist of an interconnected network of nanometer-sized crystals. This type of structure imparts a large surface area for efficient dye adsorption and, thus, efficient electron-hole formation. This structure formed with connected nanoparticles possesses mesoscopic pores with an irregular and non-uniform pore structure. Such a structure imparts two problems: the transport of electrons through such a random structure, particularly through the necks between two particles, may become a limiting step, and the irregular mesoporous structure may not be ideal for dye assembly. In addition, a liquid electrolyte has to be used to accommodate such irregular mesoporous structures. In this paper, we propose to explore and present some preliminary results of ordered dye-functionalized titania nanostructures for potential enhancement of electron percolation pathways and light conversion. Such dye-sensitized, uniformly-sized, and unidirectionally-aligned titania nanorods and indium-tin-oxide nanorods coated with a titania layer have been synthesized and characterized for discussion.