The controllable synthesis of chain-like TiO2 networks with multiwalled carbon nanotubes as templates and its application for dye-sensitized solar cells

Abstract

The anatase TiO2 nanostructure with large surface area and fast photoelectron-transfer channel can be an ideal structure for the fabrication of dye-sensitized solar cell (DSSC) photoelectrode. The high surface area can provide more sites for dye adsorption, while fast photoelectron-transfer channel can enhance the photogenerated electron transfer to complete the circuit. In this work, the chain-like TiO2 networks with large surface area and long particulate connection structure have been obtained through a facile wet-chemical method using multiwalled carbon nanotubes as templates. The diameter of TiO2 chain is ca. 15 nm and its interconnection degree can be controlled by adjusting the amount of reactive reagent. DSSC based with dense interconnection chain-like TiO2 network photoelectrode exhibits higher conversion efficiency (6.58 %), which is higher than that of DSSC based on photoelectrode with sparse interconnection chain-like TiO2 or conventional P25 nanoparticles under the same conditions. This is because it has higher surface area and the fastest interfacial charge transfer, which is proved by N2 sorption isotherms and electrochemical impedance spectra.