Morphology and photocurrent response of TiO2 nanotubes prepared in electrolytes containing different content of polyethylene glycol

Abstract

In order to investigate the effect of organic electrolytes on the photocurrent performance of TiO₂ nanotubes, four kinds of fluoride containing electrolyte were prepared. This work focuses on the effect of electrolyte on the photocurrent response of TiO₂ nanotubes. The results show that the electrolyte is an important influence on the photocurrent response. Appropriate proportion of polyethylene glycol (PEG) organic solvent can improve the performance of photocurrent response. The addition of excessive organic solvent will make TiO₂ nanotubes lose the ability of photocurrent response. Suitable surface porosity is a necessary condition for the sample to have photocurrent response. Too low porosity hinders the photoelectric property. The reason for the better photoelectric properties of the sample prepared in 50 wt% PEG electrolyte is explained by the ionic current and electronic current theory. The results show that a more stable ratio of accumulated charge by ionic and electronic currents per unit area creates a more stable photocurrent response when the voltage is increased from 40 V to 60 V.