Etching of TiO2(110) Single-Crystal Surface with Aniline for Step Direction Control

Abstract

After subjecting a hydrofluoric acid treated and annealed TiO2(110) single-crystal substrate to immersion in an ethanol solution of aniline, a uniform step structure in the [001] direction was observed on the TiO2(110) surface without aniline. Since this finding is considered to control of the step direction on the TiO2(110) surface, the formed surface was discussed in detail and a model of the step line formation process was proposed. After immersing of TiO2(110) single-crystal substrate in an ethanol solution containing aniline, a uniform step structure in the [001] direction formed on the TiO2(110) surface although aniline was not existed. A reasonable model of the step line formation process was proposed. The present results lead to the novel method to control of the step direction on the TiO2(110) surface.