Ionic liquid assisted hydrothermal preparation of TiO2 with largely enhanced photocatalytic performance originated from effective separation of photoinduced carriers

Abstract

In this paper, TiO2 with enhanced photocatalytic activity was prepared with the aid of ionic liquid 1-ethyl-3-methylimidazolium hexafluorophosphate ([BMIm]PF6) through a conventional hydrothermal method. The effects of different amounts of [BMIm]PF6 on the preparation and corresponding photocatalytic activity of TiO2 were investigated. Preparation of TiO2 was optimized by controlling the mass ratio of [BMIm]PF6 and TiO2. Photocatalytic property of TiO2 prepared was investigated using RhB as a simulated pollutant. The results show that TiO2 prepared with the aid of [BMIm]PF6 exhibits superior photocatalytic activity to the reference TiO2, when the mass ratio of [BMIm]PF6/TiO2 is 8%, TiO2 prepared has the highest separation rate of photogenerated charge pairs, leading to the highest photocatalytic activity. The enhanced photocatalytic performance of TiO2 prepared with the aid of [BMIm]PF6 is attributable to high surface hydroxyl content and enhanced separation of photoinduced charge pairs.