Facile synthesis of BiFeO3 nanosheets with enhanced visible-light photocatalytic activity

Single-crystalline BiFeO 3 nanosheets with rectangular shape and exposed {101} facets were successfully synthesized via a facile hydrothermal method with low reaction temperature and short time (130 °C for 14 h). The process has advantages of energy saving, template and surfactant free, and no additional equipment in required. The average side lengths of BiFeO 3 nanosheets are around 140 and 230 nm, and thickness is about 30 nm. As a result, the BiFeO 3 nanosheets photocatalyst reaches as high as 89% of photodegradation efficiency of rhodamine B under 180 min visible light irradiation, which is about 4.68 and 2.41 times that of BiFeO 3 powders prepared by solid-state reaction and sol–gel process respectively. The BiFeO 3 nanosheets photocatalyst also exhibits a high reusability and storage stability for the photodegradation reaction. The internal electric fields produced due to the ferroelectric nature are perpendicular to the surfaces of BiFeO 3 nanosheets, which can promote the separation efficiency of photoinduced charges along [101] direction. While the nanoscale thickness structure can shorten the separation distance of photoinduced charges along [101] direction. These two factors all greatly suppress the recombination rate of e − /h + pairs, then leading to the improved photocatalytic kinetics of BiFeO 3 nanosheets.