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

Abstract

Single-crystalline BiFeO3 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 BiFeO3 nanosheets are around 140 and 230 nm, and thickness is about 30 nm. As a result, the BiFeO3 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 BiFeO3 powders prepared by solid-state reaction and sol–gel process respectively. The BiFeO3 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 BiFeO3 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 BiFeO3 nanosheets.