The structure and photoluminescence of Bi4Ti3O12 nanoplates synthesized by hydrothermal method

Bismuth titanate (Bi4Ti3O12) nanoplates were synthesized by polyethylene glycol-assisted hydrothermal method at 200 °C. The as-prepared samples were investigated by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy and the room-temperature photoluminescence. The Bi4Ti3O12 nanoplates are single crystalline and orthorhombic perovskite structure with the average rim sizes of about 200 nm and thickness of 10-20 nm. One blue-green photoluminescence band centered at around 470.4 nm was observed at room temperature. The investigation of the effects of the annealing temperatures on room-temperature visible emission showed that the annealing temperatures or grain size play important roles for the intensities of blue-green light emission, and the oxygen vacancies should be responsible for this emission.