Single-crystalline Bi_2Te_3 nanosheets with uniform morphology via a simple, efficient, and high-yield microwave-assisted synthesis

摘要

A simple but efficient microwave-assisted method with high-yield products was applied to synthesize regular hexagon Bi_2Te_3 nanosheets. Rhombohedral Bi_2Te_3 with pure single crystalline phase was demonstrated by XRD patterns, HRTEM images, and SAED figures. The SEM and TEM images showed that the Bi_2Te_3 nanosheets were uniform, and that the average lengths of the hexagon sides were approximately 320 nm. The growth mechanisms and morphological transformations were systematically studied by controlling the reaction time, KOH concentration, and polyvinylpyrrolidone (PVP) dosage. This work has indicated that abundant KOH benefited the formation of uniform Bi_2Te_3 nanosheets without Te nanorods. Meanwhile, long reaction time and abundant PVP favored the formation of regular hexagon nanosheets with smooth surfaces.