Gas induced reduction synthesis of Sb2Te3 and Bi0.5Sb1.5Te3 nanosheets and their evolvement mechanism

Abstract

Binary Sb2Te3 and ternary Bi0.5Sb1.5Te5 hexagonal nanosheets were synthesized by a gas-induced reduction (GIR) method, with Sb2(OCH2CH2O)3, TeO2 and Bi(NO3)3·5H2O as raw materials and hydrazine hydrate as a reducing agent. Structure and composition analyses reveal that the samples are of pure phase with corresponding atomic ratios. Electron microscopy analyses indicate that the as-prepared products are uniform and highly crystallized. The formation process was studied in detail by observing temperature-dependent and time-dependent products. It is found that the selective adsorption mechanism may be responsible for the growth of the hexagonal nanosheets. The GIR route is a simple and flexible route to the Bi–Sb–Te alloys and can be easily extended to the synthesis of other low-dimensional chalcogenide nanostructures.