Insight into Nucleation and Growth of Bi2–xSbxTe3 (x = 0–2) Nanoplatelets in Hydrothermal Synthesis
Year: 2017
Type: article
Abstract: Controlled wet chemical synthesis of nanomaterials with tailored structures and properties, especially by hydrothermal/solvothermal methods, is difficult due to the complicated nucleation and growth processes. Therefore, it is important to gain a deeper understanding of the formation mechanisms involved in hydrothermal/solvothermal processes. In the present study, the formation mechanisms of Bi 2– x Sb x Te 3 ( x = 0–2) nanoplatelets under hydrothermal conditions are studied by in situ synchrotron radiation powder X-ray diffraction (SR-PXRD). Synthesis using glucose as the reducing agent results in direct nucleation of Bi 2 Te 3 from Bi and Te precursors without the presence of any intermediate products, and the nucleation stage is completed in only about 1 min at 250 °C. When Sb is added, the nucleation process for Bi 2– x Sb x Te 3 becomes slower with increasing Sb content. Depending on the Sb content and reaction temperature, an intermediate product of elemental Te nanostructures forms, and it is found to direct the morphology of the final products. Within the duration of the measurements, Sb 2 Te 3 only forms at relatively high reaction temperatures due to the slower kinetics of the reaction. A two-stage nucleation mechanism is found for the formation of the ternary BiSbTe 3 with an initial nucleation stage of predominately Bi 2 Te 3 followed by a second stage of slower nucleation and alloying process to BiSbTe 3 . Both the composition and reaction temperatures affect the crystallization kinetics and crystallite growth mechanisms during synthesis of Bi 2– x Sb x Te 3 nanoplatelets.
Source: Chemistry of Materials
Institutions: Jiangsu University, Aarhus University
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2621316885