The electrochemical self-assembly of hierarchical dendritic Bi2Se3 nanostructures

Abstract

Bismuth selenide (Bi₂Se₃) has proven to be an important material in thermoelectric and topological insulator applications. We report here a simple electrochemical self-assembly route for the preparation of well-defined hierarchical dendritic Bi₂Se₃ nanostructures. Cyclic voltammetry was used to study the electrochemical reactions relevant to the growth of the prepared bismuth selenide. The compositional, morphological and structural properties of the deposited nanostructures were characterized using energy dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy and X-Ray Photoelectron Spectroscopy (XPS). The band gap of the prepared Bi₂Se₃ dendritic nanostructures was estimated to be 0.50 ± 0.01 eV by a UV-VIS-NIR spectrophotometer and the dendritic Bi₂Se₃ nanostructures showed an excellent photoelectrochemical activity. Additionally, based on the investigation on the evolution of the morphology and composition during electrochemical growth, a possible formation mechanism of the dendritic structures was concluded. Furthermore, the effects of some synthesis conditions on the morphologies of the deposited bismuth selenide nanostructures were studied.