Hierarchical Bi2Se3 microrods: microwave-assisted synthesis, growth mechanism and their related properties

Abstract

Bi₂Se₃ microrods composed of nanoparticles have been successfully fabricated through a self-sacrificial template microwave-assisted method in the presence of a ethylene glycol (EG) solution, applying ascorbic acid (AA) as a reducing agent and soluble starch (SS) as a surfactant. The structure and morphology of the obtained products were characterized by powder X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM) and selected-area electron diffraction (SAED) techniques. Based on the time-dependent experiments, a possible formation mechanism was proposed. The electrical transport properties were investigated by measuring the electrical conductivity and the Seebeck coefficient at a temperature range of 298 to 523 K and the maximum power factor can be as high as 92 μW m⁻¹ K⁻² at 523 K. The intercalation behavior of Li ions into the obtained Bi₂Se₃ microrods was also investigated. The discharge capacity of the sample at room temperature can reach up to 870 mA h g⁻¹, indicating potential applications in electrochemical lithium intercalation and high-energy batteries.