A simple hydrothermal route for synthesizing SnO₂quantum dots

Abstract

A simple hydrothermal process is proposed for synthesizing SnO2 quantum dots (QDs), in which hydrazine hydrate is used as the mineralizer instead of NaOH. X-ray diffraction, high-resolution transmission electron microscopy (HRTEM) and UV–vis diffuse reflectance spectroscopy (DRS) were employed to characterize the product. The HRTEM image shows that the diameters of the SnO2 nanoparticles fall into a small range of 2.3–3.1 nm, with the majority being less than the exciton Bohr radius of SnO2 (∼2.7 nm). Analysis of the DRS spectrum showed the band gap of the SnO2 QDs to be 3.88 eV, exhibiting a 0.28 eV blue shift from that of the bulk SnO2 (3.6 eV). The mechanism for hydrothermal synthesis of the SnO2 QDs using hydrazine hydrate as the mineralizer is discussed.