Properties of hydrothermally synthesized Zn2SnO4 nanoparticles using Na2CO3 as a novel mineralizer

Zn2SnO4 nanoparticles with a band gap of 2.96-3.36 eV were synthesized via a simple hydrothermal method using Na2CO3 as a new mineralizer. The effects of the concentration of Na2CO3 on the formation, morphology and optical properties of the Zn2SnO4 nanoparticles are discussed. Also, the reaction parameters, such as the reaction temperature and reaction time, were optimized. The as-synthesized Zn2SnO4 nanoparticles exhibit no impurity phases such as SnO2 and ZnO throughout the entire process, as confirmed by X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. Also, the formation of impurity free Zn2SnO4 nanoparticles in the presence of Na2CO3 is explained by a unique hydrothermal reaction sequence. The average particle size of the highly crystalline Zn2SnO4 nanoparticles was controllable by adjusting the mineralizer concentration, which enabled the facile tuning of the bandgap. From the photoluminescence (PL) study, two emission bands could be found after peak analysis, which are probably due to the presence of oxygen or cation vacancies generated during the hydrothermal process. These bands were shifted to lower frequencies as the concentration of the Na2CO3 mineralizer increased.