Facile synthesis of ZnO nanocrystals in polyol

A new synthesis method of ZnO colloidal nanocrystals (CNCs) is presented in this work. This novel approach allows one to produce zinc oxide nanocrystals owing to a modified polyol process that makes use of 1,3-propanediol as a solvent. The structure and morphology of the nanoparticles were characterized by high-resolution transmission electron microscopy (HRTEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), and electron energy loss spectroscopy (EELS). The results showed that quasi-spherical ZnO nanocrystals with sizes in the range 4–7 nm were formed. Their morphology, size and colloidal stability are driven by the Polyol solvent. Under UV excitation, a strong visible photoluminescence emission, due to the radiative recombinations of the electron–hole pairs photo-generated in the ZnO nanoparticles, was observed. This optical property, together with the easy synthesis process, makes the ZnO CNCs a promising candidate for applications in optoelectronics and photocatalysis.

► ZnO colloidal nanocrystals with a mean diameter of 5 nm were synthesized in 1,3-propanediol.
► The polyol solvent 1,3-propanediol plays the roles of the stabilizer and the template.
► The PL emission covers the 400–800 nm spectral range.