Temperature dependence of morphology, structural and optical properties of ZnS nanostructures synthesized by wet chemical route

ZnS nanostructures have been synthesized by simple wet chemical route and annealed at two different temperatures of 50 °C and 180 °C. From the measurements of transmission electron microscopy and contact-mode atomic force microscopy, it is found that annealed temperature changes the morphology from nanoparticles to nanorods. The optical properties of the synthesized ZnS nanomaterial have been characterized by UV–visible absorption spectroscopy and photoluminescence spectroscopy. The structural and elemental analyses were carried out by powder X-ray diffraction pattern and energy dispersive X-ray absorption spectroscopy, respectively. Absorption edge of the nanoparticles (295 nm) and nanorods (326 nm) was shifted towards shorter wavelength compared to bulk ZnS (337 nm) due to the quantum confinement effect.

Research highlights▶ ZnS nanoparticles and nanorods have been synthesized by wet chemical route. ▶ Higher annealing temperature influenced the change in morphology due to aggregation of the nanoparticles. ▶ The temperature dependent optical properties were investigated. ▶ Absorption edge of nanoparticles (295 nm) and nanorods (326 nm) were shifted towards shorter wavelength compared to bulk ZnS (337 nm) due to the quantum confinement effect. ▶ ZnS nanoparticles exhibit high photoluminescence intensity than that of ZnS nanorods annealed at 180 °C.