Optical properties and simultaneous synthesis of ZnS and ZnO nanoparticles via one reverse micellar system

ZnS nanoparticles were prepared by a simple reverse micelle reaction involving Triton X-100 as a surfactant. Meanwhile, ZnO nanoparticles were successfully synthesized followed by the calcination of the ZnS nanoparticles at 500 °C. The ZnS product, belonging to cubic lattice, are apparently spherical nanoparticles of average diameter 33 nm, and the obtained ZnO, belonging to hexagonal lattice, are approximately spherical ones of 12 nm. The average size of the ZnS nanoparticles depends on the water–surfactant ratio. Lower water–surfactant ratio results in smaller nanoparticle size, which gives rise to a larger blue-shift of their UV–visible and fluorescence spectra. The blue-shifted broad fluorescence emission is assigned to the recombination of photogenerated holes and electron-occupied oxygen vacancies. The conversion mechanism from ZnS to ZnO nanoparticles is discussed.