Hollow CdS nanoparticles formed through electrodeposition of Cd(OH)2 on graphite and treatment with H2S

Cd(OH)2 nanoparticles (NPs) were synthesized on graphite treated with plasma through electrochemical deposition in a solution of CdF2 saturated with O2. Cd(OH)2 NPs were formed from reaction of Cd2+ in solution with OH− generated on the graphite after reduction of O2. The Cd(OH)2 NPs were densely distributed on the surface and converted to form hollow CdS NPs via a thermal reaction with H2S at 300 °C. The resulting Cd(OH)2 and CdS NPs were characterized with measurements of X-ray photoelectron spectroscopy, atomic force microscopy, and high-resolution transmission electron microscopy. The latter results showed that the Cd(OH)2 and CdS NPs exhibited hexagonal and cubic crystalline structures, respectively. The photoluminescence of CdS NP showed a direct band at 2.47 eV and an indirect band at ∼1.67 eV.