Template-free synthesis of Cd(OH)2 hollow spheres and its optical properties

Cd(OH)2 hollow spheres with diameters ranging from 4 to 6 μm were synthesized by a simple triethanolamine-assisted solvothermal route without using any templates. The effect of triethanolamine (TEA) concentration on the formation of the hollow spheres was investigated. The results indicated that the hollow spheres were composed of porous shells with nanoplates and TEA play a key role in controlling morphology of Cd(OH)2. A possible growth mechanism based on TEA-assisted assembly in solution is tentatively proposed. In addition, the optical absorption spectrum indicates that Cd(OH)2 hollow spheres have a direct band gap of 4.47 eV.

► We employ template-free reflux route for fabrication of Cd(OH)2 hollow spheres.
► TEA played a key role in the formation of Cd(OH)2 hollow spheres.
► A possible growth mechanism of the Cd(OH)2 hollow spheres was proposed.
► Cd(OH)2 hollow spheres have a direct band gap of 4.47 eV.