Template-free synthesis and photocatalytic activity of CdS nanorings

Cadmium sulfide (CdS) nanorings were synthesized through a convenient and economical chemical bath deposition (CBD) process without the use of any surfactant and template. SEM and TEM studies reveal that these nanorings are composed of connected nanoparticles. A self-assembly mechanism was proposed for the formation process of these nanorings on the basis of a series of time-dependent experiments. Furthermore, the photodegradation of rhodamine B (RhB) demonstrated that the CdS nanorings exhibited enhanced photocatalytic activity than that of commercial CdS powders under irradiation of visible light, which is due to the small crystallites can provide more reactive sites for photocatalytic reaction and the nanoscale facilitates the transfer of photogenerated electron-hole pairs to the surface. (C) 2013 Elsevier B.V. All rights reserved.