Photoinduced synthesis of CdTe nanoparticles using Te-modified gold electrode in poly(vinyl pyrrolidone)-containing electrolyte

Photocathodic stripping of a pre-deposited tellurium film on a gold electrode in 0.1 M Na2SO4 electrolyte containing Cd2+ ions and poly(vinyl pyrrolidone) (PVP) was used as a route to the photoelectrosynthesis of CdTe nanoparticles. Thus illumination of a Te-modified gold surface generated Te(2-)species, which were removed from the surface into the bulk electrolyte containing Cd2+ and PVP by vigorous stirring. The reaction of Te2- and Cd2+ produced PVP-protected nanosized CdTe particles dispersed in solution in the size range 20-40 nm. In this approach, PVP played a critical role as a stabilizer to form discrete CdTe particles instead of larger (agglomerated) ones. Electrochemical quartz crystal microgravimetry was used to monitor stripping of Te films during the light illumination and the synthesized CdTe nanoparticles were characterized by scanning electron microscopy, energy dispersive X-ray analyses and laser Raman spectroscopy.