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

Abstract

Photocathodic stripping of a pre-deposited tellurium film on a gold electrode in 0.1 M Na 2 SO 4 electrolyte containing Cd 2+ 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 Cd 2+ and PVP by vigorous stirring. The reaction of Te 2-and Cd 2+ 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.

Photoelectrochemical Deposition of CdZnSe Thin Films on the Se-Modified Au Electrode

“…8,9 Figure 1A contains representative electrochemical, photo-electrochemical, and EQCM data for a polycrystalline Au electrode pre-modified with Se. Se was deposited by holding an Au electrode at −0.6 V for 120 s in 0.1 M Na2SO4 electrolyte containing 10 mM SeO2.…”

“…8,9 For voltammetry and film deposition, an EG&G Princeton Applied Research (PAR) 263A instrument equipped with Model M250/270 electrochemistry software was used. For EQCM, a Seiko EG&G Model QCA 917 instrument consisting of an oscillator module (QCA 917) and a 9 MHz AT-cut gold-coated quartz crystal (geometric area, 0.2 cm 2 ) as a working electrode were used.…”

“…1 Photocorrosion reaction is detrimental to the long-term stability of the photoelectrode and can be prevented by a suitable redox couple. 7 As an extension to the previous studies, 8,9 we utilized photocorrosion reaction to synthesize ternary semiconductor CdZnSe thin films. Photoexcitation of the pre-deposited p-Se generates Se 2− under light illumination and thus generated Se 2-species react with Cd 2+ and Zn 2+ in electrolyte to result in CdZnSe.…”

Electrochemical Synthesis of CdSe Nanoparticles Using a Se-modified RVC Electrode and Mercaptoacetic Acid as a Stabilizer

“…[12][13][14] While hot TOPO-based approaches require rather severe experimental conditions such as toxic chemicals and high temperatures, electrochemical methods can provide much more "green" environments. [15][16] Recently, CdTe NPs have been electrochemically synthesized using a Te disc electrode. 15 In this method, a Te disc electrode was cathodically polarized in the electrolyte containing Cd 2+ and mercaptoacetic acid (MAA), which served as a stabilizer.…”

“…15 We have developed a two-step method for the electrochemical synthesis of semiconductor films or particles. [16][17][18][19] This approach is based on initial electrochemical modification of the substrate with the chalcogen. Subsequent electrochemical reduction of chalcogen in an aqueous electrolyte solution dosed with the desired metal generates compound semiconductor films on the substrate surface or particles in bulk solution with stirring.…”