Title of article :
Prospect of determining copper sulfide nanoparticles by voltammetry: A potential artifact in supersaturated solutions
Author/Authors :
Krznari?، نويسنده , , Damir and Helz، نويسنده , , George R. and Ciglene?ki، نويسنده , , Irena، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2006
Pages :
8
From page :
207
To page :
214
Abstract :
Certain natural waters appear to contain copper sulfide (CuxS) nanoparticles in nanomolar concentrations (as Cu). These nanoparticles have been tentatively identified by the characteristic pH below which they deposit sulfide onto Hg electrodes. A proposed alternate approach to studying CuxS nanoparticles relies on their hydrophobicity, which causes them to sorb to Hg electrodes; there they can undergo reduction at −0.9 to −1.1 V vs. Ag/AgCl. However, solutions supersaturated with respect to Cu sulfide phases also form CuxS directly at Hg electrode surfaces. The voltammetric reduction peaks obtained from these deposits are not clearly distinguishable from those obtained from sorbed nanoparticles. Surface formation of CuxS, which appears to be limited to approximately two layers, involves a reaction between Cu amalgam and electrodeposited HgS. Surface-formed CuxS could be problematic in studies of CuxS nanoparticles, but this obstacle can be avoided by conducting voltammetric accumulations at potentials too negative for HgS electrodeposition (e.g. −0.85 V). Electroreduction of surface-formed CuxS occurs by a two-dimensional instantaneous hole nucleation and growth process.
Keywords :
copper sulfide , Nanoparticles , Cyclic voltammetry , Hanging Mercury Drop Electrode , Electrochemistry
Journal title :
Journal of Electroanalytical Chemistry
Serial Year :
2006
Journal title :
Journal of Electroanalytical Chemistry
Record number :
1672410
Link To Document :
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