Electroless versus electrodriven deposition of silver crystals in polyaniline role of silver anion complexes

• Published in: Electrochimica acta Vol. 50; no. 28; pp. 5616 - 5623
• Main Authors: IVANOV, S, TSAKOVA, V
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier 30.09.2005
• Subjects: Chemistry; Electrochemistry; Exact sciences and technology; General and physical chemistry; Miscellaneous (electroosmosis, electrophoresis, electrochromism, electrocrystallization, ...); Scanning electron microscopy; Electroless precipitation; Conjugated polymers; Silver Complexes; Electrocrystallization; Organic ligand; Plate electrode; Transition metal Complexes; EDTA; Experimental study; Polyaniline; Thiosulfato complex; Surface structure; Conducting polymers; Potentiodynamic method; Conjugated polymer; Silver; Silver anion complexes; Electrodeposition; Aqueous solution; Electroless plating; Aniline polymer; Modified material
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2005.03.040

Electrocrystallization of silver is studied at polyaniline-coated electrodes using silver cations and two silver anion complexes (silver thiosulfate and silver-EDTA) as reducing species. Use of the silver thiosulfate complex results in a significant shift of the silver deposition potential window in the negative direction and highly impeded metal crystallization. The silver cation and silver-EDTA plating solutions allow to perform both electrodriven and electroless metal deposition. Number and size of silver crystals obtained by the two deposition methods in the different plating solutions are compared. Electroless precipitation in the silver-EDTA solution results in the highest number (~10(8) cm-2) of small-sized crystals. This result is discussed in terms of the special role of the EDTA anions for the redox state of the polyaniline layers. It is demonstrated that factors such as polyaniline redox charge, concentration of reducing ions and dipping time allow effective control over the amount of electroless deposited metal.