Electroless Deposition of Gold

The plating bath consisted of 5 mL of a saturated hydroxylamine hydrochloride solution and 5 mL of a 1 wt% Na3Au(S03)2 solution (sodium gold sulfite was prepared according Ref. [67]). Both solutions were freshly mixed, stirred vigorously and the substrate was dipped into the mixture for 10 min at room temperature. 

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Saliba, R., Mingotaud, C., Argoul, F. and Ravaine, S. (2001) Electroless deposition of gold films under organized monolayers. 

Electroless Deposition of Gold. Okinaka (21) verified the mixed-potential theory for the case of electroless gold deposition. Eigure 8.6 shows that the partial cathodic... 

The gold nanotube membranes were prepared via the template synthesis [21,22] method by electroless deposition of gold along the pore walls of a polycarbonate template membrane [19,43]. The template was a commercially available filter (Osmonics), 6 p.m thick, with cylindrical 30 nm diameter pores and 6 x 10 pores per square centimeters of membrane surface area. 

The three amplification procedures used with this functionahzed Au-quartz crystal interface consisted of detection first using avidin and biotin-labelled liposomes, secondly using avidin-Au-nanoparticle conjugate and the catalysed electroless deposition of gold, and thirdly avidin-alkaline phosphatase interaction with 5-bromo-4-chloro-3-indolyl phosphate causing the biocatalysed precipitation of the insoluble product on the piezoelectric crystal. The separation of surface treatment outside the QCM cell coupled with... 

To find the conditions in which the electroless deposition of gold at Ni-P surfaces with an acceptable appearance and adhesion would be possible, the activation of Ni-P substrates with 10% HC1 solution or a mixture of 0.1 M NH4F and sodium sulfamate was investigated. The results showed that only low phosphorus alloys (P content less than 5 wt%) pretreated with ammonium fluoride/sodium sulfamate mixture can be used for a successful electroless gold plating from cyanide solution and hydrazine as a reducing agent.31... 

In the electroless deposition of gold from noncyanide solutions onto Ni-B and Ni-P surfaces, solutions containing thiosulfate and sulfite were used. The composition of a noncyanide solution for electroless deposition of gold used by Kato et al.32 is presented in Table 2. 

Composition of noncyanide solution for electroless deposition of gold used by Kato et al.32... 

It seems that the solution for electroless deposition of gold with ascorbic acid as a reducing agent developed by Sullivan and Kohl34 and presented in Table 3 produces very uniform coating with excellent adhesion, low porosity, good solderability, and very small crystallite size (about 25 nm).29... 

FIGURE 13.4 Scanning electron micrographs and representative illustrations of (a) 2D and (b) 3D NEEs grown by electroless deposition of gold within the pores of a nanoporous polymer membrane. (Reprinted with permission from Gasparac, R., Taft, B.J., Lapierre-Devlin, M.A. et al. Ultrasensitive electrocatalytic DNA detection at two- and three-dimensional nanoelectrodes, J. Am. Chem. Soc., 126, 12270-12271, 2004. Copyright 2004 American Chemical Society.)... 

Malel, E. and D. Mandler. 2008. Localized electroless deposition of gold nanoparticles using scanning electrochemical microscopy./. Electrvchem. Soc. 155 D459-D467. 

Okinaka Y, Kato M (2010) Electroless deposition of gold, fii Schlesinger M, Paunovic M (eds) Modem electroplating, 5th edn. John Wiley Sons, Inc., New York, NY, pp 483 98... 

The principles of electroless deposition on nanoporous membranes are exemplified by the Au deposition method developed in Charles Martin s laboratory" " for the template fabrication of NEEs, nanotubes, and other shaped gold materials. The electroless deposition of gold can be divided in three steps ... 

Early studies on the electroless deposition of gold from a sulfite-thiosulfate bath suggested that the active species was either the thiosulfate complex [54] or a mixed sulfite-thiosulfate complex [55]. In another study [53], the influence of sulfite addition on the cathodic reduction of the thiosulfate complex was shown to cause a negative shift of the reduction potential which was tentatively explained as being due to the formation of a mixed complex or to surface inhibition through sulfite adsorption at the electrode. This polarization effect was confirmed in a later study [56]. 

Electroless Deposition of Gold, Y. Okinaka and M. Kato, in Modem Electroplating, 4th Edition, eds. M. Schlesinger and M. Paunovic, John Wiley Sons, New York, 2000, pp. 705—727. 

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