Spontaneous Deposition of Os on Pt

The CV obtained after exposing a Pt(lll) electrode to a 0.1 mM OSCI3 + 0.1 M H2SO4 solution for 1 min is shown in Fig. 17. The feature at -75 mV on going in the negative direction is attributed to 

For 1-min deposition from 0.1 mM Os solution, only 39 5% of the islands are one layer high, and there is a significant multilayer growth even up to 5 monolayer height.19 In general, the tallest islands are the widest islands as well. One layer high islands typically 

The deposition of Os on Pt(l 11) occurred much faster than that of Ru. Comparing the surfaces obtained under the deposition conditions of 1 min from a 0.1 mM Os solution and 3 min from a 1 mM Ru solution (see Fig. 16a), a similar Os coverage vs. the Ru coverage limit was attained even though the concentration of Os in the depositing solution was ten times lower than that of Ru and the depositiontime was shorter. This was observed irrespective of the electrolyte composition or upon the change from perchloric to sulfuric acid medium. 

The multilayer growth appeared more significantly with Os, with 61 5% after only 1-min deposition from a 0.1 mM Os solution vs. only 24 3% multilayer growth on Ru/Pt(l 11) after 1-min deposition from a 1 mM Ru solution. There was a wider distribution of the island width and height for a single deposition of Os 

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