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QUINHYDRONE AR
QUINHYDRONE AR
The so-called quinhydrone electrode, containing equivalent amounts of p-benzoquinone and hydroquinone, is used to determine hydrogen ion concentrations of unknown solutions.
The quinhydrone/methanol treatment has been reported to yield outstanding passivation of the H-terminated Si(100) surface. Here, we report on the mechanism of this process by comparing the resulting surface to that of freshly etched H-terminated Si, of Si with chemically grown oxide, and of Si treated with hydroquinone/methanol solution of the same concentration. We find that the benzoquinone moieties of the quinhydrone react with the surface to yield a Si-hydroquinone surface termination, while the methanol molecules bind as well to form methoxy-terminated Si.