Composition of Copper Tarnish Products Formed in Moist Air with Trace Levels of Pollutant Gas: Hydrogen Sulfide and Sulfur Dioxide/Hydrogen Sulfide
Abstract
The objective of the work reported here was to characterize the tarnish products formed on copper during the early stages
of exposure to moist air with trace levels of pollutant gas, in particular hydrogen sulfide and sulfur dioxide/hydrogen sulfide.
As determined by x‐ray photoelectron spectroscopy and coulometric reduction (chronopotentiometry), the exposure of copper
to 50 ppb hydrogen sulfide at 23°C and 70% relative humidity was found to produce a tarnish layer consisting of
and
. Addition of 75 ppb sulfur dioxide to a 50 ppb hydrogen sulfide, moist air environment at 23°C and 70% relative humidity
encouraged the growth of a thicker tarnish product layer, with proportionally more
in the
structure.
- Manuscript received October 28, 1994.
- Revised manuscript received May 31, 1995.
- Available electronically November 1, 1995.
- © 1995 ECS - The Electrochemical Society











