Influence of UV irradiation and ozone on atmospheric corrosion of bare silver

Abstract

The corrosion of Ag in an atmosphere of ozone and humidity with or without irradiation by ultraviolet (UV) light was investigated. A modified coulometric reduction technique was used, substituting sulphate solution for chloride solution, to prevent the spontaneous transformation of silver oxide corrosion product to chloride in the reduction solution. The presence of both ozone and UV radiation was required for fast corrosion of Ag to occur. The amount of corrosion product for a given exposure time increased with ozone concentration, whereas the relative humidity had little effect. An incubation time for the corrosion reaction was observed. The presence of both ozone and UV radiation were necessary for rapid corrosion because the photodissociation of ozone generates reactive atomic oxygen, which reacts with Ag rapidly to form Ag 2 O. The corrosion reaction on bare silver was minimally affected by the relative humidity in the environment, which is contrary to common atmospheric corrosion experience.

Atmospheric corrosion of Cu by UV, ozone and NaCl

“…The interaction between photons and newly formed Cu 2 O generates extra anodic photocurrent and doubles the corrosion rate. 38 A different effect of UV is possible in the presence of ozone because atomic oxygen can be generated by photolysis of ozone O 3 zhv (lv370 nm)?OzO 2 (6) Atomic oxygen is extremely aggressive; previous research has shown that atomic oxygen could result in faster corrosion of Ag than ozone, 13,14,39 especially at low RH. Therefore, the acceleration effect of UV could be larger in the presence of ozone.…”

Roughness characterization of silver oxide anodes for use in efficient top-illuminated organic solar cells

“…Fig. 3(a) shows that extending the period of surface treatment increased the^of the Ag film nonlinearly, due to an increase in the formation of AgO x and serious oxidization (larger x) [25][26][27]. With surface treatment less than 30 s, a sharp increase in^implied that the AgO x had effectively covered the surface of the Ag film.…”

Ancient silver artefacts: corrosion processes and preservation strategies

“…Then the corrosion layer acts as a transport barrier for both species. An incubation period is required for initiation of Ag corrosion under these conditions, associated with the chemisorption of atomic oxygen or OH radicals, which is the initial process before the start of the oxidation process [18].…”