Durable Oxidation-Resistance of Copper via Light-Powered Bidentate Binding of Carbon Dioxide Anion Radicals

Introducing the durable oxidation resistance of refined copper on a large scale while retaining valuable physical properties has great operational and economic benefits for everyday industry but remains a challenge. Here, we report a strategy for the preparation of antioxidant copper under ambient UV/visible or high-energy irradiation using surface-coordinated carbon dioxide anion radicals (CO₂^•-). It is shown that effective adsorption of CO₂^•-on copper leads to further formation of bidentate formate multilayers, which hardly degrades surface characteristics but is resistant to chemical attack from a range of highly corrosive solutions such as H₂O₂, NaCl, Na₂S, and NaOH. Due to the universality of free radical production, the anticorrosion procedure requires no high temperature and pressure, as well as the specific container, enabling the processing of various sizes and shapes of copper materials. In addition, we demonstrated several practical advantages: the passivation of different shapes can be easily achieved under natural sunlight; using an industrial electron beam, 10 m oxidation-resistant copper foil can be made in only 90 s. The antioxidation method can use waste CO₂as CO₂^•-source, thus opening up a complementary opportunity for CO₂immobilization.