Oxidation resistance of graphene-coated Cu and Cu/Ni alloy

The ability to protect refined metals from reactive environments is vital to many industrial and academic applications. Current solutions, however, typically introduce several negative effects, including increased thickness and changes in the metal physical properties. In this paper, we demonstrate for the first time the ability of graphene films grown by chemical vapor deposition to protect the surface of the metallic growth substrates of Cu and Cu/Ni alloy from air oxidation. SEM, Raman spectroscopy, and XPS studies show that the metal surface is well protected from oxidation even after heating at 200 \degree C in air for up to 4 hours. Our work further shows that graphene provides effective resistance against hydrogen peroxide. This protection method offers significant advantages and can be used on any metal that catalyzes graphene growth

In-situ examination of electrochemically formed Cu2O\mathrm{Cu_2O} layers by EXAFS in transmission

Cu$_2$O layers formed by the electrochemical reduction of saturated CuO$_{22}$− in 5 M KOH and their reduction to Cu metal are examined by EXAFS in an in-situ thin-layer electrochemical cell. Freshly precipitated Cu hydroxide and a saturated Cu(II) solution in LiOH solution were also studied in the same cell for comparison. The results show that the Cu$_2$O layers have a near-order structure almost identical with that of crystalline Cu$_2$O powder. This result supports the interpretation of the electrochemical and photoelectrochemical behaviour of some μm thick deposition layers and of passive layers on Cu on the basis of a modified semiconductor model