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. In particular, graphene prevents the formation of any oxide on the protected metal surfaces, thus allowing pure metal surfaces only one atom away from reactive environments. SEM, Raman spectroscopy, and XPS studies show that the metal surface is well protected from oxidation even after heating at 200 °C in air for up to 4 h. 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.

/pdf/oxidation-resistance-of-graphene-coated-cu-and-cu-ni-alloy-1ujpjs1lgl.pdf

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.

http://ntur.lib.ntu.edu.tw/bitstream/246246/90085/1/126.pdf

Aerobic granular sludge: Recent advances

Role of organic amendments on enhanced bioremediation of heavy metal(loid) contaminated soils

Porous CoFe2 O4 /C NRAs supported on nickel foam@NC (denoted as NF@NC-CoFe2 O4 /C NRAs) are directly fabricated by the carbonization of bimetal-organic framework NRAs grown on NF@poly-aniline(PANI), and they exhibit high electrocatalytic activity, low overpotential, and high stability for the oxygen evolution reaction in alkaline media.

Bimetal-Organic Framework Derived CoFe2O4/C Porous Hybrid Nanorod Arrays as High-Performance Electrocatalysts for Oxygen Evolution Reaction

Cation distribution and particle size effect on Raman spectrum of CoFe2O4

A dry mixture of ZnO and α-Fe2O3was annealed at 1200°C; the progress of the formation of the ferrite was monitored by XRD and XPS analyses at different time intervals. The presence of octahedral zinc cation was observed along with the regular tetrahedral Zn in the sample that had undergone 30 minute heat treatment. After three hours of heating, pure normal zinc ferrite was formed. The Zn 2p3/2peak binding energy, intensity and line shape were analyzed extensively to show the diffusion of ZnO and the growth of ferrite at different stages of heat treatment. Analysis of the Fe 2p3/2line-shape supported the substitution of Fe2+by zinc cations during ferrite formation. The binding energy values of the Zn 2p levels for stoichiometric and non-stoichiometric ferrites were also determined and surface segregation of the zinc was observed by XPS in the non-stoichiometric ferrites.

Formation of zinc ferrite by solid-state reaction and its characterization by XRD and XPS

Results obtained from the optical absorption and photoluminescence (PL) spectroscopy experiments have shown the formation of excitons in the silver-exchanged glass samples. These findings are reported here for the first time. Further, we investigate the dramatic changes in the photoemission properties of the silver-exchanged glass samples as a function of postannealing temperature. Observed changes are thought to be due to the structural rearrangements of silver and oxygen bonding during the heat treatments of the glass matrix. In fact, photoelectron spectroscopy does reveal these chemical transformations of silver-exchanged soda glass samples caused by the thermal effects of annealing in a high vacuum atmosphere. An important correlation between temperature-induced changes of the PL intensity and thermal growth of the silver nanoparticles has been established in this Letter through precise spectroscopic studies.

S.V. Narasimhan

Papers

Cation distribution and particle size effect on Raman spectrum of CoFe2O4

Formation of zinc ferrite by solid-state reaction and its characterization by XRD and XPS

Optical Absorption and Photoluminescence Spectroscopy of the Growth of Silver Nanoparticles

Solid state synthesis of Mg–Ni ferrite and characterization by XRD and XPS

Cobalt (II) imprinted chitosan for selective removal of cobalt during nuclear reactor decontamination