CoFe2O4/graphene oxide hybrids have been successfully fabricated via a facile one-pot polyol route, followed by chemical conversion into FeCo/graphene hybrids under H2/NH3 atomosphere.
We demonstrate, both theoretically and experimentally, that cation vacancy can be the origin of ferromagnetism in intrinsic dilute magnetic semiconductors. The vacancies can be controlled to tune the ferromagnetism. Using Li-doped ZnO as an example, we found that while Li itself is nonmagnetic, it generates holes in ZnO, and its presence reduces the formation energy of Zn vacancy, and thereby stabilizes the zinc vacancy. Room temperature ferromagnetism with type conduction was observed in pulsed laser deposited ZnO:Li films with certain doping concentration and oxygen partial pressure.
We present a facile approach for the fabrication of a nanocomposite comprising α-Fe2O3 nanotubes (NTs) anchored on reduced graphene oxide (rGO) for electrochemical capacitors (ECs). The hollow tubular structure of the α-Fe2O3 NTs presents a high surface area for reaction, while the incorporation of rGO provides an efficient two-dimensional conductive pathway to allow fast, reversible redox reaction. As a result, the nanocomposite materials exhibit a specific capacitance which is remarkably higher (∼7 times) than α-Fe2O3 NTs alone. In addition, the nanocomposites show excellent cycling life and large negative potential window. These findings suggest that such nanocomposites are a promising candidate as negative electrodes in asymmetrical capacitors with neutral electrolytes.
26 July 2008 in The Journal of Physical Chemistry C