Fig. 2: Fabrication and characterization of CeOx nanowire arrays with modified physicochemical properties.
a Schematic illustration of the fabrication process of physicochemical properties modulated CeOx nanowire arrays through solvent-assisted nanotransfer printing method combined with high-temperature annealing in various conditions: vacuum, Ar, and O2 atmosphere. b SEM images of the pristine CeOx nanowire array without annealing and CeOx nanowire arrays annealed with various conditions (as indicated) for 2 hours at 500 °C (scale bar, 500 nm). c TEM image of the CeOx nanowire treated with vacuum annealing (scale bar, 5 nm). d XRD spectra of the pristine CeOx nanowire arrays which have an amorphous state and CeOx nanowire arrays treated with various annealing conditions which have a polycrystalline state. e Characterization of the oxidation states of pristine CeOx nanowire arrays and CeOx nanowire arrays treated with various annealing conditions by using XPS.
