Room-temperature synthesis of three-dimensional porous ZnO@CuNi hybrid magnetic layers with photoluminescent and photocatalytic properties

Figures & data

Figure 1. Schematic flow of the synthesis of the ZnO@CuNi hybrid porous layers. From (a) to (b) hydrogen bubble-assisted electrodeposition of porous CuNi MF and from (c) to (d) impregnation of the CuNi scaffold with ZnO NPs suspension.

Figure 2. XRD patterns of (a) Cu₆₅Ni₃₅ (red) and ZnO@Cu₆₅Ni₃₅ (black) and (b) Cu₈₀Ni₂₀ (red) and ZnO@Cu₈₀Ni₂₀ (black). Peaks denoted by # and × belong to Cu-rich and Ni-rich phases, respectively. Two diffraction peaks at 33.06° and 34.36° belong to (100) Si and (100) α-Ti crystalline planes, respectively, of the substrate. Abbreviation: au = arbitrary units.

Figure 3. FE-SEM images of (a) the uncoated Cu₈₀Ni₂₀ MF; and the ZnO-coated Cu₈₀Ni₂₀ after (b) three consecutive impregnations (middle coverage) and (c) six consecutive impregnations (final coverage). In each column different magnifications of the three materials are shown.

Figure 4. (a) High-resolution TEM image of ZnO@Cu₈₀Ni₂₀ hybrid porous layer; (b) the SAED pattern of the ZnO NPs stacked on the CuNi layer. (c) High-resolution TEM image of an individual ZnO NP. (d) TEM image of as-prepared ZnO nanoparticles; magnified in the inset.

Figure 5. Room temperature hysteresis loops of the (a) Cu₈₀Ni₂₀ and ZnO@Cu₈₀Ni₂₀ and (b) Cu₆₅Ni₃₅ and ZnO@Cu₆₅Ni₃₅ samples.

Figure 6. (a) 3D projection images of the hybrid ZnO@Cu₈₀Ni₂₀ nanocomposite isosurface view by Imaris v.6.2.0 software. The 3D representation was obtained from a 50-section stack in steps of 3 μm. CuNi MF shows as gray color (reflection mode) whereas the ZnO component shows as green color (fluorescence). (b) Fluorescence spectrum obtained with the Lambda scan module of CSLM at a 5 nm resolution. Abbreviation: au = arbitrary units.

Figure 7. Fluorescence and reflection confocal micrographs (sample area: 621 μm x 621 μm) of the ZnO@Cu₈₀Ni₂₀ hybrid porous layer taken at different sections from the nanocomposite surface up to a total depth of 60 μm. Fluorescence microscopy was employed to visualize ZnO NP (in green). Reflection confocal microscopy was used to visualize the CuNi matrix (in gray).

Figure 8. C/C₀ plot of the degradation of RhB in the blank, in the presence of Cu₈₀Ni₂₀ MF, and in the presence of ZnO@Cu₈₀Ni₂₀ photocatalysts with middle and final coverages. The RhB degradation profile for ZnO-coated non-porous Cu-rich flat layer is also shown for comparison.