This study examines the dielectric properties of filled PVDF film and filled PVDF-TrFE film incorporated with 1, 3, 5, and 7 weight percentages of magnesium oxide (MgO) nanofillers. The metal-insulator-metal (MIM) configuration demonstrates PVDF/MgO with 7 weight percent of MgO which produced high dielectric constant (1 kHz) with low dielectric loss. The ATR-FTIR spectra of PVDF/MgO (7%) indicate wide bonding peaks at 840 cm-1 and 880 cm-1, assigned to -CH2 and -CF2 groups, respectively. This implies the presence of high content of β-crystals in the PVDF/MgO (7%) film. A shift in the peak was observed in the same film, from 1170 cm-1 to 1180 cm-1 suggesting possible transformation from γ-crystals to β-crystals. This film showed no apparent defect on its film surface. Thus, it established that PVDF incorporated with 7% MgO can be used to produce nanocomposite thin film for low-frequency electronic devices.

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The effects of annealing temperatures on the structure and photocurrent response of nanoporous iron oxide film prepared by anodization of iron foil in an ethylene glycol, NH 4 F, and H 2 O electrolyte were studied. The as-anodized anodic film was found to be rather amorphous and crystallized to predominantly a-Fe 2 O 3 upon annealing in nitrogen. Nitrogen was used as to reduce the thickening of the barrier layer which affects the photocurrent response of the oxide. However, annealing must be done above 300°C to produce crystalline oxide but must be kept lower than 500°C since high temperature promotes grain growth, destroying the nanoporous structure and also thickens the barrier layer, which significantly reduce the photocurrent of the film. Sample annealed at 450°C in nitrogen has the highest photocurrent of 1.04 mA/cm 2 (0.5 V versus Ag/AgCl in 1 M NaOH) compared to 0.13 mA/cm 2 at 0.5 V for air-annealed sample.

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ZrO nanotubes (ZrNTs) were produced by anodisation of zirconium foil in HO/NHF/ethylene glycol electrolyte. The as-anodised foils were then soaked in the anodising electrolyte for 12 h. Soaking weakens the adherence of the anodic layer from the substrate resulting in freestanding ZrNTs (FS-ZrNTs). Moreover, the presence of HO in the electrolyte also aids in weakening the adhesion of the film from the foil, as foil anodised in electrolyte without HO has good film adherence. The as-anodised FS-ZrNTs film was amorphous and crystallised to predominantly tetragonal phase upon annealing at >300 °C. Annealing must, however, be done at <500 °C to avoid monoclinic ZrO formation and nanotubes disintegration. FS-ZrNTs annealed at 450 °C exhibited the highest photocatalytic ability to degrade methyl orange (MO), whereby 82% MO degradation was observed after 5 h, whereas FS-ZrNTs with a mixture of monoclinic and tetragonal degraded 70% of MO after 5 h.