Microstructures and Photodegradation Performance toward Methylene Orange of Sputtering-Assisted Decoration of ZnFe2O4 Crystallites onto TiO2 Nanorods

Abstract

In this study, TiO2–ZnFe2O4 (ZFO) core-shell nanorods with various ZFO crystallite thicknesses were synthesized through sputtering-deposited ZFO thin films onto the surfaces of TiO2 nanorods. By coupling the ZFO narrow bandgap oxide with TiO2, an enhanced photodegradation efficiency of methylene orange under irradiation was achieved. Structural analyses revealed that ZFO crystallites fully covered the surfaces of the TiO2 nanorods. The sputtering-deposited ZFO crystallites on the head region of the composite nanorods were markedly thicker than those covering the lateral region of the composite nanorods. The coverage of ZFO crystallites on the TiO2 nanorods led to an improved light harvesting, a decrease in the hole–electron recombination rate, as well as the enhanced photodegradation activity of the TiO2–ZFO heterostructures under irradiation. The optimized ZFO thickness on the head region of the composite nanorods was approximately 43 nm on average and that at the lateral region of the composite nanorods was 15 nm, which exhibited superior photodegradation ability to methylene orange and retained a stable photodegradation efficiency of approximately 97% after cycling tests. The results herein demonstrate that sputtering deposition of ZFO crystallite with tunable thickness is a promising approach to designing TiO2–ZFO composite nanorods with various ZFO coverage sizes and to adjust their photodegradation ability toward organic dyes.

Thermal Annealing Induced Controllable Porosity and Photoactive Performance of 2D ZnO Sheets

“…Comparatively, the drop degree of the absorbance spectra intensity is more intense for the RhB solution with the ZnO-H sheets at the given irradiation condition. For comparison, the photodegradation abilities of various ZnO sheets are displayed in Figure 8 d. The C/C o = I t /I o was used to evaluate the photodegradation degree, in which C o and C are the initial and residual concentration of the RhB dye at t = 0 and at any irradiation duration t, respectively and I t and I o are respectively the characteristic absorbance spectra intensities at irradiation duration t and at t = 0 [ 40 , 43 ]. Both porous ZnO sheets, i.e., ZnO-A and ZnO-H photocatalysts exhibited higher photocatalytic activities than pristine ZnO sheets.…”

Crystal Growth and Design of Disk/Filament ZnO-Decorated 1D TiO2 Composite Ceramics for Photoexcited Device Applications

“…TiO 2 nanorods can be synthesized through various physical and chemical methods. Hydrothermal crystal growth is preferred for synthesizing free-standing TiO 2 nanorod arrays because this method enables large-area crystal growth, facile process parameter control, and the use of flexible substrate materials [ 7 , 8 , 9 ]. ZnO crystals, such as nanosheets or nanoplates, are promising components for photoexcited nanodevices [ 10 , 11 , 12 ].…”

Coverage Layer Phase Composition-Dependent Photoactivity of One-Dimensional TiO2–Bi2O3 Composites

“…One-dimensional rods have been widely investigated for various binary oxides in photoactive applications because of their high surface-to-volume ratio and possibility for integration into diverse semiconductor nanodevices [1][2][3][4]. TiO 2 shows many excellent characteristics, such as low toxicity, easy fabrication, low cost, high stability and high photosensitivity [5].…”