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

Abstract

Disk- and filament-like ZnO crystals were decorated on one-dimensional TiO2 nanostructures (TiO2–ZnO) through various integrated physical and chemical synthesis methods. The morphology of the ZnO crystals on TiO2 varied with the chemical synthesis method used. ZnO nanodisks decorated with TiO2 nanorods (TiO2–ZnO–C) were synthesized using the chemical bath deposition method, and ZnO filament-like crystals decorated with TiO2 nanorods (TiO2–ZnO–H) were synthesized through the hydrothermal method. Compared with the pristine TiO2 nanorods, the as-synthesized TiO2–ZnO composites exhibited enhanced photophysiochemical performance. Furthermore, because of their fast electron transportation and abundant surface active sites, the ZnO nanodisks in the TiO2–ZnO–C composite exhibited a higher photoactivity than those in the TiO2–ZnO–H composite. The morphology and crystal quality of the ZnO decoration layer were manipulated using different synthesis methods to realize disk- or filament-like ZnO-decorated TiO2 composites with various photoactive performance levels.

Enhanced Photoelectrochemical Response of the ZnO/V2O5 Heterojunction Via Improved Visible-Light Absorption and Charge Carrier Separation

“…Also, Figure S7b shows the Nyquist plots for different V 2 O 5 photo-electrodes and a smaller value of charge transfer resistance (R ct ) for the V 2 O 5 _20 min electrode as compared to others, offering faster charge transfer at the interface of the electrode (V 2 O 5 )/electrolyte. 42 The Nyquist plot (Figure 5b) shows the smaller value of the charge transfer resistance (R ct ) for the ZnO/V 2 O 5 electrode as compared to pristine ZnO and V 2 O 5 thin-film electrodes, attributing to more efficient charge transfer, which occurs at the heterojunction of the thin-film sample across the electrode/electrolyte interface and is, therefore, consistent with photocurrent density results. Moreover, MS measurements were also used to determine the flat band potential (V fb ) and carrier density (N d ).…”

“…EIS plots obtained are shown in Figure S6b; the charge transfer resistance ( R ct ) is observed to be minimum for the ZnO_15 min thin-film sample as compared with other ZnO samples (ZnO_7 min and ZnO_30 min), as shown in Table , which produces better efficiency in the transfer of charge carriers at the interface of the ZnO electrode/electrolyte; therefore, this study is consistent with photocurrent density results. Also, Figure S7b shows the Nyquist plots for different V 2 O 5 photo-electrodes and a smaller value of charge transfer resistance ( R ct ) for the V 2 O 5 _20 min electrode as compared to others, offering faster charge transfer at the interface of the electrode (V 2 O 5 )/electrolyte . The Nyquist plot (Figure b) shows the smaller value of the charge transfer resistance ( R ct ) for the ZnO/V 2 O 5 electrode as compared to pristine ZnO and V 2 O 5 thin-film electrodes, attributing to more efficient charge transfer, which occurs at the heterojunction of the thin-film sample across the electrode/electrolyte interface and is, therefore, consistent with photocurrent density results.…”

Crystal Design and Photoactivity of TiO2 Nanorod Template Decorated with Nanostructured Bi2S3 Visible Light Sensitizer

“…Nanorod arrays of TiO 2 are beneficial to provide direct channels for electron transport, reducing the recombination probability of electrons in the transmission process. The rod morphology helps to improve the electron injection and collection efficiency of TiO 2 semiconductor [ 1 , 2 , 3 , 4 , 5 ]. However, the wide band gap nature of TiO 2 engenders poor response to visible light [ 6 , 7 ].…”

Nanostructures for Photonics and Optoelectronics

“…This Special Issue of Nanomaterials offers readers a compilation of some of the latest research in the field of the design, fabrication, characterization, and application of nanostructures in different fields of science. Articles published herein describe the fabrication of novel structures, such as the patterned metasurfaces developed by D. Huo et al [ 1 ] or the decoration of TiO 2 1D nanostructures with ZnO nanofilaments [ 2 ], and their characterization [ 3 ]. However, this Special Issue also aims to provide an overview of the applications of these nanostructures in different areas, such as the highly interesting gold nanostars used for biosensing developed by A. Tukova and colleagues [ 4 ], or the photonic applications of infiltrating nanostructured porous silicon with silver nanoparticles, a sort of nano-in-nano approach [ 5 ].…”