The facile preparation of Ag decorated TiO₂/ZnO nanotubes and their potent photocatalytic degradation efficiency

Abstract

nanotubes were produced using a simple and novel approach combining electrospinning with an impregnation calcination method. Using a photoreduction method, silver nanoparticles (AgNps) were successfully decorated on the surface of nanotubes. During the synthesis process, the electrospinning procedure provided sacrificial templates for the fabrication of hollow nanotubes by producing PAN nanofibers, which can be immobilized on the TiO 2 surface through a soaking method. Later, the composite nanofibers of TiO 2 /PAN were calcined into pure TiO 2 nanotubes after complete combustion of the sacrificial templates. The morphology of the samples was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The structure and components of the samples were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). Upon blending ZnO into TiO 2 , a new crystallite ZnTiO 3 was formed in addition to the ZnO and TiO 2 crystallites, and the ultraviolet light absorption efficiency was detected using UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic properties were evaluated using the degradation of methyl orange (MO) dye. As observed from the results, the Ag/TiO 2 /ZnO nanotubes could degrade MO efficiently under UV irradiation, which showed excellent photocatalytic activity compared to pure TiO 2 . The synthetic mechanism of Ag/TiO 2 / ZnO nanotubes and the mechanism for the enhanced photocatalytic activity have been proposed.

Ag Nanoparticles Decorated TiO2 Thin Films with Enhanced Photocatalytic Activity

“…Recorded Ti 2p spectrum indicated two main peaks at 459.2 and 464.8 eV which correspond to Ti 2p 3/2 and Ti 2p 1/2 orbitals, respectively . The binding energy of 5.6 eV can be attributed to Ti 4+ (indicating TiO 2 ) in Figure a . The O 1s peak exhibited two chemical states (Figure b) which could be attributed to lattice oxygen surface oxygen and Ag oxide .…”

“…Various methods such as hydrothermal synthesis, sol‐gel, spray‐pyrolysis, chemical reduction, reactive sputtering, electrochemical deposition, and photocatalytic deposition have been reported to prepare Ag NPs on TiO 2 . The photocatalytic deposition is considered an effective method to prepare Ag NPs directly on the TiO 2 surface, which provides a strong adhesion between particles and the surface .…”

Construction of Ag-modified TiO2/ZnO heterojunction nanotree arrays with superior photocatalytic and photoelectrochemical properties

“…The equilibrium Fermi level (E f ) of ZnO/Ag heterojunction is lower than the bottom energy level of CB of ZnO. 54,55 Therefore, the photoexcited electrons can be transferred from the CB of the ZnO nanorods to the Fermi level of the metal Ag as the electron trap, 56 thereby effectively promoting the separation of the photogenerated electron-hole. Photogenerated electrons e À are captured by O 2 on the surface of TiO 2 and Ag.…”

Plasmonic Ag decorated CdMoO4 as an efficient photocatalyst for solar hydrogen production

“…Previous reports show that decoration of Ag clusters on the surface of the semiconductor tunes the surface properties and improves the interfacial charge separation efficiency between the noble metal and the semiconductor photocatalyst. 52,53 Furthermore, the band structure of the semiconductor also affects the photocatalytic activity. In the case of CdMoO 4, the VB is predominantly contributed by occupied O 2p orbitals and Cd 4S orbitals, whereas the bottom of the conduction band consists of empty Mo 4d orbitals.…”