Adsorption of Methylene Blue on Titanate Nanotubes Synthesized with Ultra-Small Fe₃O₄ Nanoparticles

Abstract

Modified titanate nanotubes (TNT) were tested for their adsorption of methylene blue (MB) from water solutions. They were obtained from the TiO2 nanopowder using a standard alkaline hydrothermal method but in the stage of acid washing, when the titanate flakes begin to roll into nanotubes, magnetite nanoparticles were added. The Fe3O4 magnetic nanoparticles with diameter of around 2[Formula: see text]nm and 12[Formula: see text]nm were used in the tests. Significantly stronger adsorption of MB was observed when smaller nanoparticles were used compared to using larger nanoparticles and compared to the case of unmodified nanotubes. It was shown that the increased adsorption of MB is associated with a more negative value of [Formula: see text]-potential for titanates modified by the ultra-small nanoparticles. In the adsorption experiment, pH 7 was selected. These results may prove to be of great importance in the case of potential applications corresponding to the use of such material for wastewater purification.

The Use of Ultra-Small Fe3O4 Magnetic Nanoparticles for Hydrothermal Synthesis of Fe3+-Doped Titanate Nanotubes

“…Transforming TiO 2 nanopowder into TNTs yields a material with very large specific surface area [ 27 ] which, also possesses an ion-exchangeable layered structure [ 28 ]. Further modifications of TNTs by ion doping or decorating its surface with organic molecules and nanoparticles can enhance the adsorption properties of TNTs [ 29 , 30 , 31 ]. An additional advantage is that the titanate nanotubes does not contain toxic substances, as shown by recent studies [ 32 , 33 ].…”

Filtration of Nanoparticle Agglomerates in Aqueous Colloidal Suspensions Exposed to an External Radio-Frequency Magnetic Field

“…In this study, iron-oxide nanoparticles with an average size of about 10.5–11 nm (the PZC is about 6.6 [ 46 ]) were analyzed both as bare nanoparticles and the magnetic core of the silica-stabilized nanoparticles. The Fe O surface coated in silica, due to the presence of surface silanol groups, can easily react with a variety of coupling agents to covalently attach specific ligands.…”

One-Step Decoration of TiO2 Nanotubes with Fe3O4 Nanoparticles: Synthesis and Photocatalytic and Magnetic Properties

“…To the best of our knowledge, until now, only a few reports have focused on the preparation of TiO 2 NTs decorated or coated with magnetic NPs. 29,31,35,48,49 For example, a hydrothermal synthesis has been proposed to produce TiO 2 NTs decorated with Fe 3 O 4 NPs. 48 However, even this type of synthesis does not guarantee strong bonding of NPs to TiO 2 .…”

“…29,31,35,48,49 For example, a hydrothermal synthesis has been proposed to produce TiO 2 NTs decorated with Fe 3 O 4 NPs. 48 However, even this type of synthesis does not guarantee strong bonding of NPs to TiO 2 . By use of coprecipitation, Fe 3 O 4 NPs with a size of several nanometers were prepared and modified with oleic acid (OA) 49,50 and subsequently loaded within TiO 2 NTs by using a magnetic field.…”